10 comandos de Strace para solucionar problemas y depurar procesos de Linux


strace es una poderosa herramienta de línea de comandos para depurar y solucionar problemas de programas en sistemas operativos similares a Unix como Linux. Captura y registra todas las llamadas al sistema realizadas por un proceso y las señales recibidas por el proceso.

Muestra el nombre de cada llamada al sistema junto con sus argumentos entre paréntesis y su valor de retorno al error estándar; opcionalmente, también puede redirigirlo a un archivo.

En este artículo, explicaremos 10 ejemplos de comandos de strace para solucionar problemas y depurar programas y procesos en un sistema Linux.

Cómo instalar la herramienta de monitoreo de procesos Strace en Linux

Si strace no está preinstalado en su sistema Linux, ejecute el comando apropiado a continuación para su distribución para instalarlo.

$ sudo apt install strace	#Debian/Ubuntu 
# yum install strace		#RHEL/CentOS
# dnf install strace		#Fedora 22+

En caso de que un programa falle o se comporte de una manera inesperada, puede revisar las llamadas a sus sistemas para obtener una pista de lo que sucedió exactamente durante su ejecución. Como veremos más adelante, las llamadas al sistema se pueden categorizar en diferentes eventos: las relacionadas con la gestión de procesos, las que toman un archivo como argumento, las que involucran redes, mapeo de memoria, señales, IPC y también llamadas al sistema relacionadas con descriptores de archivos.

Puede ejecutar un programa/comando con strace o pasarle un PID usando la opción -p como en los siguientes ejemplos.

1. Rastrear llamadas al sistema de comandos de Linux

Simplemente puede ejecutar un comando con strace como este, aquí estamos rastreando todas las llamadas al sistema realizadas por el comando df.

$ strace df -h

execve("/bin/df", ["df", "-h"], [/* 50 vars */]) = 0
brk(NULL)                               = 0x136e000
access("/etc/ld.so.nohwcap", F_OK)      = -1 ENOENT (No such file or directory)
mmap(NULL, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f82f78fd000
access("/etc/ld.so.preload", R_OK)      = -1 ENOENT (No such file or directory)
open("/etc/ld.so.cache", O_RDONLY|O_CLOEXEC) = 3
fstat(3, {st_mode=S_IFREG|0644, st_size=147662, ...}) = 0
mmap(NULL, 147662, PROT_READ, MAP_PRIVATE, 3, 0) = 0x7f82f78d8000
close(3)                                = 0
access("/etc/ld.so.nohwcap", F_OK)      = -1 ENOENT (No such file or directory)
open("/lib/x86_64-linux-gnu/libc.so.6", O_RDONLY|O_CLOEXEC) = 3
read(3, "7ELF
$ strace df -h
execve("/bin/df", ["df", "-h"], [/* 50 vars */]) = 0
brk(NULL)                               = 0x136e000
access("/etc/ld.so.nohwcap", F_OK)      = -1 ENOENT (No such file or directory)
mmap(NULL, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f82f78fd000
access("/etc/ld.so.preload", R_OK)      = -1 ENOENT (No such file or directory)
open("/etc/ld.so.cache", O_RDONLY|O_CLOEXEC) = 3
fstat(3, {st_mode=S_IFREG|0644, st_size=147662, ...}) = 0
mmap(NULL, 147662, PROT_READ, MAP_PRIVATE, 3, 0) = 0x7f82f78d8000
close(3)                                = 0
access("/etc/ld.so.nohwcap", F_OK)      = -1 ENOENT (No such file or directory)
open("/lib/x86_64-linux-gnu/libc.so.6", O_RDONLY|O_CLOEXEC) = 3
read(3, "\177ELF\2\1\1\3\0\0\0\0\0\0\0\0\3\0>\0\1\0\0\0P\t\2\0\0\0\0\0"..., 832) = 832
fstat(3, {st_mode=S_IFREG|0755, st_size=1868984, ...}) = 0
mmap(NULL, 3971488, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x7f82f7310000
...
$ strace df -h
execve("/bin/df", ["df", "-h"], [/* 50 vars */]) = 0
brk(NULL)                               = 0x136e000
access("/etc/ld.so.nohwcap", F_OK)      = -1 ENOENT (No such file or directory)
mmap(NULL, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f82f78fd000
access("/etc/ld.so.preload", R_OK)      = -1 ENOENT (No such file or directory)
open("/etc/ld.so.cache", O_RDONLY|O_CLOEXEC) = 3
fstat(3, {st_mode=S_IFREG|0644, st_size=147662, ...}) = 0
mmap(NULL, 147662, PROT_READ, MAP_PRIVATE, 3, 0) = 0x7f82f78d8000
close(3)                                = 0
access("/etc/ld.so.nohwcap", F_OK)      = -1 ENOENT (No such file or directory)
open("/lib/x86_64-linux-gnu/libc.so.6", O_RDONLY|O_CLOEXEC) = 3
read(3, "\177ELF\2\1\1\3\0\0\0\0\0\0\0\0\3\0>\0\1\0\0\0P\t\2\0\0\0\0\0"..., 832) = 832
fstat(3, {st_mode=S_IFREG|0755, st_size=1868984, ...}) = 0
mmap(NULL, 3971488, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x7f82f7310000
...
$ strace df -h
execve("/bin/df", ["df", "-h"], [/* 50 vars */]) = 0
brk(NULL)                               = 0x136e000
access("/etc/ld.so.nohwcap", F_OK)      = -1 ENOENT (No such file or directory)
mmap(NULL, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f82f78fd000
access("/etc/ld.so.preload", R_OK)      = -1 ENOENT (No such file or directory)
open("/etc/ld.so.cache", O_RDONLY|O_CLOEXEC) = 3
fstat(3, {st_mode=S_IFREG|0644, st_size=147662, ...}) = 0
mmap(NULL, 147662, PROT_READ, MAP_PRIVATE, 3, 0) = 0x7f82f78d8000
close(3)                                = 0
access("/etc/ld.so.nohwcap", F_OK)      = -1 ENOENT (No such file or directory)
open("/lib/x86_64-linux-gnu/libc.so.6", O_RDONLY|O_CLOEXEC) = 3
read(3, "\177ELF\2\1\1\3\0\0\0\0\0\0\0\0\3\0>\0\1\0\0\0P\t\2\0\0\0\0\0"..., 832) = 832
fstat(3, {st_mode=S_IFREG|0755, st_size=1868984, ...}) = 0
mmap(NULL, 3971488, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x7f82f7310000
...
$ strace df -h
execve("/bin/df", ["df", "-h"], [/* 50 vars */]) = 0
brk(NULL)                               = 0x136e000
access("/etc/ld.so.nohwcap", F_OK)      = -1 ENOENT (No such file or directory)
mmap(NULL, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f82f78fd000
access("/etc/ld.so.preload", R_OK)      = -1 ENOENT (No such file or directory)
open("/etc/ld.so.cache", O_RDONLY|O_CLOEXEC) = 3
fstat(3, {st_mode=S_IFREG|0644, st_size=147662, ...}) = 0
mmap(NULL, 147662, PROT_READ, MAP_PRIVATE, 3, 0) = 0x7f82f78d8000
close(3)                                = 0
access("/etc/ld.so.nohwcap", F_OK)      = -1 ENOENT (No such file or directory)
open("/lib/x86_64-linux-gnu/libc.so.6", O_RDONLY|O_CLOEXEC) = 3
read(3, "\177ELF\2\1\1\3\0\0\0\0\0\0\0\0\3\0>\0\1\0\0\0P\t\2\0\0\0\0\0"..., 832) = 832
fstat(3, {st_mode=S_IFREG|0755, st_size=1868984, ...}) = 0
mmap(NULL, 3971488, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x7f82f7310000
...
$ strace df -h
execve("/bin/df", ["df", "-h"], [/* 50 vars */]) = 0
brk(NULL)                               = 0x136e000
access("/etc/ld.so.nohwcap", F_OK)      = -1 ENOENT (No such file or directory)
mmap(NULL, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f82f78fd000
access("/etc/ld.so.preload", R_OK)      = -1 ENOENT (No such file or directory)
open("/etc/ld.so.cache", O_RDONLY|O_CLOEXEC) = 3
fstat(3, {st_mode=S_IFREG|0644, st_size=147662, ...}) = 0
mmap(NULL, 147662, PROT_READ, MAP_PRIVATE, 3, 0) = 0x7f82f78d8000
close(3)                                = 0
access("/etc/ld.so.nohwcap", F_OK)      = -1 ENOENT (No such file or directory)
open("/lib/x86_64-linux-gnu/libc.so.6", O_RDONLY|O_CLOEXEC) = 3
read(3, "\177ELF\2\1\1\3\0\0\0\0\0\0\0\0\3\0>\0\1\0\0\0P\t\2\0\0\0\0\0"..., 832) = 832
fstat(3, {st_mode=S_IFREG|0755, st_size=1868984, ...}) = 0
mmap(NULL, 3971488, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x7f82f7310000
...
$ strace df -h
execve("/bin/df", ["df", "-h"], [/* 50 vars */]) = 0
brk(NULL)                               = 0x136e000
access("/etc/ld.so.nohwcap", F_OK)      = -1 ENOENT (No such file or directory)
mmap(NULL, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f82f78fd000
access("/etc/ld.so.preload", R_OK)      = -1 ENOENT (No such file or directory)
open("/etc/ld.so.cache", O_RDONLY|O_CLOEXEC) = 3
fstat(3, {st_mode=S_IFREG|0644, st_size=147662, ...}) = 0
mmap(NULL, 147662, PROT_READ, MAP_PRIVATE, 3, 0) = 0x7f82f78d8000
close(3)                                = 0
access("/etc/ld.so.nohwcap", F_OK)      = -1 ENOENT (No such file or directory)
open("/lib/x86_64-linux-gnu/libc.so.6", O_RDONLY|O_CLOEXEC) = 3
read(3, "\177ELF\2\1\1\3\0\0\0\0\0\0\0\0\3\0>\0\1\0\0\0P\t\2\0\0\0\0\0"..., 832) = 832
fstat(3, {st_mode=S_IFREG|0755, st_size=1868984, ...}) = 0
mmap(NULL, 3971488, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x7f82f7310000
...
$ strace df -h
execve("/bin/df", ["df", "-h"], [/* 50 vars */]) = 0
brk(NULL)                               = 0x136e000
access("/etc/ld.so.nohwcap", F_OK)      = -1 ENOENT (No such file or directory)
mmap(NULL, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f82f78fd000
access("/etc/ld.so.preload", R_OK)      = -1 ENOENT (No such file or directory)
open("/etc/ld.so.cache", O_RDONLY|O_CLOEXEC) = 3
fstat(3, {st_mode=S_IFREG|0644, st_size=147662, ...}) = 0
mmap(NULL, 147662, PROT_READ, MAP_PRIVATE, 3, 0) = 0x7f82f78d8000
close(3)                                = 0
access("/etc/ld.so.nohwcap", F_OK)      = -1 ENOENT (No such file or directory)
open("/lib/x86_64-linux-gnu/libc.so.6", O_RDONLY|O_CLOEXEC) = 3
read(3, "\177ELF\2\1\1\3\0\0\0\0\0\0\0\0\3\0>\0\1\0\0\0P\t\2\0\0\0\0\0"..., 832) = 832
fstat(3, {st_mode=S_IFREG|0755, st_size=1868984, ...}) = 0
mmap(NULL, 3971488, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x7f82f7310000
...
$ strace df -h
execve("/bin/df", ["df", "-h"], [/* 50 vars */]) = 0
brk(NULL)                               = 0x136e000
access("/etc/ld.so.nohwcap", F_OK)      = -1 ENOENT (No such file or directory)
mmap(NULL, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f82f78fd000
access("/etc/ld.so.preload", R_OK)      = -1 ENOENT (No such file or directory)
open("/etc/ld.so.cache", O_RDONLY|O_CLOEXEC) = 3
fstat(3, {st_mode=S_IFREG|0644, st_size=147662, ...}) = 0
mmap(NULL, 147662, PROT_READ, MAP_PRIVATE, 3, 0) = 0x7f82f78d8000
close(3)                                = 0
access("/etc/ld.so.nohwcap", F_OK)      = -1 ENOENT (No such file or directory)
open("/lib/x86_64-linux-gnu/libc.so.6", O_RDONLY|O_CLOEXEC) = 3
read(3, "\177ELF\2\1\1\3\0\0\0\0\0\0\0\0\3\0>\0\1\0\0\0P\t\2\0\0\0\0\0"..., 832) = 832
fstat(3, {st_mode=S_IFREG|0755, st_size=1868984, ...}) = 0
mmap(NULL, 3971488, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x7f82f7310000
...
$ strace df -h
execve("/bin/df", ["df", "-h"], [/* 50 vars */]) = 0
brk(NULL)                               = 0x136e000
access("/etc/ld.so.nohwcap", F_OK)      = -1 ENOENT (No such file or directory)
mmap(NULL, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f82f78fd000
access("/etc/ld.so.preload", R_OK)      = -1 ENOENT (No such file or directory)
open("/etc/ld.so.cache", O_RDONLY|O_CLOEXEC) = 3
fstat(3, {st_mode=S_IFREG|0644, st_size=147662, ...}) = 0
mmap(NULL, 147662, PROT_READ, MAP_PRIVATE, 3, 0) = 0x7f82f78d8000
close(3)                                = 0
access("/etc/ld.so.nohwcap", F_OK)      = -1 ENOENT (No such file or directory)
open("/lib/x86_64-linux-gnu/libc.so.6", O_RDONLY|O_CLOEXEC) = 3
read(3, "\177ELF\2\1\1\3\0\0\0\0\0\0\0\0\3\0>\0\1\0\0\0P\t\2\0\0\0\0\0"..., 832) = 832
fstat(3, {st_mode=S_IFREG|0755, st_size=1868984, ...}) = 0
mmap(NULL, 3971488, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x7f82f7310000
...
$ strace df -h
execve("/bin/df", ["df", "-h"], [/* 50 vars */]) = 0
brk(NULL)                               = 0x136e000
access("/etc/ld.so.nohwcap", F_OK)      = -1 ENOENT (No such file or directory)
mmap(NULL, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f82f78fd000
access("/etc/ld.so.preload", R_OK)      = -1 ENOENT (No such file or directory)
open("/etc/ld.so.cache", O_RDONLY|O_CLOEXEC) = 3
fstat(3, {st_mode=S_IFREG|0644, st_size=147662, ...}) = 0
mmap(NULL, 147662, PROT_READ, MAP_PRIVATE, 3, 0) = 0x7f82f78d8000
close(3)                                = 0
access("/etc/ld.so.nohwcap", F_OK)      = -1 ENOENT (No such file or directory)
open("/lib/x86_64-linux-gnu/libc.so.6", O_RDONLY|O_CLOEXEC) = 3
read(3, "\177ELF\2\1\1\3\0\0\0\0\0\0\0\0\3\0>\0\1\0\0\0P\t\2\0\0\0\0\0"..., 832) = 832
fstat(3, {st_mode=S_IFREG|0755, st_size=1868984, ...}) = 0
mmap(NULL, 3971488, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x7f82f7310000
...
$ strace df -h
execve("/bin/df", ["df", "-h"], [/* 50 vars */]) = 0
brk(NULL)                               = 0x136e000
access("/etc/ld.so.nohwcap", F_OK)      = -1 ENOENT (No such file or directory)
mmap(NULL, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f82f78fd000
access("/etc/ld.so.preload", R_OK)      = -1 ENOENT (No such file or directory)
open("/etc/ld.so.cache", O_RDONLY|O_CLOEXEC) = 3
fstat(3, {st_mode=S_IFREG|0644, st_size=147662, ...}) = 0
mmap(NULL, 147662, PROT_READ, MAP_PRIVATE, 3, 0) = 0x7f82f78d8000
close(3)                                = 0
access("/etc/ld.so.nohwcap", F_OK)      = -1 ENOENT (No such file or directory)
open("/lib/x86_64-linux-gnu/libc.so.6", O_RDONLY|O_CLOEXEC) = 3
read(3, "\177ELF\2\1\1\3\0\0\0\0\0\0\0\0\3\0>\0\1\0\0\0P\t\2\0\0\0\0\0"..., 832) = 832
fstat(3, {st_mode=S_IFREG|0755, st_size=1868984, ...}) = 0
mmap(NULL, 3971488, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x7f82f7310000
...
$ strace df -h
execve("/bin/df", ["df", "-h"], [/* 50 vars */]) = 0
brk(NULL)                               = 0x136e000
access("/etc/ld.so.nohwcap", F_OK)      = -1 ENOENT (No such file or directory)
mmap(NULL, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f82f78fd000
access("/etc/ld.so.preload", R_OK)      = -1 ENOENT (No such file or directory)
open("/etc/ld.so.cache", O_RDONLY|O_CLOEXEC) = 3
fstat(3, {st_mode=S_IFREG|0644, st_size=147662, ...}) = 0
mmap(NULL, 147662, PROT_READ, MAP_PRIVATE, 3, 0) = 0x7f82f78d8000
close(3)                                = 0
access("/etc/ld.so.nohwcap", F_OK)      = -1 ENOENT (No such file or directory)
open("/lib/x86_64-linux-gnu/libc.so.6", O_RDONLY|O_CLOEXEC) = 3
read(3, "\177ELF\2\1\1\3\0\0\0\0\0\0\0\0\3\0>\0\1\0\0\0P\t\2\0\0\0\0\0"..., 832) = 832
fstat(3, {st_mode=S_IFREG|0755, st_size=1868984, ...}) = 0
mmap(NULL, 3971488, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x7f82f7310000
...
$ strace df -h
execve("/bin/df", ["df", "-h"], [/* 50 vars */]) = 0
brk(NULL)                               = 0x136e000
access("/etc/ld.so.nohwcap", F_OK)      = -1 ENOENT (No such file or directory)
mmap(NULL, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f82f78fd000
access("/etc/ld.so.preload", R_OK)      = -1 ENOENT (No such file or directory)
open("/etc/ld.so.cache", O_RDONLY|O_CLOEXEC) = 3
fstat(3, {st_mode=S_IFREG|0644, st_size=147662, ...}) = 0
mmap(NULL, 147662, PROT_READ, MAP_PRIVATE, 3, 0) = 0x7f82f78d8000
close(3)                                = 0
access("/etc/ld.so.nohwcap", F_OK)      = -1 ENOENT (No such file or directory)
open("/lib/x86_64-linux-gnu/libc.so.6", O_RDONLY|O_CLOEXEC) = 3
read(3, "\177ELF\2\1\1\3\0\0\0\0\0\0\0\0\3\0>\0\1\0\0\0P\t\2\0\0\0\0\0"..., 832) = 832
fstat(3, {st_mode=S_IFREG|0755, st_size=1868984, ...}) = 0
mmap(NULL, 3971488, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x7f82f7310000
...
$ strace df -h
execve("/bin/df", ["df", "-h"], [/* 50 vars */]) = 0
brk(NULL)                               = 0x136e000
access("/etc/ld.so.nohwcap", F_OK)      = -1 ENOENT (No such file or directory)
mmap(NULL, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f82f78fd000
access("/etc/ld.so.preload", R_OK)      = -1 ENOENT (No such file or directory)
open("/etc/ld.so.cache", O_RDONLY|O_CLOEXEC) = 3
fstat(3, {st_mode=S_IFREG|0644, st_size=147662, ...}) = 0
mmap(NULL, 147662, PROT_READ, MAP_PRIVATE, 3, 0) = 0x7f82f78d8000
close(3)                                = 0
access("/etc/ld.so.nohwcap", F_OK)      = -1 ENOENT (No such file or directory)
open("/lib/x86_64-linux-gnu/libc.so.6", O_RDONLY|O_CLOEXEC) = 3
read(3, "\177ELF\2\1\1\3\0\0\0\0\0\0\0\0\3\0>\0\1\0\0\0P\t\2\0\0\0\0\0"..., 832) = 832
fstat(3, {st_mode=S_IFREG|0755, st_size=1868984, ...}) = 0
mmap(NULL, 3971488, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x7f82f7310000
...
$ strace df -h
execve("/bin/df", ["df", "-h"], [/* 50 vars */]) = 0
brk(NULL)                               = 0x136e000
access("/etc/ld.so.nohwcap", F_OK)      = -1 ENOENT (No such file or directory)
mmap(NULL, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f82f78fd000
access("/etc/ld.so.preload", R_OK)      = -1 ENOENT (No such file or directory)
open("/etc/ld.so.cache", O_RDONLY|O_CLOEXEC) = 3
fstat(3, {st_mode=S_IFREG|0644, st_size=147662, ...}) = 0
mmap(NULL, 147662, PROT_READ, MAP_PRIVATE, 3, 0) = 0x7f82f78d8000
close(3)                                = 0
access("/etc/ld.so.nohwcap", F_OK)      = -1 ENOENT (No such file or directory)
open("/lib/x86_64-linux-gnu/libc.so.6", O_RDONLY|O_CLOEXEC) = 3
read(3, "\177ELF\2\1\1\3\0\0\0\0\0\0\0\0\3\0>\0\1\0\0\0P\t\2\0\0\0\0\0"..., 832) = 832
fstat(3, {st_mode=S_IFREG|0755, st_size=1868984, ...}) = 0
mmap(NULL, 3971488, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x7f82f7310000
...
$ strace df -h
execve("/bin/df", ["df", "-h"], [/* 50 vars */]) = 0
brk(NULL)                               = 0x136e000
access("/etc/ld.so.nohwcap", F_OK)      = -1 ENOENT (No such file or directory)
mmap(NULL, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f82f78fd000
access("/etc/ld.so.preload", R_OK)      = -1 ENOENT (No such file or directory)
open("/etc/ld.so.cache", O_RDONLY|O_CLOEXEC) = 3
fstat(3, {st_mode=S_IFREG|0644, st_size=147662, ...}) = 0
mmap(NULL, 147662, PROT_READ, MAP_PRIVATE, 3, 0) = 0x7f82f78d8000
close(3)                                = 0
access("/etc/ld.so.nohwcap", F_OK)      = -1 ENOENT (No such file or directory)
open("/lib/x86_64-linux-gnu/libc.so.6", O_RDONLY|O_CLOEXEC) = 3
read(3, "\177ELF\2\1\1\3\0\0\0\0\0\0\0\0\3\0>\0\1\0\0\0P\t\2\0\0\0\0\0"..., 832) = 832
fstat(3, {st_mode=S_IFREG|0755, st_size=1868984, ...}) = 0
mmap(NULL, 3971488, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x7f82f7310000
...
$ strace df -h
execve("/bin/df", ["df", "-h"], [/* 50 vars */]) = 0
brk(NULL)                               = 0x136e000
access("/etc/ld.so.nohwcap", F_OK)      = -1 ENOENT (No such file or directory)
mmap(NULL, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f82f78fd000
access("/etc/ld.so.preload", R_OK)      = -1 ENOENT (No such file or directory)
open("/etc/ld.so.cache", O_RDONLY|O_CLOEXEC) = 3
fstat(3, {st_mode=S_IFREG|0644, st_size=147662, ...}) = 0
mmap(NULL, 147662, PROT_READ, MAP_PRIVATE, 3, 0) = 0x7f82f78d8000
close(3)                                = 0
access("/etc/ld.so.nohwcap", F_OK)      = -1 ENOENT (No such file or directory)
open("/lib/x86_64-linux-gnu/libc.so.6", O_RDONLY|O_CLOEXEC) = 3
read(3, "\177ELF\2\1\1\3\0\0\0\0\0\0\0\0\3\0>\0\1\0\0\0P\t\2\0\0\0\0\0"..., 832) = 832
fstat(3, {st_mode=S_IFREG|0755, st_size=1868984, ...}) = 0
mmap(NULL, 3971488, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x7f82f7310000
...
$ strace df -h
execve("/bin/df", ["df", "-h"], [/* 50 vars */]) = 0
brk(NULL)                               = 0x136e000
access("/etc/ld.so.nohwcap", F_OK)      = -1 ENOENT (No such file or directory)
mmap(NULL, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f82f78fd000
access("/etc/ld.so.preload", R_OK)      = -1 ENOENT (No such file or directory)
open("/etc/ld.so.cache", O_RDONLY|O_CLOEXEC) = 3
fstat(3, {st_mode=S_IFREG|0644, st_size=147662, ...}) = 0
mmap(NULL, 147662, PROT_READ, MAP_PRIVATE, 3, 0) = 0x7f82f78d8000
close(3)                                = 0
access("/etc/ld.so.nohwcap", F_OK)      = -1 ENOENT (No such file or directory)
open("/lib/x86_64-linux-gnu/libc.so.6", O_RDONLY|O_CLOEXEC) = 3
read(3, "\177ELF\2\1\1\3\0\0\0\0\0\0\0\0\3\0>\0\1\0\0\0P\t\2\0\0\0\0\0"..., 832) = 832
fstat(3, {st_mode=S_IFREG|0755, st_size=1868984, ...}) = 0
mmap(NULL, 3971488, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x7f82f7310000
...

