10 comandi Linux efficaci meno conosciuti - Parte IV

Continuando la serie Meno conosciuti, questo quarto articolo della serie ti farà conoscere alcuni utili comandi divertenti e animati. Qui entriamo nella sessione pratica, senza molta teoria.

11 Comandi Linux utili meno conosciuti – Parte I
10 comandi Linux meno conosciuti – Parte 2
10 comandi meno conosciuti per Linux – Parte 3
10 comandi Linux utili meno conosciuti - Parte V

Nel quarto articolo di questa serie che include pochi altri comandi Linux meno conosciuti, che vale la pena conoscere. Potresti essere già a conoscenza di questi comandi, senza dubbio sei un utente Linux esperto e ami l'esplorazione.

32. comando strace

strace è uno strumento di debug utilizzato principalmente per la risoluzione dei problemi in Linux. Potrebbe non essere installato per impostazione predefinita nel tuo sistema e potresti dover apt o yum il pacchetto richiesto.

Traccia l'esecuzione di un comando utilizzando il comando strace:

root@tecmint [~]# strace pwd

Uscita del campione


execve("/bin/pwd", ["pwd"], [/* 29 vars */]) = 0
brk(0)                                  = 0x728000
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f29b0df2000
access("/etc/ld.so.preload", R_OK)      = -1 ENOENT (No such file or directory)
open("/etc/ld.so.cache", O_RDONLY)      = 3
fstat(3, {st_mode=S_IFREG|0644, st_size=38427, ...}) = 0
mmap(NULL, 38427, PROT_READ, MAP_PRIVATE, 3, 0) = 0x7f29b0de8000
close(3)                                = 0
open("/lib64/libc.so.6", O_RDONLY)      = 3
read(3, "7ELFexecve("/bin/pwd", ["pwd"], [/* 29 vars */]) = 0
brk(0)                                  = 0x728000
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f29b0df2000
access("/etc/ld.so.preload", R_OK)      = -1 ENOENT (No such file or directory)
open("/etc/ld.so.cache", O_RDONLY)      = 3
fstat(3, {st_mode=S_IFREG|0644, st_size=38427, ...}) = 0
mmap(NULL, 38427, PROT_READ, MAP_PRIVATE, 3, 0) = 0x7f29b0de8000
close(3)                                = 0
open("/lib64/libc.so.6", O_RDONLY)      = 3
read(3, "\177ELF\2\1\1\3\0\0\0\0\0\0\0\0\3\0&gt;\0\1\0\0\0\360\355\1I;\0\0\0"..., 832) = 832
fstat(3, {st_mode=S_IFREG|0755, st_size=1922152, ...}) = 0
mmap(0x3b49000000, 3745960, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x3b49000000
mprotect(0x3b4918a000, 2093056, PROT_NONE) = 0
mmap(0x3b49389000, 20480, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x189000) = 0x3b49389000
mmap(0x3b4938e000, 18600, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = 0x3b4938e000
close(3)                                = 0
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f29b0de7000
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f29b0de6000
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f29b0de5000
....
execve("/bin/pwd", ["pwd"], [/* 29 vars */]) = 0
brk(0)                                  = 0x728000
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f29b0df2000
access("/etc/ld.so.preload", R_OK)      = -1 ENOENT (No such file or directory)
open("/etc/ld.so.cache", O_RDONLY)      = 3
fstat(3, {st_mode=S_IFREG|0644, st_size=38427, ...}) = 0
mmap(NULL, 38427, PROT_READ, MAP_PRIVATE, 3, 0) = 0x7f29b0de8000
close(3)                                = 0
open("/lib64/libc.so.6", O_RDONLY)      = 3
read(3, "\177ELF\2\1\1\3\0\0\0\0\0\0\0\0\3\0&gt;\0\1\0\0\0\360\355\1I;\0\0\0"..., 832) = 832
fstat(3, {st_mode=S_IFREG|0755, st_size=1922152, ...}) = 0
mmap(0x3b49000000, 3745960, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x3b49000000
mprotect(0x3b4918a000, 2093056, PROT_NONE) = 0
mmap(0x3b49389000, 20480, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x189000) = 0x3b49389000
mmap(0x3b4938e000, 18600, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = 0x3b4938e000