En el resultado anterior, puede ver varios tipos de llamadas al sistema realizadas por el comando df, por ejemplo.

open("/etc/ld.so.cache", O_RDONLY|O_CLOEXEC) = 3

Dónde:

  • abierto: es el tipo de llamada al sistema
  • ("/etc/ld.so.cache", O_RDONLY | O_CLOEXEC) - argumento de llamada al sistema
  • 3 - valor de retorno de la llamada al sistema

A continuación se muestra una salida de muestra que muestra las llamadas al sistema de escritura, que muestra la salida del comando df en la pantalla.

mmap(NULL, 26258, PROT_READ, MAP_SHARED, 3, 0) = 0x7f82f78f5000
close(3)                                = 0
fstat(1, {st_mode=S_IFCHR|0620, st_rdev=makedev(136, 1), ...}) = 0
write(1, "Filesystem      Size  Used Avail"..., 49Filesystem      Size  Used Avail Use% Mounted on
) = 49
write(1, "udev            3.9G     0  3.9G"..., 43udev            3.9G     0  3.9G   0% /dev
) = 43
write(1, "tmpfs           788M  9.6M  779M"..., 43tmpfs           788M  9.6M  779M   2% /run
) = 43
write(1, "/dev/sda10      324G  252G   56G"..., 40/dev/sda10      324G  252G   56G  82% /
) = 40
write(1, "tmpfs           3.9G  104M  3.8G"..., 47tmpfs           3.9G  104M  3.8G   3% /dev/shm
) = 47
write(1, "tmpfs           5.0M  4.0K  5.0M"..., 48tmpfs           5.0M  4.0K  5.0M   1% /run/lock
) = 48
write(1, "tmpfs           3.9G     0  3.9G"..., 53tmpfs           3.9G     0  3.9G   0% /sys/fs/cgroup
) = 53
write(1, "cgmfs           100K     0  100K"..., 56cgmfs           100K     0  100K   0% /run/cgmanager/fs
) = 56
write(1, "tmpfs           788M   36K  788M"..., 53tmpfs           788M   36K  788M   1% /run/user/1000
) = 53
close(1)                                = 0
close(2)                                = 0
exit_group(0)                           = ?
+++ exited with 0 +++

2. Rastrear el PID del proceso de Linux

Si un proceso ya se está ejecutando, puede rastrearlo simplemente pasando su PID de la siguiente manera; esto llenará su pantalla con una salida continua que muestra las llamadas al sistema realizadas por el proceso, para finalizar, presione [Ctrl + C] .