close(3)                                = 0
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f29b0de7000
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f29b0de6000
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f29b0de5000
....
execve("/bin/pwd", ["pwd"], [/* 29 vars */]) = 0
brk(0)                                  = 0x728000
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f29b0df2000
access("/etc/ld.so.preload", R_OK)      = -1 ENOENT (No such file or directory)
open("/etc/ld.so.cache", O_RDONLY)      = 3
fstat(3, {st_mode=S_IFREG|0644, st_size=38427, ...}) = 0
mmap(NULL, 38427, PROT_READ, MAP_PRIVATE, 3, 0) = 0x7f29b0de8000
close(3)                                = 0
open("/lib64/libc.so.6", O_RDONLY)      = 3
read(3, "\177ELF\2\1\1\3\0\0\0\0\0\0\0\0\3\0&gt;\0\1\0\0\0\360\355\1I;\0\0\0"..., 832) = 832
fstat(3, {st_mode=S_IFREG|0755, st_size=1922152, ...}) = 0
mmap(0x3b49000000, 3745960, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x3b49000000
mprotect(0x3b4918a000, 2093056, PROT_NONE) = 0
mmap(0x3b49389000, 20480, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x189000) = 0x3b49389000
mmap(0x3b4938e000, 18600, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = 0x3b4938e000
close(3)                                = 0
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f29b0de7000
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f29b0de6000
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f29b0de5000
....
execve("/bin/pwd", ["pwd"], [/* 29 vars */]) = 0
brk(0)                                  = 0x728000
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f29b0df2000
access("/etc/ld.so.preload", R_OK)      = -1 ENOENT (No such file or directory)
open("/etc/ld.so.cache", O_RDONLY)      = 3
fstat(3, {st_mode=S_IFREG|0644, st_size=38427, ...}) = 0
mmap(NULL, 38427, PROT_READ, MAP_PRIVATE, 3, 0) = 0x7f29b0de8000
close(3)                                = 0
open("/lib64/libc.so.6", O_RDONLY)      = 3
read(3, "\177ELF\2\1\1\3\0\0\0\0\0\0\0\0\3\0&gt;\0\1\0\0\0\360\355\1I;\0\0\0"..., 832) = 832
fstat(3, {st_mode=S_IFREG|0755, st_size=1922152, ...}) = 0
mmap(0x3b49000000, 3745960, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x3b49000000
mprotect(0x3b4918a000, 2093056, PROT_NONE) = 0
mmap(0x3b49389000, 20480, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x189000) = 0x3b49389000
mmap(0x3b4938e000, 18600, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = 0x3b4938e000
close(3)                                = 0
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f29b0de7000
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f29b0de6000
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f29b0de5000
....
execve("/bin/pwd", ["pwd"], [/* 29 vars */]) = 0
brk(0)                                  = 0x728000
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f29b0df2000
access("/etc/ld.so.preload", R_OK)      = -1 ENOENT (No such file or directory)
open("/etc/ld.so.cache", O_RDONLY)      = 3
fstat(3, {st_mode=S_IFREG|0644, st_size=38427, ...}) = 0
mmap(NULL, 38427, PROT_READ, MAP_PRIVATE, 3, 0) = 0x7f29b0de8000
close(3)                                = 0
open("/lib64/libc.so.6", O_RDONLY)      = 3
read(3, "\177ELF\2\1\1\3\0\0\0\0\0\0\0\0\3\0&gt;\0\1\0\0\0\360\355\1I;\0\0\0"..., 832) = 832
fstat(3, {st_mode=S_IFREG|0755, st_size=1922152, ...}) = 0
mmap(0x3b49000000, 3745960, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x3b49000000
mprotect(0x3b4918a000, 2093056, PROT_NONE) = 0
mmap(0x3b49389000, 20480, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x189000) = 0x3b49389000
mmap(0x3b4938e000, 18600, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = 0x3b4938e000
close(3)                                = 0
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f29b0de7000
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f29b0de6000
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f29b0de5000
....
execve("/bin/pwd", ["pwd"], [/* 29 vars */]) = 0
brk(0)                                  = 0x728000
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f29b0df2000
access("/etc/ld.so.preload", R_OK)      = -1 ENOENT (No such file or directory)
open("/etc/ld.so.cache", O_RDONLY)      = 3
fstat(3, {st_mode=S_IFREG|0644, st_size=38427, ...}) = 0
mmap(NULL, 38427, PROT_READ, MAP_PRIVATE, 3, 0) = 0x7f29b0de8000
close(3)                                = 0
open("/lib64/libc.so.6", O_RDONLY)      = 3
read(3, "\177ELF\2\1\1\3\0\0\0\0\0\0\0\0\3\0&gt;\0\1\0\0\0\360\355\1I;\0\0\0"..., 832) = 832
fstat(3, {st_mode=S_IFREG|0755, st_size=1922152, ...}) = 0
mmap(0x3b49000000, 3745960, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x3b49000000
mprotect(0x3b4918a000, 2093056, PROT_NONE) = 0
mmap(0x3b49389000, 20480, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x189000) = 0x3b49389000
mmap(0x3b4938e000, 18600, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = 0x3b4938e000
close(3)                                = 0
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f29b0de7000
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f29b0de6000
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f29b0de5000
....
execve("/bin/pwd", ["pwd"], [/* 29 vars */]) = 0
brk(0)                                  = 0x728000
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f29b0df2000
access("/etc/ld.so.preload", R_OK)      = -1 ENOENT (No such file or directory)
open("/etc/ld.so.cache", O_RDONLY)      = 3
fstat(3, {st_mode=S_IFREG|0644, st_size=38427, ...}) = 0
mmap(NULL, 38427, PROT_READ, MAP_PRIVATE, 3, 0) = 0x7f29b0de8000
close(3)                                = 0
open("/lib64/libc.so.6", O_RDONLY)      = 3
read(3, "\177ELF\2\1\1\3\0\0\0\0\0\0\0\0\3\0&gt;\0\1\0\0\0\360\355\1I;\0\0\0"..., 832) = 832
fstat(3, {st_mode=S_IFREG|0755, st_size=1922152, ...}) = 0
mmap(0x3b49000000, 3745960, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x3b49000000
mprotect(0x3b4918a000, 2093056, PROT_NONE) = 0
mmap(0x3b49389000, 20480, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x189000) = 0x3b49389000
mmap(0x3b4938e000, 18600, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = 0x3b4938e000
close(3)                                = 0
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f29b0de7000
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f29b0de6000
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f29b0de5000
....
execve("/bin/pwd", ["pwd"], [/* 29 vars */]) = 0
brk(0)                                  = 0x728000
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f29b0df2000
access("/etc/ld.so.preload", R_OK)      = -1 ENOENT (No such file or directory)
open("/etc/ld.so.cache", O_RDONLY)      = 3
fstat(3, {st_mode=S_IFREG|0644, st_size=38427, ...}) = 0
mmap(NULL, 38427, PROT_READ, MAP_PRIVATE, 3, 0) = 0x7f29b0de8000
close(3)                                = 0
open("/lib64/libc.so.6", O_RDONLY)      = 3
read(3, "\177ELF\2\1\1\3\0\0\0\0\0\0\0\0\3\0&gt;\0\1\0\0\0\360\355\1I;\0\0\0"..., 832) = 832
fstat(3, {st_mode=S_IFREG|0755, st_size=1922152, ...}) = 0
mmap(0x3b49000000, 3745960, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x3b49000000
mprotect(0x3b4918a000, 2093056, PROT_NONE) = 0
mmap(0x3b49389000, 20480, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x189000) = 0x3b49389000
mmap(0x3b4938e000, 18600, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = 0x3b4938e000
close(3)                                = 0
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f29b0de7000
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f29b0de6000