$ sudo strace -p 3569

strace: Process 3569 attached
restart_syscall(<... resuming interrupted poll ...>) = 1
recvmsg(4, {msg_name(0)=NULL, msg_iov(1)=[{"U0!70
$ sudo strace -p 3569
strace: Process 3569 attached
restart_syscall(<... resuming interrupted poll ...>) = 1
recvmsg(4, {msg_name(0)=NULL, msg_iov(1)=[{"U\2\24\300!\247\330\0\3\24\4\0\20\0\0\0\0\0\0\24\24\24\24\24\0\0\3\37%\2\0\0", 4096}], msg_controllen=0, msg_flags=0}, 0) = 32
recvmsg(4, 0x7ffee4dbf870, 0)           = -1 EAGAIN (Resource temporarily unavailable)
recvmsg(4, 0x7ffee4dbf850, 0)           = -1 EAGAIN (Resource temporarily unavailable)
poll([{fd=3, events=POLLIN}, {fd=4, events=POLLIN}, {fd=5, events=POLLIN}, {fd=10, events=POLLIN}, {fd=30, events=POLLIN}, {fd=31, events=POLLIN}], 6, -1) = 1 ([{fd=31, revents=POLLIN}])
read(31, "\372", 1)                     = 1
recvmsg(4, 0x7ffee4dbf850, 0)           = -1 EAGAIN (Resource temporarily unavailable)
poll([{fd=3, events=POLLIN}, {fd=4, events=POLLIN}, {fd=5, events=POLLIN}, {fd=10, events=POLLIN}, {fd=30, events=POLLIN}, {fd=31, events=POLLIN}], 6, 0) = 1 ([{fd=31, revents=POLLIN}])
read(31, "\372", 1)                     = 1
recvmsg(4, 0x7ffee4dbf850, 0)           = -1 EAGAIN (Resource temporarily unavailable)
poll([{fd=3, events=POLLIN}, {fd=4, events=POLLIN}, {fd=5, events=POLLIN}, {fd=10, events=POLLIN}, {fd=30, events=POLLIN}, {fd=31, events=POLLIN}], 6, 0) = 0 (Timeout)
mprotect(0x207faa20000, 8192, PROT_READ|PROT_WRITE) = 0
mprotect(0x207faa20000, 8192, PROT_READ|PROT_EXEC) = 0
mprotect(0x207faa21000, 4096, PROT_READ|PROT_WRITE) = 0
mprotect(0x207faa21000, 4096, PROT_READ|PROT_EXEC) = 0
...
$ sudo strace -p 3569
strace: Process 3569 attached
restart_syscall(<... resuming interrupted poll ...>) = 1
recvmsg(4, {msg_name(0)=NULL, msg_iov(1)=[{"U\2\24\300!\247\330\0\3\24\4\0\20\0\0\0\0\0\0\24\24\24\24\24\0\0\3\37%\2\0\0", 4096}], msg_controllen=0, msg_flags=0}, 0) = 32
recvmsg(4, 0x7ffee4dbf870, 0)           = -1 EAGAIN (Resource temporarily unavailable)
recvmsg(4, 0x7ffee4dbf850, 0)           = -1 EAGAIN (Resource temporarily unavailable)
poll([{fd=3, events=POLLIN}, {fd=4, events=POLLIN}, {fd=5, events=POLLIN}, {fd=10, events=POLLIN}, {fd=30, events=POLLIN}, {fd=31, events=POLLIN}], 6, -1) = 1 ([{fd=31, revents=POLLIN}])
read(31, "\372", 1)                     = 1
recvmsg(4, 0x7ffee4dbf850, 0)           = -1 EAGAIN (Resource temporarily unavailable)
poll([{fd=3, events=POLLIN}, {fd=4, events=POLLIN}, {fd=5, events=POLLIN}, {fd=10, events=POLLIN}, {fd=30, events=POLLIN}, {fd=31, events=POLLIN}], 6, 0) = 1 ([{fd=31, revents=POLLIN}])
read(31, "\372", 1)                     = 1
recvmsg(4, 0x7ffee4dbf850, 0)           = -1 EAGAIN (Resource temporarily unavailable)
poll([{fd=3, events=POLLIN}, {fd=4, events=POLLIN}, {fd=5, events=POLLIN}, {fd=10, events=POLLIN}, {fd=30, events=POLLIN}, {fd=31, events=POLLIN}], 6, 0) = 0 (Timeout)
mprotect(0x207faa20000, 8192, PROT_READ|PROT_WRITE) = 0
mprotect(0x207faa20000, 8192, PROT_READ|PROT_EXEC) = 0
mprotect(0x207faa21000, 4096, PROT_READ|PROT_WRITE) = 0
mprotect(0x207faa21000, 4096, PROT_READ|PROT_EXEC) = 0
...
$ sudo strace -p 3569
strace: Process 3569 attached
restart_syscall(<... resuming interrupted poll ...>) = 1
recvmsg(4, {msg_name(0)=NULL, msg_iov(1)=[{"U\2\24\300!\247\330\0\3\24\4\0\20\0\0\0\0\0\0\24\24\24\24\24\0\0\3\37%\2\0\0", 4096}], msg_controllen=0, msg_flags=0}, 0) = 32
recvmsg(4, 0x7ffee4dbf870, 0)           = -1 EAGAIN (Resource temporarily unavailable)
recvmsg(4, 0x7ffee4dbf850, 0)           = -1 EAGAIN (Resource temporarily unavailable)
poll([{fd=3, events=POLLIN}, {fd=4, events=POLLIN}, {fd=5, events=POLLIN}, {fd=10, events=POLLIN}, {fd=30, events=POLLIN}, {fd=31, events=POLLIN}], 6, -1) = 1 ([{fd=31, revents=POLLIN}])
read(31, "\372", 1)                     = 1
recvmsg(4, 0x7ffee4dbf850, 0)           = -1 EAGAIN (Resource temporarily unavailable)
poll([{fd=3, events=POLLIN}, {fd=4, events=POLLIN}, {fd=5, events=POLLIN}, {fd=10, events=POLLIN}, {fd=30, events=POLLIN}, {fd=31, events=POLLIN}], 6, 0) = 1 ([{fd=31, revents=POLLIN}])
read(31, "\372", 1)                     = 1
recvmsg(4, 0x7ffee4dbf850, 0)           = -1 EAGAIN (Resource temporarily unavailable)
poll([{fd=3, events=POLLIN}, {fd=4, events=POLLIN}, {fd=5, events=POLLIN}, {fd=10, events=POLLIN}, {fd=30, events=POLLIN}, {fd=31, events=POLLIN}], 6, 0) = 0 (Timeout)
mprotect(0x207faa20000, 8192, PROT_READ|PROT_WRITE) = 0
mprotect(0x207faa20000, 8192, PROT_READ|PROT_EXEC) = 0
mprotect(0x207faa21000, 4096, PROT_READ|PROT_WRITE) = 0
mprotect(0x207faa21000, 4096, PROT_READ|PROT_EXEC) = 0
...
$ sudo strace -p 3569
strace: Process 3569 attached
restart_syscall(<... resuming interrupted poll ...>) = 1
recvmsg(4, {msg_name(0)=NULL, msg_iov(1)=[{"U\2\24\300!\247\330\0\3\24\4\0\20\0\0\0\0\0\0\24\24\24\24\24\0\0\3\37%\2\0\0", 4096}], msg_controllen=0, msg_flags=0}, 0) = 32
recvmsg(4, 0x7ffee4dbf870, 0)           = -1 EAGAIN (Resource temporarily unavailable)
recvmsg(4, 0x7ffee4dbf850, 0)           = -1 EAGAIN (Resource temporarily unavailable)
poll([{fd=3, events=POLLIN}, {fd=4, events=POLLIN}, {fd=5, events=POLLIN}, {fd=10, events=POLLIN}, {fd=30, events=POLLIN}, {fd=31, events=POLLIN}], 6, -1) = 1 ([{fd=31, revents=POLLIN}])
read(31, "\372", 1)                     = 1
recvmsg(4, 0x7ffee4dbf850, 0)           = -1 EAGAIN (Resource temporarily unavailable)
poll([{fd=3, events=POLLIN}, {fd=4, events=POLLIN}, {fd=5, events=POLLIN}, {fd=10, events=POLLIN}, {fd=30, events=POLLIN}, {fd=31, events=POLLIN}], 6, 0) = 1 ([{fd=31, revents=POLLIN}])
read(31, "\372", 1)                     = 1
recvmsg(4, 0x7ffee4dbf850, 0)           = -1 EAGAIN (Resource temporarily unavailable)
poll([{fd=3, events=POLLIN}, {fd=4, events=POLLIN}, {fd=5, events=POLLIN}, {fd=10, events=POLLIN}, {fd=30, events=POLLIN}, {fd=31, events=POLLIN}], 6, 0) = 0 (Timeout)
mprotect(0x207faa20000, 8192, PROT_READ|PROT_WRITE) = 0
mprotect(0x207faa20000, 8192, PROT_READ|PROT_EXEC) = 0
mprotect(0x207faa21000, 4096, PROT_READ|PROT_WRITE) = 0
mprotect(0x207faa21000, 4096, PROT_READ|PROT_EXEC) = 0
...
$ sudo strace -p 3569
strace: Process 3569 attached
restart_syscall(<... resuming interrupted poll ...>) = 1
recvmsg(4, {msg_name(0)=NULL, msg_iov(1)=[{"U\2\24\300!\247\330\0\3\24\4\0\20\0\0\0\0\0\0\24\24\24\24\24\0\0\3\37%\2\0\0", 4096}], msg_controllen=0, msg_flags=0}, 0) = 32
recvmsg(4, 0x7ffee4dbf870, 0)           = -1 EAGAIN (Resource temporarily unavailable)
recvmsg(4, 0x7ffee4dbf850, 0)           = -1 EAGAIN (Resource temporarily unavailable)
poll([{fd=3, events=POLLIN}, {fd=4, events=POLLIN}, {fd=5, events=POLLIN}, {fd=10, events=POLLIN}, {fd=30, events=POLLIN}, {fd=31, events=POLLIN}], 6, -1) = 1 ([{fd=31, revents=POLLIN}])
read(31, "\372", 1)                     = 1
recvmsg(4, 0x7ffee4dbf850, 0)           = -1 EAGAIN (Resource temporarily unavailable)
poll([{fd=3, events=POLLIN}, {fd=4, events=POLLIN}, {fd=5, events=POLLIN}, {fd=10, events=POLLIN}, {fd=30, events=POLLIN}, {fd=31, events=POLLIN}], 6, 0) = 1 ([{fd=31, revents=POLLIN}])
read(31, "\372", 1)                     = 1
recvmsg(4, 0x7ffee4dbf850, 0)           = -1 EAGAIN (Resource temporarily unavailable)
poll([{fd=3, events=POLLIN}, {fd=4, events=POLLIN}, {fd=5, events=POLLIN}, {fd=10, events=POLLIN}, {fd=30, events=POLLIN}, {fd=31, events=POLLIN}], 6, 0) = 0 (Timeout)
mprotect(0x207faa20000, 8192, PROT_READ|PROT_WRITE) = 0
mprotect(0x207faa20000, 8192, PROT_READ|PROT_EXEC) = 0
mprotect(0x207faa21000, 4096, PROT_READ|PROT_WRITE) = 0
mprotect(0x207faa21000, 4096, PROT_READ|PROT_EXEC) = 0
...
$ sudo strace -p 3569
strace: Process 3569 attached
restart_syscall(<... resuming interrupted poll ...>) = 1
recvmsg(4, {msg_name(0)=NULL, msg_iov(1)=[{"U\2\24\300!\247\330\0\3\24\4\0\20\0\0\0\0\0\0\24\24\24\24\24\0\0\3\37%\2\0\0", 4096}], msg_controllen=0, msg_flags=0}, 0) = 32
recvmsg(4, 0x7ffee4dbf870, 0)           = -1 EAGAIN (Resource temporarily unavailable)
recvmsg(4, 0x7ffee4dbf850, 0)           = -1 EAGAIN (Resource temporarily unavailable)
poll([{fd=3, events=POLLIN}, {fd=4, events=POLLIN}, {fd=5, events=POLLIN}, {fd=10, events=POLLIN}, {fd=30, events=POLLIN}, {fd=31, events=POLLIN}], 6, -1) = 1 ([{fd=31, revents=POLLIN}])
read(31, "\372", 1)                     = 1
recvmsg(4, 0x7ffee4dbf850, 0)           = -1 EAGAIN (Resource temporarily unavailable)
poll([{fd=3, events=POLLIN}, {fd=4, events=POLLIN}, {fd=5, events=POLLIN}, {fd=10, events=POLLIN}, {fd=30, events=POLLIN}, {fd=31, events=POLLIN}], 6, 0) = 1 ([{fd=31, revents=POLLIN}])
read(31, "\372", 1)                     = 1
recvmsg(4, 0x7ffee4dbf850, 0)           = -1 EAGAIN (Resource temporarily unavailable)
poll([{fd=3, events=POLLIN}, {fd=4, events=POLLIN}, {fd=5, events=POLLIN}, {fd=10, events=POLLIN}, {fd=30, events=POLLIN}, {fd=31, events=POLLIN}], 6, 0) = 0 (Timeout)
mprotect(0x207faa20000, 8192, PROT_READ|PROT_WRITE) = 0
mprotect(0x207faa20000, 8192, PROT_READ|PROT_EXEC) = 0
mprotect(0x207faa21000, 4096, PROT_READ|PROT_WRITE) = 0
mprotect(0x207faa21000, 4096, PROT_READ|PROT_EXEC) = 0
...
$ sudo strace -p 3569
strace: Process 3569 attached
restart_syscall(<... resuming interrupted poll ...>) = 1
recvmsg(4, {msg_name(0)=NULL, msg_iov(1)=[{"U\2\24\300!\247\330\0\3\24\4\0\20\0\0\0\0\0\0\24\24\24\24\24\0\0\3\37%\2\0\0", 4096}], msg_controllen=0, msg_flags=0}, 0) = 32
recvmsg(4, 0x7ffee4dbf870, 0)           = -1 EAGAIN (Resource temporarily unavailable)
recvmsg(4, 0x7ffee4dbf850, 0)           = -1 EAGAIN (Resource temporarily unavailable)
poll([{fd=3, events=POLLIN}, {fd=4, events=POLLIN}, {fd=5, events=POLLIN}, {fd=10, events=POLLIN}, {fd=30, events=POLLIN}, {fd=31, events=POLLIN}], 6, -1) = 1 ([{fd=31, revents=POLLIN}])
read(31, "\372", 1)                     = 1
recvmsg(4, 0x7ffee4dbf850, 0)           = -1 EAGAIN (Resource temporarily unavailable)
poll([{fd=3, events=POLLIN}, {fd=4, events=POLLIN}, {fd=5, events=POLLIN}, {fd=10, events=POLLIN}, {fd=30, events=POLLIN}, {fd=31, events=POLLIN}], 6, 0) = 1 ([{fd=31, revents=POLLIN}])
read(31, "\372", 1)                     = 1
recvmsg(4, 0x7ffee4dbf850, 0)           = -1 EAGAIN (Resource temporarily unavailable)
poll([{fd=3, events=POLLIN}, {fd=4, events=POLLIN}, {fd=5, events=POLLIN}, {fd=10, events=POLLIN}, {fd=30, events=POLLIN}, {fd=31, events=POLLIN}], 6, 0) = 0 (Timeout)
mprotect(0x207faa20000, 8192, PROT_READ|PROT_WRITE) = 0
mprotect(0x207faa20000, 8192, PROT_READ|PROT_EXEC) = 0
mprotect(0x207faa21000, 4096, PROT_READ|PROT_WRITE) = 0
mprotect(0x207faa21000, 4096, PROT_READ|PROT_EXEC) = 0
...
$ sudo strace -p 3569
strace: Process 3569 attached
restart_syscall(<... resuming interrupted poll ...>) = 1
recvmsg(4, {msg_name(0)=NULL, msg_iov(1)=[{"U\2\24\300!\247\330\0\3\24\4\0\20\0\0\0\0\0\0\24\24\24\24\24\0\0\3\37%\2\0\0", 4096}], msg_controllen=0, msg_flags=0}, 0) = 32
recvmsg(4, 0x7ffee4dbf870, 0)           = -1 EAGAIN (Resource temporarily unavailable)
recvmsg(4, 0x7ffee4dbf850, 0)           = -1 EAGAIN (Resource temporarily unavailable)
poll([{fd=3, events=POLLIN}, {fd=4, events=POLLIN}, {fd=5, events=POLLIN}, {fd=10, events=POLLIN}, {fd=30, events=POLLIN}, {fd=31, events=POLLIN}], 6, -1) = 1 ([{fd=31, revents=POLLIN}])
read(31, "\372", 1)                     = 1
recvmsg(4, 0x7ffee4dbf850, 0)           = -1 EAGAIN (Resource temporarily unavailable)
poll([{fd=3, events=POLLIN}, {fd=4, events=POLLIN}, {fd=5, events=POLLIN}, {fd=10, events=POLLIN}, {fd=30, events=POLLIN}, {fd=31, events=POLLIN}], 6, 0) = 1 ([{fd=31, revents=POLLIN}])
read(31, "\372", 1)                     = 1
recvmsg(4, 0x7ffee4dbf850, 0)           = -1 EAGAIN (Resource temporarily unavailable)
poll([{fd=3, events=POLLIN}, {fd=4, events=POLLIN}, {fd=5, events=POLLIN}, {fd=10, events=POLLIN}, {fd=30, events=POLLIN}, {fd=31, events=POLLIN}], 6, 0) = 0 (Timeout)
mprotect(0x207faa20000, 8192, PROT_READ|PROT_WRITE) = 0
mprotect(0x207faa20000, 8192, PROT_READ|PROT_EXEC) = 0
mprotect(0x207faa21000, 4096, PROT_READ|PROT_WRITE) = 0
mprotect(0x207faa21000, 4096, PROT_READ|PROT_EXEC) = 0
...
$ sudo strace -p 3569
strace: Process 3569 attached
restart_syscall(<... resuming interrupted poll ...>) = 1
recvmsg(4, {msg_name(0)=NULL, msg_iov(1)=[{"U\2\24\300!\247\330\0\3\24\4\0\20\0\0\0\0\0\0\24\24\24\24\24\0\0\3\37%\2\0\0", 4096}], msg_controllen=0, msg_flags=0}, 0) = 32
recvmsg(4, 0x7ffee4dbf870, 0)           = -1 EAGAIN (Resource temporarily unavailable)
recvmsg(4, 0x7ffee4dbf850, 0)           = -1 EAGAIN (Resource temporarily unavailable)
poll([{fd=3, events=POLLIN}, {fd=4, events=POLLIN}, {fd=5, events=POLLIN}, {fd=10, events=POLLIN}, {fd=30, events=POLLIN}, {fd=31, events=POLLIN}], 6, -1) = 1 ([{fd=31, revents=POLLIN}])
read(31, "\372", 1)                     = 1
recvmsg(4, 0x7ffee4dbf850, 0)           = -1 EAGAIN (Resource temporarily unavailable)
poll([{fd=3, events=POLLIN}, {fd=4, events=POLLIN}, {fd=5, events=POLLIN}, {fd=10, events=POLLIN}, {fd=30, events=POLLIN}, {fd=31, events=POLLIN}], 6, 0) = 1 ([{fd=31, revents=POLLIN}])
read(31, "\372", 1)                     = 1
recvmsg(4, 0x7ffee4dbf850, 0)           = -1 EAGAIN (Resource temporarily unavailable)
poll([{fd=3, events=POLLIN}, {fd=4, events=POLLIN}, {fd=5, events=POLLIN}, {fd=10, events=POLLIN}, {fd=30, events=POLLIN}, {fd=31, events=POLLIN}], 6, 0) = 0 (Timeout)
mprotect(0x207faa20000, 8192, PROT_READ|PROT_WRITE) = 0
mprotect(0x207faa20000, 8192, PROT_READ|PROT_EXEC) = 0
mprotect(0x207faa21000, 4096, PROT_READ|PROT_WRITE) = 0
mprotect(0x207faa21000, 4096, PROT_READ|PROT_EXEC) = 0
...
$ sudo strace -p 3569
strace: Process 3569 attached
restart_syscall(<... resuming interrupted poll ...>) = 1
recvmsg(4, {msg_name(0)=NULL, msg_iov(1)=[{"U\2\24\300!\247\330\0\3\24\4\0\20\0\0\0\0\0\0\24\24\24\24\24\0\0\3\37%\2\0\0", 4096}], msg_controllen=0, msg_flags=0}, 0) = 32
recvmsg(4, 0x7ffee4dbf870, 0)           = -1 EAGAIN (Resource temporarily unavailable)
recvmsg(4, 0x7ffee4dbf850, 0)           = -1 EAGAIN (Resource temporarily unavailable)
poll([{fd=3, events=POLLIN}, {fd=4, events=POLLIN}, {fd=5, events=POLLIN}, {fd=10, events=POLLIN}, {fd=30, events=POLLIN}, {fd=31, events=POLLIN}], 6, -1) = 1 ([{fd=31, revents=POLLIN}])
read(31, "\372", 1)                     = 1
recvmsg(4, 0x7ffee4dbf850, 0)           = -1 EAGAIN (Resource temporarily unavailable)
poll([{fd=3, events=POLLIN}, {fd=4, events=POLLIN}, {fd=5, events=POLLIN}, {fd=10, events=POLLIN}, {fd=30, events=POLLIN}, {fd=31, events=POLLIN}], 6, 0) = 1 ([{fd=31, revents=POLLIN}])
read(31, "\372", 1)                     = 1
recvmsg(4, 0x7ffee4dbf850, 0)           = -1 EAGAIN (Resource temporarily unavailable)
poll([{fd=3, events=POLLIN}, {fd=4, events=POLLIN}, {fd=5, events=POLLIN}, {fd=10, events=POLLIN}, {fd=30, events=POLLIN}, {fd=31, events=POLLIN}], 6, 0) = 0 (Timeout)
mprotect(0x207faa20000, 8192, PROT_READ|PROT_WRITE) = 0
mprotect(0x207faa20000, 8192, PROT_READ|PROT_EXEC) = 0
mprotect(0x207faa21000, 4096, PROT_READ|PROT_WRITE) = 0
mprotect(0x207faa21000, 4096, PROT_READ|PROT_EXEC) = 0
...
$ sudo strace -p 3569
strace: Process 3569 attached
restart_syscall(<... resuming interrupted poll ...>) = 1
recvmsg(4, {msg_name(0)=NULL, msg_iov(1)=[{"U\2\24\300!\247\330\0\3\24\4\0\20\0\0\0\0\0\0\24\24\24\24\24\0\0\3\37%\2\0\0", 4096}], msg_controllen=0, msg_flags=0}, 0) = 32
recvmsg(4, 0x7ffee4dbf870, 0)           = -1 EAGAIN (Resource temporarily unavailable)
recvmsg(4, 0x7ffee4dbf850, 0)           = -1 EAGAIN (Resource temporarily unavailable)
poll([{fd=3, events=POLLIN}, {fd=4, events=POLLIN}, {fd=5, events=POLLIN}, {fd=10, events=POLLIN}, {fd=30, events=POLLIN}, {fd=31, events=POLLIN}], 6, -1) = 1 ([{fd=31, revents=POLLIN}])
read(31, "\372", 1)                     = 1
recvmsg(4, 0x7ffee4dbf850, 0)           = -1 EAGAIN (Resource temporarily unavailable)
poll([{fd=3, events=POLLIN}, {fd=4, events=POLLIN}, {fd=5, events=POLLIN}, {fd=10, events=POLLIN}, {fd=30, events=POLLIN}, {fd=31, events=POLLIN}], 6, 0) = 1 ([{fd=31, revents=POLLIN}])
read(31, "\372", 1)                     = 1
recvmsg(4, 0x7ffee4dbf850, 0)           = -1 EAGAIN (Resource temporarily unavailable)
poll([{fd=3, events=POLLIN}, {fd=4, events=POLLIN}, {fd=5, events=POLLIN}, {fd=10, events=POLLIN}, {fd=30, events=POLLIN}, {fd=31, events=POLLIN}], 6, 0) = 0 (Timeout)
mprotect(0x207faa20000, 8192, PROT_READ|PROT_WRITE) = 0
mprotect(0x207faa20000, 8192, PROT_READ|PROT_EXEC) = 0
mprotect(0x207faa21000, 4096, PROT_READ|PROT_WRITE) = 0
mprotect(0x207faa21000, 4096, PROT_READ|PROT_EXEC) = 0
...
$ sudo strace -p 3569
strace: Process 3569 attached
restart_syscall(<... resuming interrupted poll ...>) = 1
recvmsg(4, {msg_name(0)=NULL, msg_iov(1)=[{"U\2\24\300!\247\330\0\3\24\4\0\20\0\0\0\0\0\0\24\24\24\24\24\0\0\3\37%\2\0\0", 4096}], msg_controllen=0, msg_flags=0}, 0) = 32
recvmsg(4, 0x7ffee4dbf870, 0)           = -1 EAGAIN (Resource temporarily unavailable)
recvmsg(4, 0x7ffee4dbf850, 0)           = -1 EAGAIN (Resource temporarily unavailable)
poll([{fd=3, events=POLLIN}, {fd=4, events=POLLIN}, {fd=5, events=POLLIN}, {fd=10, events=POLLIN}, {fd=30, events=POLLIN}, {fd=31, events=POLLIN}], 6, -1) = 1 ([{fd=31, revents=POLLIN}])
read(31, "\372", 1)                     = 1
recvmsg(4, 0x7ffee4dbf850, 0)           = -1 EAGAIN (Resource temporarily unavailable)
poll([{fd=3, events=POLLIN}, {fd=4, events=POLLIN}, {fd=5, events=POLLIN}, {fd=10, events=POLLIN}, {fd=30, events=POLLIN}, {fd=31, events=POLLIN}], 6, 0) = 1 ([{fd=31, revents=POLLIN}])
read(31, "\372", 1)                     = 1
recvmsg(4, 0x7ffee4dbf850, 0)           = -1 EAGAIN (Resource temporarily unavailable)
poll([{fd=3, events=POLLIN}, {fd=4, events=POLLIN}, {fd=5, events=POLLIN}, {fd=10, events=POLLIN}, {fd=30, events=POLLIN}, {fd=31, events=POLLIN}], 6, 0) = 0 (Timeout)
mprotect(0x207faa20000, 8192, PROT_READ|PROT_WRITE) = 0
mprotect(0x207faa20000, 8192, PROT_READ|PROT_EXEC) = 0
mprotect(0x207faa21000, 4096, PROT_READ|PROT_WRITE) = 0
mprotect(0x207faa21000, 4096, PROT_READ|PROT_EXEC) = 0
...

3. Obtenga un resumen del proceso de Linux

Con el indicador -c , puede generar un informe del tiempo total, las llamadas y los errores para cada llamada al sistema, de la siguiente manera.

$ sudo strace -c -p 3569

strace: Process 3569 attached

^Cstrace: Process 3569 detached
% time     seconds  usecs/call     calls    errors syscall
------ ----------- ----------- --------- --------- ----------------
 99.73    0.016000           8      1971           poll
  0.16    0.000025           0       509        75 futex
  0.06    0.000010           0      1985      1966 recvmsg
  0.06    0.000009           0      2336           mprotect
  0.00    0.000000           0       478           read
  0.00    0.000000           0        13           write
  0.00    0.000000           0        29           mmap
  0.00    0.000000           0         9           munmap
  0.00    0.000000           0        18           writev
  0.00    0.000000           0       351           madvise
  0.00    0.000000           0         1           restart_syscall
------ ----------- ----------- --------- --------- ----------------
100.00    0.016044                  7700      2041 total

4. Imprimir puntero de instrucción durante la llamada al sistema

La opción -i muestra el puntero de instrucción en el momento de cada llamada al sistema realizada por el programa.

$ sudo strace -i df -h

[00007f0d7534c777] execve("/bin/df", ["df", "-h"], [/* 17 vars */]) = 0
[00007faf9cafa4b9] brk(NULL)            = 0x12f0000
[00007faf9cafb387] access("/etc/ld.so.nohwcap", F_OK) = -1 ENOENT (No such file or directory)
[00007faf9cafb47a] mmap(NULL, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7faf9cd03000
[00007faf9cafb387] access("/etc/ld.so.preload", R_OK) = -1 ENOENT (No such file or directory)
[00007faf9cafb327] open("/etc/ld.so.cache", O_RDONLY|O_CLOEXEC) = 3
[00007faf9cafb2b4] fstat(3, {st_mode=S_IFREG|0644, st_size=147662, ...}) = 0
[00007faf9cafb47a] mmap(NULL, 147662, PROT_READ, MAP_PRIVATE, 3, 0) = 0x7faf9ccde000
[00007faf9cafb427] close(3)             = 0
[00007faf9cafb387] access("/etc/ld.so.nohwcap", F_OK) = -1 ENOENT (No such file or directory)
[00007faf9cafb327] open("/lib/x86_64-linux-gnu/libc.so.6", O_RDONLY|O_CLOEXEC) = 3
[00007faf9cafb347] read(3, "7ELF
$ sudo strace -i df -h
[00007f0d7534c777] execve("/bin/df", ["df", "-h"], [/* 17 vars */]) = 0
[00007faf9cafa4b9] brk(NULL)            = 0x12f0000
[00007faf9cafb387] access("/etc/ld.so.nohwcap", F_OK) = -1 ENOENT (No such file or directory)
[00007faf9cafb47a] mmap(NULL, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7faf9cd03000
[00007faf9cafb387] access("/etc/ld.so.preload", R_OK) = -1 ENOENT (No such file or directory)
[00007faf9cafb327] open("/etc/ld.so.cache", O_RDONLY|O_CLOEXEC) = 3
[00007faf9cafb2b4] fstat(3, {st_mode=S_IFREG|0644, st_size=147662, ...}) = 0
[00007faf9cafb47a] mmap(NULL, 147662, PROT_READ, MAP_PRIVATE, 3, 0) = 0x7faf9ccde000
[00007faf9cafb427] close(3)             = 0
[00007faf9cafb387] access("/etc/ld.so.nohwcap", F_OK) = -1 ENOENT (No such file or directory)
[00007faf9cafb327] open("/lib/x86_64-linux-gnu/libc.so.6", O_RDONLY|O_CLOEXEC) = 3
[00007faf9cafb347] read(3, "\177ELF\2\1\1\3\0\0\0\0\0\0\0\0\3\0>\0\1\0\0\0P\t\2\0\0\0\0\0"..., 832) = 832
[00007faf9cafb2b4] fstat(3, {st_mode=S_IFREG|0755, st_size=1868984, ...}) = 0
[00007faf9cafb47a] mmap(NULL, 3971488, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x7faf9c716000
[00007faf9cafb517] mprotect(0x7faf9c8d6000, 2097152, PROT_NONE) = 0
...
$ sudo strace -i df -h
[00007f0d7534c777] execve("/bin/df", ["df", "-h"], [/* 17 vars */]) = 0
[00007faf9cafa4b9] brk(NULL)            = 0x12f0000
[00007faf9cafb387] access("/etc/ld.so.nohwcap", F_OK) = -1 ENOENT (No such file or directory)
[00007faf9cafb47a] mmap(NULL, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7faf9cd03000
[00007faf9cafb387] access("/etc/ld.so.preload", R_OK) = -1 ENOENT (No such file or directory)
[00007faf9cafb327] open("/etc/ld.so.cache", O_RDONLY|O_CLOEXEC) = 3
[00007faf9cafb2b4] fstat(3, {st_mode=S_IFREG|0644, st_size=147662, ...}) = 0
[00007faf9cafb47a] mmap(NULL, 147662, PROT_READ, MAP_PRIVATE, 3, 0) = 0x7faf9ccde000
[00007faf9cafb427] close(3)             = 0
[00007faf9cafb387] access("/etc/ld.so.nohwcap", F_OK) = -1 ENOENT (No such file or directory)
[00007faf9cafb327] open("/lib/x86_64-linux-gnu/libc.so.6", O_RDONLY|O_CLOEXEC) = 3
[00007faf9cafb347] read(3, "\177ELF\2\1\1\3\0\0\0\0\0\0\0\0\3\0>\0\1\0\0\0P\t\2\0\0\0\0\0"..., 832) = 832
[00007faf9cafb2b4] fstat(3, {st_mode=S_IFREG|0755, st_size=1868984, ...}) = 0
[00007faf9cafb47a] mmap(NULL, 3971488, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x7faf9c716000
[00007faf9cafb517] mprotect(0x7faf9c8d6000, 2097152, PROT_NONE) = 0
...
$ sudo strace -i df -h
[00007f0d7534c777] execve("/bin/df", ["df", "-h"], [/* 17 vars */]) = 0
[00007faf9cafa4b9] brk(NULL)            = 0x12f0000
[00007faf9cafb387] access("/etc/ld.so.nohwcap", F_OK) = -1 ENOENT (No such file or directory)
[00007faf9cafb47a] mmap(NULL, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7faf9cd03000
[00007faf9cafb387] access("/etc/ld.so.preload", R_OK) = -1 ENOENT (No such file or directory)
[00007faf9cafb327] open("/etc/ld.so.cache", O_RDONLY|O_CLOEXEC) = 3
[00007faf9cafb2b4] fstat(3, {st_mode=S_IFREG|0644, st_size=147662, ...}) = 0
[00007faf9cafb47a] mmap(NULL, 147662, PROT_READ, MAP_PRIVATE, 3, 0) = 0x7faf9ccde000
[00007faf9cafb427] close(3)             = 0
[00007faf9cafb387] access("/etc/ld.so.nohwcap", F_OK) = -1 ENOENT (No such file or directory)
[00007faf9cafb327] open("/lib/x86_64-linux-gnu/libc.so.6", O_RDONLY|O_CLOEXEC) = 3
[00007faf9cafb347] read(3, "\177ELF\2\1\1\3\0\0\0\0\0\0\0\0\3\0>\0\1\0\0\0P\t\2\0\0\0\0\0"..., 832) = 832
[00007faf9cafb2b4] fstat(3, {st_mode=S_IFREG|0755, st_size=1868984, ...}) = 0
[00007faf9cafb47a] mmap(NULL, 3971488, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x7faf9c716000
[00007faf9cafb517] mprotect(0x7faf9c8d6000, 2097152, PROT_NONE) = 0
...
$ sudo strace -i df -h
[00007f0d7534c777] execve("/bin/df", ["df", "-h"], [/* 17 vars */]) = 0
[00007faf9cafa4b9] brk(NULL)            = 0x12f0000
[00007faf9cafb387] access("/etc/ld.so.nohwcap", F_OK) = -1 ENOENT (No such file or directory)
[00007faf9cafb47a] mmap(NULL, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7faf9cd03000
[00007faf9cafb387] access("/etc/ld.so.preload", R_OK) = -1 ENOENT (No such file or directory)
[00007faf9cafb327] open("/etc/ld.so.cache", O_RDONLY|O_CLOEXEC) = 3
[00007faf9cafb2b4] fstat(3, {st_mode=S_IFREG|0644, st_size=147662, ...}) = 0
[00007faf9cafb47a] mmap(NULL, 147662, PROT_READ, MAP_PRIVATE, 3, 0) = 0x7faf9ccde000
[00007faf9cafb427] close(3)             = 0
[00007faf9cafb387] access("/etc/ld.so.nohwcap", F_OK) = -1 ENOENT (No such file or directory)
[00007faf9cafb327] open("/lib/x86_64-linux-gnu/libc.so.6", O_RDONLY|O_CLOEXEC) = 3
[00007faf9cafb347] read(3, "\177ELF\2\1\1\3\0\0\0\0\0\0\0\0\3\0>\0\1\0\0\0P\t\2\0\0\0\0\0"..., 832) = 832
[00007faf9cafb2b4] fstat(3, {st_mode=S_IFREG|0755, st_size=1868984, ...}) = 0
[00007faf9cafb47a] mmap(NULL, 3971488, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x7faf9c716000
[00007faf9cafb517] mprotect(0x7faf9c8d6000, 2097152, PROT_NONE) = 0
...
$ sudo strace -i df -h
[00007f0d7534c777] execve("/bin/df", ["df", "-h"], [/* 17 vars */]) = 0
[00007faf9cafa4b9] brk(NULL)            = 0x12f0000
[00007faf9cafb387] access("/etc/ld.so.nohwcap", F_OK) = -1 ENOENT (No such file or directory)
[00007faf9cafb47a] mmap(NULL, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7faf9cd03000
[00007faf9cafb387] access("/etc/ld.so.preload", R_OK) = -1 ENOENT (No such file or directory)
[00007faf9cafb327] open("/etc/ld.so.cache", O_RDONLY|O_CLOEXEC) = 3
[00007faf9cafb2b4] fstat(3, {st_mode=S_IFREG|0644, st_size=147662, ...}) = 0
[00007faf9cafb47a] mmap(NULL, 147662, PROT_READ, MAP_PRIVATE, 3, 0) = 0x7faf9ccde000
[00007faf9cafb427] close(3)             = 0
[00007faf9cafb387] access("/etc/ld.so.nohwcap", F_OK) = -1 ENOENT (No such file or directory)
[00007faf9cafb327] open("/lib/x86_64-linux-gnu/libc.so.6", O_RDONLY|O_CLOEXEC) = 3
[00007faf9cafb347] read(3, "\177ELF\2\1\1\3\0\0\0\0\0\0\0\0\3\0>\0\1\0\0\0P\t\2\0\0\0\0\0"..., 832) = 832
[00007faf9cafb2b4] fstat(3, {st_mode=S_IFREG|0755, st_size=1868984, ...}) = 0
[00007faf9cafb47a] mmap(NULL, 3971488, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x7faf9c716000
[00007faf9cafb517] mprotect(0x7faf9c8d6000, 2097152, PROT_NONE) = 0
...
$ sudo strace -i df -h
[00007f0d7534c777] execve("/bin/df", ["df", "-h"], [/* 17 vars */]) = 0
[00007faf9cafa4b9] brk(NULL)            = 0x12f0000
[00007faf9cafb387] access("/etc/ld.so.nohwcap", F_OK) = -1 ENOENT (No such file or directory)
[00007faf9cafb47a] mmap(NULL, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7faf9cd03000
[00007faf9cafb387] access("/etc/ld.so.preload", R_OK) = -1 ENOENT (No such file or directory)
[00007faf9cafb327] open("/etc/ld.so.cache", O_RDONLY|O_CLOEXEC) = 3
[00007faf9cafb2b4] fstat(3, {st_mode=S_IFREG|0644, st_size=147662, ...}) = 0
[00007faf9cafb47a] mmap(NULL, 147662, PROT_READ, MAP_PRIVATE, 3, 0) = 0x7faf9ccde000
[00007faf9cafb427] close(3)             = 0
[00007faf9cafb387] access("/etc/ld.so.nohwcap", F_OK) = -1 ENOENT (No such file or directory)
[00007faf9cafb327] open("/lib/x86_64-linux-gnu/libc.so.6", O_RDONLY|O_CLOEXEC) = 3
[00007faf9cafb347] read(3, "\177ELF\2\1\1\3\0\0\0\0\0\0\0\0\3\0>\0\1\0\0\0P\t\2\0\0\0\0\0"..., 832) = 832
[00007faf9cafb2b4] fstat(3, {st_mode=S_IFREG|0755, st_size=1868984, ...}) = 0
[00007faf9cafb47a] mmap(NULL, 3971488, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x7faf9c716000
[00007faf9cafb517] mprotect(0x7faf9c8d6000, 2097152, PROT_NONE) = 0
...
$ sudo strace -i df -h
[00007f0d7534c777] execve("/bin/df", ["df", "-h"], [/* 17 vars */]) = 0
[00007faf9cafa4b9] brk(NULL)            = 0x12f0000
[00007faf9cafb387] access("/etc/ld.so.nohwcap", F_OK) = -1 ENOENT (No such file or directory)
[00007faf9cafb47a] mmap(NULL, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7faf9cd03000
[00007faf9cafb387] access("/etc/ld.so.preload", R_OK) = -1 ENOENT (No such file or directory)
[00007faf9cafb327] open("/etc/ld.so.cache", O_RDONLY|O_CLOEXEC) = 3
[00007faf9cafb2b4] fstat(3, {st_mode=S_IFREG|0644, st_size=147662, ...}) = 0
[00007faf9cafb47a] mmap(NULL, 147662, PROT_READ, MAP_PRIVATE, 3, 0) = 0x7faf9ccde000
[00007faf9cafb427] close(3)             = 0
[00007faf9cafb387] access("/etc/ld.so.nohwcap", F_OK) = -1 ENOENT (No such file or directory)
[00007faf9cafb327] open("/lib/x86_64-linux-gnu/libc.so.6", O_RDONLY|O_CLOEXEC) = 3
[00007faf9cafb347] read(3, "\177ELF\2\1\1\3\0\0\0\0\0\0\0\0\3\0>\0\1\0\0\0P\t\2\0\0\0\0\0"..., 832) = 832
[00007faf9cafb2b4] fstat(3, {st_mode=S_IFREG|0755, st_size=1868984, ...}) = 0
[00007faf9cafb47a] mmap(NULL, 3971488, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x7faf9c716000
[00007faf9cafb517] mprotect(0x7faf9c8d6000, 2097152, PROT_NONE) = 0
...
$ sudo strace -i df -h
[00007f0d7534c777] execve("/bin/df", ["df", "-h"], [/* 17 vars */]) = 0
[00007faf9cafa4b9] brk(NULL)            = 0x12f0000
[00007faf9cafb387] access("/etc/ld.so.nohwcap", F_OK) = -1 ENOENT (No such file or directory)
[00007faf9cafb47a] mmap(NULL, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7faf9cd03000
[00007faf9cafb387] access("/etc/ld.so.preload", R_OK) = -1 ENOENT (No such file or directory)
[00007faf9cafb327] open("/etc/ld.so.cache", O_RDONLY|O_CLOEXEC) = 3
[00007faf9cafb2b4] fstat(3, {st_mode=S_IFREG|0644, st_size=147662, ...}) = 0
[00007faf9cafb47a] mmap(NULL, 147662, PROT_READ, MAP_PRIVATE, 3, 0) = 0x7faf9ccde000
[00007faf9cafb427] close(3)             = 0
[00007faf9cafb387] access("/etc/ld.so.nohwcap", F_OK) = -1 ENOENT (No such file or directory)
[00007faf9cafb327] open("/lib/x86_64-linux-gnu/libc.so.6", O_RDONLY|O_CLOEXEC) = 3
[00007faf9cafb347] read(3, "\177ELF\2\1\1\3\0\0\0\0\0\0\0\0\3\0>\0\1\0\0\0P\t\2\0\0\0\0\0"..., 832) = 832
[00007faf9cafb2b4] fstat(3, {st_mode=S_IFREG|0755, st_size=1868984, ...}) = 0
[00007faf9cafb47a] mmap(NULL, 3971488, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x7faf9c716000
[00007faf9cafb517] mprotect(0x7faf9c8d6000, 2097152, PROT_NONE) = 0
...
$ sudo strace -i df -h
[00007f0d7534c777] execve("/bin/df", ["df", "-h"], [/* 17 vars */]) = 0