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f29b0de5000
....
execve("/bin/pwd", ["pwd"], [/* 29 vars */]) = 0
brk(0)                                  = 0x728000
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f29b0df2000
access("/etc/ld.so.preload", R_OK)      = -1 ENOENT (No such file or directory)
open("/etc/ld.so.cache", O_RDONLY)      = 3
fstat(3, {st_mode=S_IFREG|0644, st_size=38427, ...}) = 0
mmap(NULL, 38427, PROT_READ, MAP_PRIVATE, 3, 0) = 0x7f29b0de8000
close(3)                                = 0
open("/lib64/libc.so.6", O_RDONLY)      = 3
read(3, "\177ELF\2\1\1\3\0\0\0\0\0\0\0\0\3\0&gt;\0\1\0\0\0\360\355\1I;\0\0\0"..., 832) = 832
fstat(3, {st_mode=S_IFREG|0755, st_size=1922152, ...}) = 0
mmap(0x3b49000000, 3745960, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x3b49000000
mprotect(0x3b4918a000, 2093056, PROT_NONE) = 0
mmap(0x3b49389000, 20480, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x189000) = 0x3b49389000
mmap(0x3b4938e000, 18600, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = 0x3b4938e000
close(3)                                = 0
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f29b0de7000
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f29b0de6000
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f29b0de5000
....
execve("/bin/pwd", ["pwd"], [/* 29 vars */]) = 0
brk(0)                                  = 0x728000
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f29b0df2000
access("/etc/ld.so.preload", R_OK)      = -1 ENOENT (No such file or directory)
open("/etc/ld.so.cache", O_RDONLY)      = 3
fstat(3, {st_mode=S_IFREG|0644, st_size=38427, ...}) = 0
mmap(NULL, 38427, PROT_READ, MAP_PRIVATE, 3, 0) = 0x7f29b0de8000
close(3)                                = 0
open("/lib64/libc.so.6", O_RDONLY)      = 3
read(3, "\177ELF\2\1\1\3\0\0\0\0\0\0\0\0\3\0&gt;\0\1\0\0\0\360\355\1I;\0\0\0"..., 832) = 832
fstat(3, {st_mode=S_IFREG|0755, st_size=1922152, ...}) = 0
mmap(0x3b49000000, 3745960, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x3b49000000
mprotect(0x3b4918a000, 2093056, PROT_NONE) = 0
mmap(0x3b49389000, 20480, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x189000) = 0x3b49389000
mmap(0x3b4938e000, 18600, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = 0x3b4938e000
close(3)                                = 0
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f29b0de7000
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f29b0de6000
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f29b0de5000
....
execve("/bin/pwd", ["pwd"], [/* 29 vars */]) = 0
brk(0)                                  = 0x728000
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f29b0df2000
access("/etc/ld.so.preload", R_OK)      = -1 ENOENT (No such file or directory)
open("/etc/ld.so.cache", O_RDONLY)      = 3
fstat(3, {st_mode=S_IFREG|0644, st_size=38427, ...}) = 0
mmap(NULL, 38427, PROT_READ, MAP_PRIVATE, 3, 0) = 0x7f29b0de8000
close(3)                                = 0
open("/lib64/libc.so.6", O_RDONLY)      = 3
read(3, "\177ELF\2\1\1\3\0\0\0\0\0\0\0\0\3\0&gt;\0\1\0\0\0\360\355\1I;\0\0\0"..., 832) = 832
fstat(3, {st_mode=S_IFREG|0755, st_size=1922152, ...}) = 0
mmap(0x3b49000000, 3745960, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x3b49000000
mprotect(0x3b4918a000, 2093056, PROT_NONE) = 0
mmap(0x3b49389000, 20480, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x189000) = 0x3b49389000
mmap(0x3b4938e000, 18600, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = 0x3b4938e000
close(3)                                = 0
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f29b0de7000
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f29b0de6000
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f29b0de5000
....