[00007faf9cafa4b9] brk(NULL)            = 0x12f0000
[00007faf9cafb387] access("/etc/ld.so.nohwcap", F_OK) = -1 ENOENT (No such file or directory)
[00007faf9cafb47a] mmap(NULL, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7faf9cd03000
[00007faf9cafb387] access("/etc/ld.so.preload", R_OK) = -1 ENOENT (No such file or directory)
[00007faf9cafb327] open("/etc/ld.so.cache", O_RDONLY|O_CLOEXEC) = 3
[00007faf9cafb2b4] fstat(3, {st_mode=S_IFREG|0644, st_size=147662, ...}) = 0
[00007faf9cafb47a] mmap(NULL, 147662, PROT_READ, MAP_PRIVATE, 3, 0) = 0x7faf9ccde000
[00007faf9cafb427] close(3)             = 0
[00007faf9cafb387] access("/etc/ld.so.nohwcap", F_OK) = -1 ENOENT (No such file or directory)
[00007faf9cafb327] open("/lib/x86_64-linux-gnu/libc.so.6", O_RDONLY|O_CLOEXEC) = 3
[00007faf9cafb347] read(3, "\177ELF\2\1\1\3\0\0\0\0\0\0\0\0\3\0>\0\1\0\0\0P\t\2\0\0\0\0\0"..., 832) = 832
[00007faf9cafb2b4] fstat(3, {st_mode=S_IFREG|0755, st_size=1868984, ...}) = 0
[00007faf9cafb47a] mmap(NULL, 3971488, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x7faf9c716000
[00007faf9cafb517] mprotect(0x7faf9c8d6000, 2097152, PROT_NONE) = 0
...
$ sudo strace -i df -h
[00007f0d7534c777] execve("/bin/df", ["df", "-h"], [/* 17 vars */]) = 0
[00007faf9cafa4b9] brk(NULL)            = 0x12f0000
[00007faf9cafb387] access("/etc/ld.so.nohwcap", F_OK) = -1 ENOENT (No such file or directory)
[00007faf9cafb47a] mmap(NULL, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7faf9cd03000
[00007faf9cafb387] access("/etc/ld.so.preload", R_OK) = -1 ENOENT (No such file or directory)
[00007faf9cafb327] open("/etc/ld.so.cache", O_RDONLY|O_CLOEXEC) = 3
[00007faf9cafb2b4] fstat(3, {st_mode=S_IFREG|0644, st_size=147662, ...}) = 0
[00007faf9cafb47a] mmap(NULL, 147662, PROT_READ, MAP_PRIVATE, 3, 0) = 0x7faf9ccde000
[00007faf9cafb427] close(3)             = 0
[00007faf9cafb387] access("/etc/ld.so.nohwcap", F_OK) = -1 ENOENT (No such file or directory)
[00007faf9cafb327] open("/lib/x86_64-linux-gnu/libc.so.6", O_RDONLY|O_CLOEXEC) = 3
[00007faf9cafb347] read(3, "\177ELF\2\1\1\3\0\0\0\0\0\0\0\0\3\0>\0\1\0\0\0P\t\2\0\0\0\0\0"..., 832) = 832
[00007faf9cafb2b4] fstat(3, {st_mode=S_IFREG|0755, st_size=1868984, ...}) = 0
[00007faf9cafb47a] mmap(NULL, 3971488, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x7faf9c716000
[00007faf9cafb517] mprotect(0x7faf9c8d6000, 2097152, PROT_NONE) = 0
...
$ sudo strace -i df -h
[00007f0d7534c777] execve("/bin/df", ["df", "-h"], [/* 17 vars */]) = 0
[00007faf9cafa4b9] brk(NULL)            = 0x12f0000
[00007faf9cafb387] access("/etc/ld.so.nohwcap", F_OK) = -1 ENOENT (No such file or directory)
[00007faf9cafb47a] mmap(NULL, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7faf9cd03000
[00007faf9cafb387] access("/etc/ld.so.preload", R_OK) = -1 ENOENT (No such file or directory)
[00007faf9cafb327] open("/etc/ld.so.cache", O_RDONLY|O_CLOEXEC) = 3
[00007faf9cafb2b4] fstat(3, {st_mode=S_IFREG|0644, st_size=147662, ...}) = 0
[00007faf9cafb47a] mmap(NULL, 147662, PROT_READ, MAP_PRIVATE, 3, 0) = 0x7faf9ccde000
[00007faf9cafb427] close(3)             = 0
[00007faf9cafb387] access("/etc/ld.so.nohwcap", F_OK) = -1 ENOENT (No such file or directory)
[00007faf9cafb327] open("/lib/x86_64-linux-gnu/libc.so.6", O_RDONLY|O_CLOEXEC) = 3
[00007faf9cafb347] read(3, "\177ELF\2\1\1\3\0\0\0\0\0\0\0\0\3\0>\0\1\0\0\0P\t\2\0\0\0\0\0"..., 832) = 832
[00007faf9cafb2b4] fstat(3, {st_mode=S_IFREG|0755, st_size=1868984, ...}) = 0
[00007faf9cafb47a] mmap(NULL, 3971488, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x7faf9c716000
[00007faf9cafb517] mprotect(0x7faf9c8d6000, 2097152, PROT_NONE) = 0
...
$ sudo strace -i df -h
[00007f0d7534c777] execve("/bin/df", ["df", "-h"], [/* 17 vars */]) = 0
[00007faf9cafa4b9] brk(NULL)            = 0x12f0000
[00007faf9cafb387] access("/etc/ld.so.nohwcap", F_OK) = -1 ENOENT (No such file or directory)
[00007faf9cafb47a] mmap(NULL, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7faf9cd03000
[00007faf9cafb387] access("/etc/ld.so.preload", R_OK) = -1 ENOENT (No such file or directory)
[00007faf9cafb327] open("/etc/ld.so.cache", O_RDONLY|O_CLOEXEC) = 3
[00007faf9cafb2b4] fstat(3, {st_mode=S_IFREG|0644, st_size=147662, ...}) = 0
[00007faf9cafb47a] mmap(NULL, 147662, PROT_READ, MAP_PRIVATE, 3, 0) = 0x7faf9ccde000
[00007faf9cafb427] close(3)             = 0
[00007faf9cafb387] access("/etc/ld.so.nohwcap", F_OK) = -1 ENOENT (No such file or directory)
[00007faf9cafb327] open("/lib/x86_64-linux-gnu/libc.so.6", O_RDONLY|O_CLOEXEC) = 3
[00007faf9cafb347] read(3, "\177ELF\2\1\1\3\0\0\0\0\0\0\0\0\3\0>\0\1\0\0\0P\t\2\0\0\0\0\0"..., 832) = 832
[00007faf9cafb2b4] fstat(3, {st_mode=S_IFREG|0755, st_size=1868984, ...}) = 0
[00007faf9cafb47a] mmap(NULL, 3971488, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x7faf9c716000
[00007faf9cafb517] mprotect(0x7faf9c8d6000, 2097152, PROT_NONE) = 0
...
$ sudo strace -i df -h
[00007f0d7534c777] execve("/bin/df", ["df", "-h"], [/* 17 vars */]) = 0
[00007faf9cafa4b9] brk(NULL)            = 0x12f0000
[00007faf9cafb387] access("/etc/ld.so.nohwcap", F_OK) = -1 ENOENT (No such file or directory)
[00007faf9cafb47a] mmap(NULL, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7faf9cd03000
[00007faf9cafb387] access("/etc/ld.so.preload", R_OK) = -1 ENOENT (No such file or directory)
[00007faf9cafb327] open("/etc/ld.so.cache", O_RDONLY|O_CLOEXEC) = 3
[00007faf9cafb2b4] fstat(3, {st_mode=S_IFREG|0644, st_size=147662, ...}) = 0
[00007faf9cafb47a] mmap(NULL, 147662, PROT_READ, MAP_PRIVATE, 3, 0) = 0x7faf9ccde000
[00007faf9cafb427] close(3)             = 0
[00007faf9cafb387] access("/etc/ld.so.nohwcap", F_OK) = -1 ENOENT (No such file or directory)
[00007faf9cafb327] open("/lib/x86_64-linux-gnu/libc.so.6", O_RDONLY|O_CLOEXEC) = 3
[00007faf9cafb347] read(3, "\177ELF\2\1\1\3\0\0\0\0\0\0\0\0\3\0>\0\1\0\0\0P\t\2\0\0\0\0\0"..., 832) = 832
[00007faf9cafb2b4] fstat(3, {st_mode=S_IFREG|0755, st_size=1868984, ...}) = 0
[00007faf9cafb47a] mmap(NULL, 3971488, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x7faf9c716000
[00007faf9cafb517] mprotect(0x7faf9c8d6000, 2097152, PROT_NONE) = 0
...
$ sudo strace -i df -h
[00007f0d7534c777] execve("/bin/df", ["df", "-h"], [/* 17 vars */]) = 0
[00007faf9cafa4b9] brk(NULL)            = 0x12f0000
[00007faf9cafb387] access("/etc/ld.so.nohwcap", F_OK) = -1 ENOENT (No such file or directory)
[00007faf9cafb47a] mmap(NULL, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7faf9cd03000
[00007faf9cafb387] access("/etc/ld.so.preload", R_OK) = -1 ENOENT (No such file or directory)
[00007faf9cafb327] open("/etc/ld.so.cache", O_RDONLY|O_CLOEXEC) = 3
[00007faf9cafb2b4] fstat(3, {st_mode=S_IFREG|0644, st_size=147662, ...}) = 0
[00007faf9cafb47a] mmap(NULL, 147662, PROT_READ, MAP_PRIVATE, 3, 0) = 0x7faf9ccde000
[00007faf9cafb427] close(3)             = 0
[00007faf9cafb387] access("/etc/ld.so.nohwcap", F_OK) = -1 ENOENT (No such file or directory)
[00007faf9cafb327] open("/lib/x86_64-linux-gnu/libc.so.6", O_RDONLY|O_CLOEXEC) = 3
[00007faf9cafb347] read(3, "\177ELF\2\1\1\3\0\0\0\0\0\0\0\0\3\0>\0\1\0\0\0P\t\2\0\0\0\0\0"..., 832) = 832
[00007faf9cafb2b4] fstat(3, {st_mode=S_IFREG|0755, st_size=1868984, ...}) = 0
[00007faf9cafb47a] mmap(NULL, 3971488, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x7faf9c716000
[00007faf9cafb517] mprotect(0x7faf9c8d6000, 2097152, PROT_NONE) = 0
...
$ sudo strace -i df -h
[00007f0d7534c777] execve("/bin/df", ["df", "-h"], [/* 17 vars */]) = 0
[00007faf9cafa4b9] brk(NULL)            = 0x12f0000
[00007faf9cafb387] access("/etc/ld.so.nohwcap", F_OK) = -1 ENOENT (No such file or directory)
[00007faf9cafb47a] mmap(NULL, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7faf9cd03000
[00007faf9cafb387] access("/etc/ld.so.preload", R_OK) = -1 ENOENT (No such file or directory)
[00007faf9cafb327] open("/etc/ld.so.cache", O_RDONLY|O_CLOEXEC) = 3
[00007faf9cafb2b4] fstat(3, {st_mode=S_IFREG|0644, st_size=147662, ...}) = 0
[00007faf9cafb47a] mmap(NULL, 147662, PROT_READ, MAP_PRIVATE, 3, 0) = 0x7faf9ccde000
[00007faf9cafb427] close(3)             = 0
[00007faf9cafb387] access("/etc/ld.so.nohwcap", F_OK) = -1 ENOENT (No such file or directory)
[00007faf9cafb327] open("/lib/x86_64-linux-gnu/libc.so.6", O_RDONLY|O_CLOEXEC) = 3
[00007faf9cafb347] read(3, "\177ELF\2\1\1\3\0\0\0\0\0\0\0\0\3\0>\0\1\0\0\0P\t\2\0\0\0\0\0"..., 832) = 832
[00007faf9cafb2b4] fstat(3, {st_mode=S_IFREG|0755, st_size=1868984, ...}) = 0
[00007faf9cafb47a] mmap(NULL, 3971488, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x7faf9c716000
[00007faf9cafb517] mprotect(0x7faf9c8d6000, 2097152, PROT_NONE) = 0
...
$ sudo strace -i df -h
[00007f0d7534c777] execve("/bin/df", ["df", "-h"], [/* 17 vars */]) = 0
[00007faf9cafa4b9] brk(NULL)            = 0x12f0000
[00007faf9cafb387] access("/etc/ld.so.nohwcap", F_OK) = -1 ENOENT (No such file or directory)
[00007faf9cafb47a] mmap(NULL, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7faf9cd03000
[00007faf9cafb387] access("/etc/ld.so.preload", R_OK) = -1 ENOENT (No such file or directory)
[00007faf9cafb327] open("/etc/ld.so.cache", O_RDONLY|O_CLOEXEC) = 3
[00007faf9cafb2b4] fstat(3, {st_mode=S_IFREG|0644, st_size=147662, ...}) = 0
[00007faf9cafb47a] mmap(NULL, 147662, PROT_READ, MAP_PRIVATE, 3, 0) = 0x7faf9ccde000
[00007faf9cafb427] close(3)             = 0
[00007faf9cafb387] access("/etc/ld.so.nohwcap", F_OK) = -1 ENOENT (No such file or directory)
[00007faf9cafb327] open("/lib/x86_64-linux-gnu/libc.so.6", O_RDONLY|O_CLOEXEC) = 3
[00007faf9cafb347] read(3, "\177ELF\2\1\1\3\0\0\0\0\0\0\0\0\3\0>\0\1\0\0\0P\t\2\0\0\0\0\0"..., 832) = 832
[00007faf9cafb2b4] fstat(3, {st_mode=S_IFREG|0755, st_size=1868984, ...}) = 0
[00007faf9cafb47a] mmap(NULL, 3971488, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x7faf9c716000
[00007faf9cafb517] mprotect(0x7faf9c8d6000, 2097152, PROT_NONE) = 0
...
$ sudo strace -i df -h
[00007f0d7534c777] execve("/bin/df", ["df", "-h"], [/* 17 vars */]) = 0
[00007faf9cafa4b9] brk(NULL)            = 0x12f0000
[00007faf9cafb387] access("/etc/ld.so.nohwcap", F_OK) = -1 ENOENT (No such file or directory)
[00007faf9cafb47a] mmap(NULL, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7faf9cd03000
[00007faf9cafb387] access("/etc/ld.so.preload", R_OK) = -1 ENOENT (No such file or directory)
[00007faf9cafb327] open("/etc/ld.so.cache", O_RDONLY|O_CLOEXEC) = 3
[00007faf9cafb2b4] fstat(3, {st_mode=S_IFREG|0644, st_size=147662, ...}) = 0
[00007faf9cafb47a] mmap(NULL, 147662, PROT_READ, MAP_PRIVATE, 3, 0) = 0x7faf9ccde000
[00007faf9cafb427] close(3)             = 0
[00007faf9cafb387] access("/etc/ld.so.nohwcap", F_OK) = -1 ENOENT (No such file or directory)
[00007faf9cafb327] open("/lib/x86_64-linux-gnu/libc.so.6", O_RDONLY|O_CLOEXEC) = 3
[00007faf9cafb347] read(3, "\177ELF\2\1\1\3\0\0\0\0\0\0\0\0\3\0>\0\1\0\0\0P\t\2\0\0\0\0\0"..., 832) = 832
[00007faf9cafb2b4] fstat(3, {st_mode=S_IFREG|0755, st_size=1868984, ...}) = 0
[00007faf9cafb47a] mmap(NULL, 3971488, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x7faf9c716000
[00007faf9cafb517] mprotect(0x7faf9c8d6000, 2097152, PROT_NONE) = 0
...
$ sudo strace -i df -h
[00007f0d7534c777] execve("/bin/df", ["df", "-h"], [/* 17 vars */]) = 0
[00007faf9cafa4b9] brk(NULL)            = 0x12f0000
[00007faf9cafb387] access("/etc/ld.so.nohwcap", F_OK) = -1 ENOENT (No such file or directory)
[00007faf9cafb47a] mmap(NULL, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7faf9cd03000
[00007faf9cafb387] access("/etc/ld.so.preload", R_OK) = -1 ENOENT (No such file or directory)
[00007faf9cafb327] open("/etc/ld.so.cache", O_RDONLY|O_CLOEXEC) = 3
[00007faf9cafb2b4] fstat(3, {st_mode=S_IFREG|0644, st_size=147662, ...}) = 0
[00007faf9cafb47a] mmap(NULL, 147662, PROT_READ, MAP_PRIVATE, 3, 0) = 0x7faf9ccde000
[00007faf9cafb427] close(3)             = 0
[00007faf9cafb387] access("/etc/ld.so.nohwcap", F_OK) = -1 ENOENT (No such file or directory)
[00007faf9cafb327] open("/lib/x86_64-linux-gnu/libc.so.6", O_RDONLY|O_CLOEXEC) = 3
[00007faf9cafb347] read(3, "\177ELF\2\1\1\3\0\0\0\0\0\0\0\0\3\0>\0\1\0\0\0P\t\2\0\0\0\0\0"..., 832) = 832
[00007faf9cafb2b4] fstat(3, {st_mode=S_IFREG|0755, st_size=1868984, ...}) = 0
[00007faf9cafb47a] mmap(NULL, 3971488, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x7faf9c716000
[00007faf9cafb517] mprotect(0x7faf9c8d6000, 2097152, PROT_NONE) = 0
...

5. Mostrar la hora del día para cada línea de salida de seguimiento

También puede imprimir la hora del día para cada línea en la salida de seguimiento, pasando el indicador -t .

$ sudo strace -t df -h

15:19:25 execve("/bin/df", ["df", "-h"], [/* 17 vars */]) = 0
15:19:25 brk(NULL)                      = 0x234c000
15:19:25 access("/etc/ld.so.nohwcap", F_OK) = -1 ENOENT (No such file or directory)
15:19:25 mmap(NULL, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f8c7f1d9000
15:19:25 access("/etc/ld.so.preload", R_OK) = -1 ENOENT (No such file or directory)
15:19:25 open("/etc/ld.so.cache", O_RDONLY|O_CLOEXEC) = 3
15:19:25 fstat(3, {st_mode=S_IFREG|0644, st_size=147662, ...}) = 0
15:19:25 mmap(NULL, 147662, PROT_READ, MAP_PRIVATE, 3, 0) = 0x7f8c7f1b4000
15:19:25 close(3)                       = 0
15:19:25 access("/etc/ld.so.nohwcap", F_OK) = -1 ENOENT (No such file or directory)
15:19:25 open("/lib/x86_64-linux-gnu/libc.so.6", O_RDONLY|O_CLOEXEC) = 3
15:19:25 read(3, "7ELF
$ sudo strace -t df -h
15:19:25 execve("/bin/df", ["df", "-h"], [/* 17 vars */]) = 0
15:19:25 brk(NULL)                      = 0x234c000
15:19:25 access("/etc/ld.so.nohwcap", F_OK) = -1 ENOENT (No such file or directory)
15:19:25 mmap(NULL, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f8c7f1d9000
15:19:25 access("/etc/ld.so.preload", R_OK) = -1 ENOENT (No such file or directory)
15:19:25 open("/etc/ld.so.cache", O_RDONLY|O_CLOEXEC) = 3
15:19:25 fstat(3, {st_mode=S_IFREG|0644, st_size=147662, ...}) = 0
15:19:25 mmap(NULL, 147662, PROT_READ, MAP_PRIVATE, 3, 0) = 0x7f8c7f1b4000
15:19:25 close(3)                       = 0
15:19:25 access("/etc/ld.so.nohwcap", F_OK) = -1 ENOENT (No such file or directory)
15:19:25 open("/lib/x86_64-linux-gnu/libc.so.6", O_RDONLY|O_CLOEXEC) = 3
15:19:25 read(3, "\177ELF\2\1\1\3\0\0\0\0\0\0\0\0\3\0>\0\1\0\0\0P\t\2\0\0\0\0\0"..., 832) = 832
15:19:25 fstat(3, {st_mode=S_IFREG|0755, st_size=1868984, ...}) = 0
15:19:25 mmap(NULL, 3971488, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x7f8c7ebec000
15:19:25 mprotect(0x7f8c7edac000, 2097152, PROT_NONE) = 0
...
$ sudo strace -t df -h
15:19:25 execve("/bin/df", ["df", "-h"], [/* 17 vars */]) = 0
15:19:25 brk(NULL)                      = 0x234c000
15:19:25 access("/etc/ld.so.nohwcap", F_OK) = -1 ENOENT (No such file or directory)
15:19:25 mmap(NULL, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f8c7f1d9000
15:19:25 access("/etc/ld.so.preload", R_OK) = -1 ENOENT (No such file or directory)
15:19:25 open("/etc/ld.so.cache", O_RDONLY|O_CLOEXEC) = 3
15:19:25 fstat(3, {st_mode=S_IFREG|0644, st_size=147662, ...}) = 0
15:19:25 mmap(NULL, 147662, PROT_READ, MAP_PRIVATE, 3, 0) = 0x7f8c7f1b4000
15:19:25 close(3)                       = 0
15:19:25 access("/etc/ld.so.nohwcap", F_OK) = -1 ENOENT (No such file or directory)
15:19:25 open("/lib/x86_64-linux-gnu/libc.so.6", O_RDONLY|O_CLOEXEC) = 3
15:19:25 read(3, "\177ELF\2\1\1\3\0\0\0\0\0\0\0\0\3\0>\0\1\0\0\0P\t\2\0\0\0\0\0"..., 832) = 832
15:19:25 fstat(3, {st_mode=S_IFREG|0755, st_size=1868984, ...}) = 0
15:19:25 mmap(NULL, 3971488, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x7f8c7ebec000
15:19:25 mprotect(0x7f8c7edac000, 2097152, PROT_NONE) = 0
...
$ sudo strace -t df -h
15:19:25 execve("/bin/df", ["df", "-h"], [/* 17 vars */]) = 0
15:19:25 brk(NULL)                      = 0x234c000
15:19:25 access("/etc/ld.so.nohwcap", F_OK) = -1 ENOENT (No such file or directory)
15:19:25 mmap(NULL, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f8c7f1d9000
15:19:25 access("/etc/ld.so.preload", R_OK) = -1 ENOENT (No such file or directory)
15:19:25 open("/etc/ld.so.cache", O_RDONLY|O_CLOEXEC) = 3
15:19:25 fstat(3, {st_mode=S_IFREG|0644, st_size=147662, ...}) = 0
15:19:25 mmap(NULL, 147662, PROT_READ, MAP_PRIVATE, 3, 0) = 0x7f8c7f1b4000
15:19:25 close(3)                       = 0
15:19:25 access("/etc/ld.so.nohwcap", F_OK) = -1 ENOENT (No such file or directory)
15:19:25 open("/lib/x86_64-linux-gnu/libc.so.6", O_RDONLY|O_CLOEXEC) = 3
15:19:25 read(3, "\177ELF\2\1\1\3\0\0\0\0\0\0\0\0\3\0>\0\1\0\0\0P\t\2\0\0\0\0\0"..., 832) = 832
15:19:25 fstat(3, {st_mode=S_IFREG|0755, st_size=1868984, ...}) = 0
15:19:25 mmap(NULL, 3971488, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x7f8c7ebec000
15:19:25 mprotect(0x7f8c7edac000, 2097152, PROT_NONE) = 0
...
$ sudo strace -t df -h
15:19:25 execve("/bin/df", ["df", "-h"], [/* 17 vars */]) = 0
15:19:25 brk(NULL)                      = 0x234c000
15:19:25 access("/etc/ld.so.nohwcap", F_OK) = -1 ENOENT (No such file or directory)
15:19:25 mmap(NULL, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f8c7f1d9000
15:19:25 access("/etc/ld.so.preload", R_OK) = -1 ENOENT (No such file or directory)
15:19:25 open("/etc/ld.so.cache", O_RDONLY|O_CLOEXEC) = 3
15:19:25 fstat(3, {st_mode=S_IFREG|0644, st_size=147662, ...}) = 0
15:19:25 mmap(NULL, 147662, PROT_READ, MAP_PRIVATE, 3, 0) = 0x7f8c7f1b4000
15:19:25 close(3)                       = 0
15:19:25 access("/etc/ld.so.nohwcap", F_OK) = -1 ENOENT (No such file or directory)
15:19:25 open("/lib/x86_64-linux-gnu/libc.so.6", O_RDONLY|O_CLOEXEC) = 3
15:19:25 read(3, "\177ELF\2\1\1\3\0\0\0\0\0\0\0\0\3\0>\0\1\0\0\0P\t\2\0\0\0\0\0"..., 832) = 832
15:19:25 fstat(3, {st_mode=S_IFREG|0755, st_size=1868984, ...}) = 0
15:19:25 mmap(NULL, 3971488, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x7f8c7ebec000
15:19:25 mprotect(0x7f8c7edac000, 2097152, PROT_NONE) = 0
...
$ sudo strace -t df -h
15:19:25 execve("/bin/df", ["df", "-h"], [/* 17 vars */]) = 0
15:19:25 brk(NULL)                      = 0x234c000
15:19:25 access("/etc/ld.so.nohwcap", F_OK) = -1 ENOENT (No such file or directory)
15:19:25 mmap(NULL, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f8c7f1d9000
15:19:25 access("/etc/ld.so.preload", R_OK) = -1 ENOENT (No such file or directory)
15:19:25 open("/etc/ld.so.cache", O_RDONLY|O_CLOEXEC) = 3
15:19:25 fstat(3, {st_mode=S_IFREG|0644, st_size=147662, ...}) = 0
15:19:25 mmap(NULL, 147662, PROT_READ, MAP_PRIVATE, 3, 0) = 0x7f8c7f1b4000
15:19:25 close(3)                       = 0
15:19:25 access("/etc/ld.so.nohwcap", F_OK) = -1 ENOENT (No such file or directory)
15:19:25 open("/lib/x86_64-linux-gnu/libc.so.6", O_RDONLY|O_CLOEXEC) = 3
15:19:25 read(3, "\177ELF\2\1\1\3\0\0\0\0\0\0\0\0\3\0>\0\1\0\0\0P\t\2\0\0\0\0\0"..., 832) = 832
15:19:25 fstat(3, {st_mode=S_IFREG|0755, st_size=1868984, ...}) = 0
15:19:25 mmap(NULL, 3971488, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x7f8c7ebec000
15:19:25 mprotect(0x7f8c7edac000, 2097152, PROT_NONE) = 0
...
$ sudo strace -t df -h
15:19:25 execve("/bin/df", ["df", "-h"], [/* 17 vars */]) = 0
15:19:25 brk(NULL)                      = 0x234c000
15:19:25 access("/etc/ld.so.nohwcap", F_OK) = -1 ENOENT (No such file or directory)
15:19:25 mmap(NULL, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f8c7f1d9000
15:19:25 access("/etc/ld.so.preload", R_OK) = -1 ENOENT (No such file or directory)
15:19:25 open("/etc/ld.so.cache", O_RDONLY|O_CLOEXEC) = 3
15:19:25 fstat(3, {st_mode=S_IFREG|0644, st_size=147662, ...}) = 0
15:19:25 mmap(NULL, 147662, PROT_READ, MAP_PRIVATE, 3, 0) = 0x7f8c7f1b4000
15:19:25 close(3)                       = 0
15:19:25 access("/etc/ld.so.nohwcap", F_OK) = -1 ENOENT (No such file or directory)
15:19:25 open("/lib/x86_64-linux-gnu/libc.so.6", O_RDONLY|O_CLOEXEC) = 3
15:19:25 read(3, "\177ELF\2\1\1\3\0\0\0\0\0\0\0\0\3\0>\0\1\0\0\0P\t\2\0\0\0\0\0"..., 832) = 832
15:19:25 fstat(3, {st_mode=S_IFREG|0755, st_size=1868984, ...}) = 0
15:19:25 mmap(NULL, 3971488, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x7f8c7ebec000
15:19:25 mprotect(0x7f8c7edac000, 2097152, PROT_NONE) = 0
...
$ sudo strace -t df -h
15:19:25 execve("/bin/df", ["df", "-h"], [/* 17 vars */]) = 0
15:19:25 brk(NULL)                      = 0x234c000
15:19:25 access("/etc/ld.so.nohwcap", F_OK) = -1 ENOENT (No such file or directory)
15:19:25 mmap(NULL, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f8c7f1d9000
15:19:25 access("/etc/ld.so.preload", R_OK) = -1 ENOENT (No such file or directory)
15:19:25 open("/etc/ld.so.cache", O_RDONLY|O_CLOEXEC) = 3
15:19:25 fstat(3, {st_mode=S_IFREG|0644, st_size=147662, ...}) = 0
15:19:25 mmap(NULL, 147662, PROT_READ, MAP_PRIVATE, 3, 0) = 0x7f8c7f1b4000
15:19:25 close(3)                       = 0
15:19:25 access("/etc/ld.so.nohwcap", F_OK) = -1 ENOENT (No such file or directory)
15:19:25 open("/lib/x86_64-linux-gnu/libc.so.6", O_RDONLY|O_CLOEXEC) = 3
15:19:25 read(3, "\177ELF\2\1\1\3\0\0\0\0\0\0\0\0\3\0>\0\1\0\0\0P\t\2\0\0\0\0\0"..., 832) = 832
15:19:25 fstat(3, {st_mode=S_IFREG|0755, st_size=1868984, ...}) = 0
15:19:25 mmap(NULL, 3971488, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x7f8c7ebec000
15:19:25 mprotect(0x7f8c7edac000, 2097152, PROT_NONE) = 0
...
$ sudo strace -t df -h
15:19:25 execve("/bin/df", ["df", "-h"], [/* 17 vars */]) = 0
15:19:25 brk(NULL)                      = 0x234c000
15:19:25 access("/etc/ld.so.nohwcap", F_OK) = -1 ENOENT (No such file or directory)
15:19:25 mmap(NULL, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f8c7f1d9000
15:19:25 access("/etc/ld.so.preload", R_OK) = -1 ENOENT (No such file or directory)
15:19:25 open("/etc/ld.so.cache", O_RDONLY|O_CLOEXEC) = 3
15:19:25 fstat(3, {st_mode=S_IFREG|0644, st_size=147662, ...}) = 0
15:19:25 mmap(NULL, 147662, PROT_READ, MAP_PRIVATE, 3, 0) = 0x7f8c7f1b4000
15:19:25 close(3)                       = 0
15:19:25 access("/etc/ld.so.nohwcap", F_OK) = -1 ENOENT (No such file or directory)
15:19:25 open("/lib/x86_64-linux-gnu/libc.so.6", O_RDONLY|O_CLOEXEC) = 3
15:19:25 read(3, "\177ELF\2\1\1\3\0\0\0\0\0\0\0\0\3\0>\0\1\0\0\0P\t\2\0\0\0\0\0"..., 832) = 832
15:19:25 fstat(3, {st_mode=S_IFREG|0755, st_size=1868984, ...}) = 0
15:19:25 mmap(NULL, 3971488, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x7f8c7ebec000
15:19:25 mprotect(0x7f8c7edac000, 2097152, PROT_NONE) = 0
...
$ sudo strace -t df -h
15:19:25 execve("/bin/df", ["df", "-h"], [/* 17 vars */]) = 0
15:19:25 brk(NULL)                      = 0x234c000
15:19:25 access("/etc/ld.so.nohwcap", F_OK) = -1 ENOENT (No such file or directory)
15:19:25 mmap(NULL, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f8c7f1d9000
15:19:25 access("/etc/ld.so.preload", R_OK) = -1 ENOENT (No such file or directory)
15:19:25 open("/etc/ld.so.cache", O_RDONLY|O_CLOEXEC) = 3
15:19:25 fstat(3, {st_mode=S_IFREG|0644, st_size=147662, ...}) = 0
15:19:25 mmap(NULL, 147662, PROT_READ, MAP_PRIVATE, 3, 0) = 0x7f8c7f1b4000
15:19:25 close(3)                       = 0
15:19:25 access("/etc/ld.so.nohwcap", F_OK) = -1 ENOENT (No such file or directory)
15:19:25 open("/lib/x86_64-linux-gnu/libc.so.6", O_RDONLY|O_CLOEXEC) = 3
15:19:25 read(3, "\177ELF\2\1\1\3\0\0\0\0\0\0\0\0\3\0>\0\1\0\0\0P\t\2\0\0\0\0\0"..., 832) = 832
15:19:25 fstat(3, {st_mode=S_IFREG|0755, st_size=1868984, ...}) = 0
15:19:25 mmap(NULL, 3971488, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x7f8c7ebec000
15:19:25 mprotect(0x7f8c7edac000, 2097152, PROT_NONE) = 0
...
$ sudo strace -t df -h
15:19:25 execve("/bin/df", ["df", "-h"], [/* 17 vars */]) = 0
15:19:25 brk(NULL)                      = 0x234c000
15:19:25 access("/etc/ld.so.nohwcap", F_OK) = -1 ENOENT (No such file or directory)
15:19:25 mmap(NULL, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f8c7f1d9000
15:19:25 access("/etc/ld.so.preload", R_OK) = -1 ENOENT (No such file or directory)
15:19:25 open("/etc/ld.so.cache", O_RDONLY|O_CLOEXEC) = 3
15:19:25 fstat(3, {st_mode=S_IFREG|0644, st_size=147662, ...}) = 0
15:19:25 mmap(NULL, 147662, PROT_READ, MAP_PRIVATE, 3, 0) = 0x7f8c7f1b4000
15:19:25 close(3)                       = 0
15:19:25 access("/etc/ld.so.nohwcap", F_OK) = -1 ENOENT (No such file or directory)
15:19:25 open("/lib/x86_64-linux-gnu/libc.so.6", O_RDONLY|O_CLOEXEC) = 3
15:19:25 read(3, "\177ELF\2\1\1\3\0\0\0\0\0\0\0\0\3\0>\0\1\0\0\0P\t\2\0\0\0\0\0"..., 832) = 832
15:19:25 fstat(3, {st_mode=S_IFREG|0755, st_size=1868984, ...}) = 0
15:19:25 mmap(NULL, 3971488, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x7f8c7ebec000
15:19:25 mprotect(0x7f8c7edac000, 2097152, PROT_NONE) = 0
...
$ sudo strace -t df -h
15:19:25 execve("/bin/df", ["df", "-h"], [/* 17 vars */]) = 0
15:19:25 brk(NULL)                      = 0x234c000
15:19:25 access("/etc/ld.so.nohwcap", F_OK) = -1 ENOENT (No such file or directory)
15:19:25 mmap(NULL, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f8c7f1d9000
15:19:25 access("/etc/ld.so.preload", R_OK) = -1 ENOENT (No such file or directory)
15:19:25 open("/etc/ld.so.cache", O_RDONLY|O_CLOEXEC) = 3
15:19:25 fstat(3, {st_mode=S_IFREG|0644, st_size=147662, ...}) = 0
15:19:25 mmap(NULL, 147662, PROT_READ, MAP_PRIVATE, 3, 0) = 0x7f8c7f1b4000
15:19:25 close(3)                       = 0
15:19:25 access("/etc/ld.so.nohwcap", F_OK) = -1 ENOENT (No such file or directory)
15:19:25 open("/lib/x86_64-linux-gnu/libc.so.6", O_RDONLY|O_CLOEXEC) = 3
15:19:25 read(3, "\177ELF\2\1\1\3\0\0\0\0\0\0\0\0\3\0>\0\1\0\0\0P\t\2\0\0\0\0\0"..., 832) = 832
15:19:25 fstat(3, {st_mode=S_IFREG|0755, st_size=1868984, ...}) = 0
15:19:25 mmap(NULL, 3971488, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x7f8c7ebec000
15:19:25 mprotect(0x7f8c7edac000, 2097152, PROT_NONE) = 0
...
$ sudo strace -t df -h
15:19:25 execve("/bin/df", ["df", "-h"], [/* 17 vars */]) = 0
15:19:25 brk(NULL)                      = 0x234c000
15:19:25 access("/etc/ld.so.nohwcap", F_OK) = -1 ENOENT (No such file or directory)
15:19:25 mmap(NULL, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f8c7f1d9000
15:19:25 access("/etc/ld.so.preload", R_OK) = -1 ENOENT (No such file or directory)
15:19:25 open("/etc/ld.so.cache", O_RDONLY|O_CLOEXEC) = 3
15:19:25 fstat(3, {st_mode=S_IFREG|0644, st_size=147662, ...}) = 0
15:19:25 mmap(NULL, 147662, PROT_READ, MAP_PRIVATE, 3, 0) = 0x7f8c7f1b4000
15:19:25 close(3)                       = 0
15:19:25 access("/etc/ld.so.nohwcap", F_OK) = -1 ENOENT (No such file or directory)
15:19:25 open("/lib/x86_64-linux-gnu/libc.so.6", O_RDONLY|O_CLOEXEC) = 3
15:19:25 read(3, "\177ELF\2\1\1\3\0\0\0\0\0\0\0\0\3\0>\0\1\0\0\0P\t\2\0\0\0\0\0"..., 832) = 832
15:19:25 fstat(3, {st_mode=S_IFREG|0755, st_size=1868984, ...}) = 0
15:19:25 mmap(NULL, 3971488, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x7f8c7ebec000
15:19:25 mprotect(0x7f8c7edac000, 2097152, PROT_NONE) = 0
...
$ sudo strace -t df -h
15:19:25 execve("/bin/df", ["df", "-h"], [/* 17 vars */]) = 0
15:19:25 brk(NULL)                      = 0x234c000
15:19:25 access("/etc/ld.so.nohwcap", F_OK) = -1 ENOENT (No such file or directory)
15:19:25 mmap(NULL, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f8c7f1d9000
15:19:25 access("/etc/ld.so.preload", R_OK) = -1 ENOENT (No such file or directory)
15:19:25 open("/etc/ld.so.cache", O_RDONLY|O_CLOEXEC) = 3
15:19:25 fstat(3, {st_mode=S_IFREG|0644, st_size=147662, ...}) = 0
15:19:25 mmap(NULL, 147662, PROT_READ, MAP_PRIVATE, 3, 0) = 0x7f8c7f1b4000
15:19:25 close(3)                       = 0
15:19:25 access("/etc/ld.so.nohwcap", F_OK) = -1 ENOENT (No such file or directory)
15:19:25 open("/lib/x86_64-linux-gnu/libc.so.6", O_RDONLY|O_CLOEXEC) = 3
15:19:25 read(3, "\177ELF\2\1\1\3\0\0\0\0\0\0\0\0\3\0>\0\1\0\0\0P\t\2\0\0\0\0\0"..., 832) = 832
15:19:25 fstat(3, {st_mode=S_IFREG|0755, st_size=1868984, ...}) = 0
15:19:25 mmap(NULL, 3971488, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x7f8c7ebec000
15:19:25 mprotect(0x7f8c7edac000, 2097152, PROT_NONE) = 0
...
$ sudo strace -t df -h
15:19:25 execve("/bin/df", ["df", "-h"], [/* 17 vars */]) = 0
15:19:25 brk(NULL)                      = 0x234c000
15:19:25 access("/etc/ld.so.nohwcap", F_OK) = -1 ENOENT (No such file or directory)
15:19:25 mmap(NULL, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f8c7f1d9000
15:19:25 access("/etc/ld.so.preload", R_OK) = -1 ENOENT (No such file or directory)
15:19:25 open("/etc/ld.so.cache", O_RDONLY|O_CLOEXEC) = 3
15:19:25 fstat(3, {st_mode=S_IFREG|0644, st_size=147662, ...}) = 0
15:19:25 mmap(NULL, 147662, PROT_READ, MAP_PRIVATE, 3, 0) = 0x7f8c7f1b4000
15:19:25 close(3)                       = 0
15:19:25 access("/etc/ld.so.nohwcap", F_OK) = -1 ENOENT (No such file or directory)
15:19:25 open("/lib/x86_64-linux-gnu/libc.so.6", O_RDONLY|O_CLOEXEC) = 3
15:19:25 read(3, "\177ELF\2\1\1\3\0\0\0\0\0\0\0\0\3\0>\0\1\0\0\0P\t\2\0\0\0\0\0"..., 832) = 832
15:19:25 fstat(3, {st_mode=S_IFREG|0755, st_size=1868984, ...}) = 0
15:19:25 mmap(NULL, 3971488, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x7f8c7ebec000
15:19:25 mprotect(0x7f8c7edac000, 2097152, PROT_NONE) = 0
...
$ sudo strace -t df -h
15:19:25 execve("/bin/df", ["df", "-h"], [/* 17 vars */]) = 0
15:19:25 brk(NULL)                      = 0x234c000
15:19:25 access("/etc/ld.so.nohwcap", F_OK) = -1 ENOENT (No such file or directory)
15:19:25 mmap(NULL, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f8c7f1d9000
15:19:25 access("/etc/ld.so.preload", R_OK) = -1 ENOENT (No such file or directory)
15:19:25 open("/etc/ld.so.cache", O_RDONLY|O_CLOEXEC) = 3
15:19:25 fstat(3, {st_mode=S_IFREG|0644, st_size=147662, ...}) = 0
15:19:25 mmap(NULL, 147662, PROT_READ, MAP_PRIVATE, 3, 0) = 0x7f8c7f1b4000
15:19:25 close(3)                       = 0
15:19:25 access("/etc/ld.so.nohwcap", F_OK) = -1 ENOENT (No such file or directory)
15:19:25 open("/lib/x86_64-linux-gnu/libc.so.6", O_RDONLY|O_CLOEXEC) = 3
15:19:25 read(3, "\177ELF\2\1\1\3\0\0\0\0\0\0\0\0\3\0>\0\1\0\0\0P\t\2\0\0\0\0\0"..., 832) = 832
15:19:25 fstat(3, {st_mode=S_IFREG|0755, st_size=1868984, ...}) = 0
15:19:25 mmap(NULL, 3971488, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x7f8c7ebec000
15:19:25 mprotect(0x7f8c7edac000, 2097152, PROT_NONE) = 0
...
$ sudo strace -t df -h
15:19:25 execve("/bin/df", ["df", "-h"], [/* 17 vars */]) = 0
15:19:25 brk(NULL)                      = 0x234c000
15:19:25 access("/etc/ld.so.nohwcap", F_OK) = -1 ENOENT (No such file or directory)
15:19:25 mmap(NULL, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f8c7f1d9000
15:19:25 access("/etc/ld.so.preload", R_OK) = -1 ENOENT (No such file or directory)
15:19:25 open("/etc/ld.so.cache", O_RDONLY|O_CLOEXEC) = 3
15:19:25 fstat(3, {st_mode=S_IFREG|0644, st_size=147662, ...}) = 0
15:19:25 mmap(NULL, 147662, PROT_READ, MAP_PRIVATE, 3, 0) = 0x7f8c7f1b4000
15:19:25 close(3)                       = 0
15:19:25 access("/etc/ld.so.nohwcap", F_OK) = -1 ENOENT (No such file or directory)
15:19:25 open("/lib/x86_64-linux-gnu/libc.so.6", O_RDONLY|O_CLOEXEC) = 3
15:19:25 read(3, "\177ELF\2\1\1\3\0\0\0\0\0\0\0\0\3\0>\0\1\0\0\0P\t\2\0\0\0\0\0"..., 832) = 832
15:19:25 fstat(3, {st_mode=S_IFREG|0755, st_size=1868984, ...}) = 0
15:19:25 mmap(NULL, 3971488, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x7f8c7ebec000
15:19:25 mprotect(0x7f8c7edac000, 2097152, PROT_NONE) = 0
...
$ sudo strace -t df -h
15:19:25 execve("/bin/df", ["df", "-h"], [/* 17 vars */]) = 0
15:19:25 brk(NULL)                      = 0x234c000
15:19:25 access("/etc/ld.so.nohwcap", F_OK) = -1 ENOENT (No such file or directory)
15:19:25 mmap(NULL, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f8c7f1d9000
15:19:25 access("/etc/ld.so.preload", R_OK) = -1 ENOENT (No such file or directory)
15:19:25 open("/etc/ld.so.cache", O_RDONLY|O_CLOEXEC) = 3
15:19:25 fstat(3, {st_mode=S_IFREG|0644, st_size=147662, ...}) = 0
15:19:25 mmap(NULL, 147662, PROT_READ, MAP_PRIVATE, 3, 0) = 0x7f8c7f1b4000
15:19:25 close(3)                       = 0
15:19:25 access("/etc/ld.so.nohwcap", F_OK) = -1 ENOENT (No such file or directory)
15:19:25 open("/lib/x86_64-linux-gnu/libc.so.6", O_RDONLY|O_CLOEXEC) = 3
15:19:25 read(3, "\177ELF\2\1\1\3\0\0\0\0\0\0\0\0\3\0>\0\1\0\0\0P\t\2\0\0\0\0\0"..., 832) = 832
15:19:25 fstat(3, {st_mode=S_IFREG|0755, st_size=1868984, ...}) = 0
15:19:25 mmap(NULL, 3971488, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x7f8c7ebec000
15:19:25 mprotect(0x7f8c7edac000, 2097152, PROT_NONE) = 0
...
$ sudo strace -t df -h
15:19:25 execve("/bin/df", ["df", "-h"], [/* 17 vars */]) = 0
15:19:25 brk(NULL)                      = 0x234c000
15:19:25 access("/etc/ld.so.nohwcap", F_OK) = -1 ENOENT (No such file or directory)
15:19:25 mmap(NULL, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f8c7f1d9000
15:19:25 access("/etc/ld.so.preload", R_OK) = -1 ENOENT (No such file or directory)
15:19:25 open("/etc/ld.so.cache", O_RDONLY|O_CLOEXEC) = 3
15:19:25 fstat(3, {st_mode=S_IFREG|0644, st_size=147662, ...}) = 0
15:19:25 mmap(NULL, 147662, PROT_READ, MAP_PRIVATE, 3, 0) = 0x7f8c7f1b4000
15:19:25 close(3)                       = 0
15:19:25 access("/etc/ld.so.nohwcap", F_OK) = -1 ENOENT (No such file or directory)
15:19:25 open("/lib/x86_64-linux-gnu/libc.so.6", O_RDONLY|O_CLOEXEC) = 3
15:19:25 read(3, "\177ELF\2\1\1\3\0\0\0\0\0\0\0\0\3\0>\0\1\0\0\0P\t\2\0\0\0\0\0"..., 832) = 832
15:19:25 fstat(3, {st_mode=S_IFREG|0755, st_size=1868984, ...}) = 0
15:19:25 mmap(NULL, 3971488, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x7f8c7ebec000
15:19:25 mprotect(0x7f8c7edac000, 2097152, PROT_NONE) = 0
...

6. Tiempo de comando de impresión invertido en llamadas al sistema

Para mostrar la diferencia de tiempo entre el inicio y el final de cada llamada al sistema realizada por un programa, use la opción -T .

$ sudo strace -T df -h

execve("/bin/df", ["df", "-h"], [/* 17 vars */]) = 0 <0.000287>
brk(NULL)                               = 0xeca000 <0.000035>
access("/etc/ld.so.nohwcap", F_OK)      = -1 ENOENT (No such file or directory) <0.000028>
mmap(NULL, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f9aff2b1000 <0.000020>
access("/etc/ld.so.preload", R_OK)      = -1 ENOENT (No such file or directory) <0.000019>
open("/etc/ld.so.cache", O_RDONLY|O_CLOEXEC) = 3 <0.000022>
fstat(3, {st_mode=S_IFREG|0644, st_size=147662, ...}) = 0 <0.000015>
mmap(NULL, 147662, PROT_READ, MAP_PRIVATE, 3, 0) = 0x7f9aff28c000 <0.000019>
close(3)                                = 0 <0.000014>
...

7. Rastrear solo llamadas específicas del sistema

En el siguiente comando, trace u003d write se conoce como una expresión calificativa, donde trace es un calificador (otros incluyen señal, abreviatura, verbosa, sin formato, lectura o escritura). Aquí, escriba es el valor del calificador.

El siguiente comando realmente muestra las llamadas al sistema para imprimir la salida df en la salida estándar.

$ sudo strace -e trace=write df -h

write(1, "Filesystem      Size  Used Avail"..., 49Filesystem      Size  Used Avail Use% Mounted on
) = 49
write(1, "udev            3.9G     0  3.9G"..., 43udev            3.9G     0  3.9G   0% /dev
) = 43
write(1, "tmpfs           788M  9.6M  779M"..., 43tmpfs           788M  9.6M  779M   2% /run
) = 43
write(1, "/dev/sda10      324G  252G   56G"..., 40/dev/sda10      324G  252G   56G  82% /
) = 40
write(1, "tmpfs           3.9G  104M  3.8G"..., 47tmpfs           3.9G  104M  3.8G   3% /dev/shm
) = 47
write(1, "tmpfs           5.0M  4.0K  5.0M"..., 48tmpfs           5.0M  4.0K  5.0M   1% /run/lock
) = 48
write(1, "tmpfs           3.9G     0  3.9G"..., 53tmpfs           3.9G     0  3.9G   0% /sys/fs/cgroup
) = 53
write(1, "cgmfs           100K     0  100K"..., 56cgmfs           100K     0  100K   0% /run/cgmanager/fs
) = 56
write(1, "tmpfs           788M   28K  788M"..., 53tmpfs           788M   28K  788M   1% /run/user/1000
) = 53
+++ exited with 0 +++

A continuación, se muestran algunos comandos adicionales sobre el calificador de seguimiento.

$ sudo strace -e trace=open,close df -h
$ sudo strace -e trace=open,close,read,write df -h
$ sudo strace -e trace=all df -h	

8. Rastrear llamadas al sistema en función de una determinada condición

Veamos cómo rastrear las llamadas al sistema relacionadas con una clase determinada de eventos. Este comando se puede utilizar para rastrear todas las llamadas al sistema relacionadas con la gestión de procesos.

$ sudo strace -q -e trace=process df -h	

execve("/bin/df", ["df", "-h"], [/* 17 vars */]) = 0
arch_prctl(ARCH_SET_FS, 0x7fe2222ff700) = 0
Filesystem      Size  Used Avail Use% Mounted on
udev            3.9G     0  3.9G   0% /dev
tmpfs           788M  9.6M  779M   2% /run
/dev/sda10      324G  252G   56G  82% /
tmpfs           3.9G  104M  3.8G   3% /dev/shm
tmpfs           5.0M  4.0K  5.0M   1% /run/lock
tmpfs           3.9G     0  3.9G   0% /sys/fs/cgroup
cgmfs           100K     0  100K   0% /run/cgmanager/fs
tmpfs           788M   28K  788M   1% /run/user/1000
exit_group(0)                           = ?
+++ exited with 0 +++

A continuación, para rastrear todas las llamadas al sistema que toman un nombre de archivo como argumento, ejecute este comando.

$ sudo strace -q  -e trace=file df -h

execve("/bin/df", ["df", "-h"], [/* 17 vars */]) = 0
access("/etc/ld.so.nohwcap", F_OK)      = -1 ENOENT (No such file or directory)
access("/etc/ld.so.preload", R_OK)      = -1 ENOENT (No such file or directory)
open("/etc/ld.so.cache", O_RDONLY|O_CLOEXEC) = 3
access("/etc/ld.so.nohwcap", F_OK)      = -1 ENOENT (No such file or directory)
open("/lib/x86_64-linux-gnu/libc.so.6", O_RDONLY|O_CLOEXEC) = 3
open("/usr/lib/locale/locale-archive", O_RDONLY|O_CLOEXEC) = 3
open("/usr/share/locale/locale.alias", O_RDONLY|O_CLOEXEC) = 3
...

Para rastrear todas las llamadas al sistema que involucran mapeo de memoria, escriba.

$ sudo strace -q -e trace=memory df -h	

brk(NULL)                               = 0x77a000
mmap(NULL, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7fe8f4658000
mmap(NULL, 147662, PROT_READ, MAP_PRIVATE, 3, 0) = 0x7fe8f4633000
mmap(NULL, 3971488, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x7fe8f406b000
mprotect(0x7fe8f422b000, 2097152, PROT_NONE) = 0
mmap(0x7fe8f442b000, 24576, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x1c0000) = 0x7fe8f442b000
mmap(0x7fe8f4431000, 14752, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = 0x7fe8f4431000
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7fe8f4632000
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7fe8f4631000
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7fe8f4630000
mprotect(0x7fe8f442b000, 16384, PROT_READ) = 0
mprotect(0x616000, 4096, PROT_READ)     = 0
mprotect(0x7fe8f465a000, 4096, PROT_READ) = 0
munmap(0x7fe8f4633000, 147662)          = 0
mmap(NULL, 2981280, PROT_READ, MAP_PRIVATE, 3, 0) = 0x7fe8f3d93000
brk(NULL)                               = 0x77a000
brk(0x79b000)                           = 0x79b000
mmap(NULL, 619, PROT_READ, MAP_PRIVATE, 3, 0) = 0x7fe8f4657000
mmap(NULL, 26258, PROT_READ, MAP_SHARED, 3, 0) = 0x7fe8f4650000
Filesystem      Size  Used Avail Use% Mounted on
udev            3.9G     0  3.9G   0% /dev
tmpfs           788M  9.6M  779M   2% /run
/dev/sda10      324G  252G   56G  82% /
tmpfs           3.9G  104M  3.8G   3% /dev/shm
tmpfs           5.0M  4.0K  5.0M   1% /run/lock
tmpfs           3.9G     0  3.9G   0% /sys/fs/cgroup
cgmfs           100K     0  100K   0% /run/cgmanager/fs
tmpfs           788M   28K  788M   1% /run/user/1000
+++ exited with 0 +++

Puede rastrear todas las llamadas al sistema relacionadas con la red y las señales.

$ sudo strace -e trace=network df -h
$ sudo strace -e trace=signal df -h

9. Redirigir la salida del seguimiento a un archivo

Para escribir los mensajes de seguimiento enviados a error estándar en un archivo, use la opción -o . Esto significa que solo la salida del comando se imprime en la pantalla como se muestra a continuación.

$ sudo strace -o df_debug.txt df -h

Filesystem      Size  Used Avail Use% Mounted on
udev            3.9G     0  3.9G   0% /dev
tmpfs           788M  9.6M  779M   2% /run
/dev/sda10      324G  252G   56G  82% /
tmpfs           3.9G  104M  3.8G   3% /dev/shm
tmpfs           5.0M  4.0K  5.0M   1% /run/lock
tmpfs           3.9G     0  3.9G   0% /sys/fs/cgroup
cgmfs           100K     0  100K   0% /run/cgmanager/fs
tmpfs           788M   28K  788M   1% /run/user/1000

Para revisar el archivo, use el comando cat.

$ cat df_debug.txt 

10. Muestre algunos resultados de depuración de Strace

Para mostrar información de depuración para la herramienta strace, use la marca -d .

$ strace -d df -h

Para obtener información adicional, consulte la página de manual de strace.

$ man strace

Lea también estos útiles artículos relacionados:

  1. 20 herramientas de línea de comandos para supervisar el rendimiento de Linux
  2. Sysdig: una potente herramienta de supervisión y solución de problemas del sistema para Linux
  3. Cómo rastrear la ejecución de comandos en el script de Shell con rastreo de Shell
  4. BCC: herramientas de seguimiento dinámico para la supervisión del rendimiento de Linux, redes y más

En conclusión, strace es una herramienta extraordinaria para diagnosticar la (s) causa (s) de fallas del programa: es una herramienta de depuración y resolución de problemas poderosa. Es prácticamente útil para administradores de sistemas, programadores y piratas informáticos experimentados. Para compartir cualquier opinión sobre este artículo, utilice el formulario de comentarios a continuación.