execve("/bin/pwd", ["pwd"], [/* 29 vars */]) = 0
brk(0)                                  = 0x728000
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f29b0df2000
access("/etc/ld.so.preload", R_OK)      = -1 ENOENT (No such file or directory)
open("/etc/ld.so.cache", O_RDONLY)      = 3
fstat(3, {st_mode=S_IFREG|0644, st_size=38427, ...}) = 0
mmap(NULL, 38427, PROT_READ, MAP_PRIVATE, 3, 0) = 0x7f29b0de8000
close(3)                                = 0
open("/lib64/libc.so.6", O_RDONLY)      = 3
read(3, "\177ELF\2\1\1\3\0\0\0\0\0\0\0\0\3\0&gt;\0\1\0\0\0\360\355\1I;\0\0\0"..., 832) = 832
fstat(3, {st_mode=S_IFREG|0755, st_size=1922152, ...}) = 0
mmap(0x3b49000000, 3745960, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x3b49000000
mprotect(0x3b4918a000, 2093056, PROT_NONE) = 0
mmap(0x3b49389000, 20480, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x189000) = 0x3b49389000
mmap(0x3b4938e000, 18600, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = 0x3b4938e000
close(3)                                = 0
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f29b0de7000
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f29b0de6000
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f29b0de5000
....
execve("/bin/pwd", ["pwd"], [/* 29 vars */]) = 0
brk(0)                                  = 0x728000
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f29b0df2000
access("/etc/ld.so.preload", R_OK)      = -1 ENOENT (No such file or directory)
open("/etc/ld.so.cache", O_RDONLY)      = 3
fstat(3, {st_mode=S_IFREG|0644, st_size=38427, ...}) = 0
mmap(NULL, 38427, PROT_READ, MAP_PRIVATE, 3, 0) = 0x7f29b0de8000
close(3)                                = 0
open("/lib64/libc.so.6", O_RDONLY)      = 3
read(3, "\177ELF\2\1\1\3\0\0\0\0\0\0\0\0\3\0&gt;\0\1\0\0\0\360\355\1I;\0\0\0"..., 832) = 832
fstat(3, {st_mode=S_IFREG|0755, st_size=1922152, ...}) = 0
mmap(0x3b49000000, 3745960, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x3b49000000
mprotect(0x3b4918a000, 2093056, PROT_NONE) = 0
mmap(0x3b49389000, 20480, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x189000) = 0x3b49389000
mmap(0x3b4938e000, 18600, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = 0x3b4938e000
close(3)                                = 0
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f29b0de7000
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f29b0de6000
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f29b0de5000
....
execve("/bin/pwd", ["pwd"], [/* 29 vars */]) = 0
brk(0)                                  = 0x728000
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f29b0df2000
access("/etc/ld.so.preload", R_OK)      = -1 ENOENT (No such file or directory)
open("/etc/ld.so.cache", O_RDONLY)      = 3
fstat(3, {st_mode=S_IFREG|0644, st_size=38427, ...}) = 0
mmap(NULL, 38427, PROT_READ, MAP_PRIVATE, 3, 0) = 0x7f29b0de8000
close(3)                                = 0
open("/lib64/libc.so.6", O_RDONLY)      = 3
read(3, "\177ELF\2\1\1\3\0\0\0\0\0\0\0\0\3\0&gt;\0\1\0\0\0\360\355\1I;\0\0\0"..., 832) = 832
fstat(3, {st_mode=S_IFREG|0755, st_size=1922152, ...}) = 0
mmap(0x3b49000000, 3745960, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x3b49000000
mprotect(0x3b4918a000, 2093056, PROT_NONE) = 0
mmap(0x3b49389000, 20480, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x189000) = 0x3b49389000
mmap(0x3b4938e000, 18600, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = 0x3b4938e000
close(3)                                = 0
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f29b0de7000
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f29b0de6000
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f29b0de5000
....
execve("/bin/pwd", ["pwd"], [/* 29 vars */]) = 0
brk(0)                                  = 0x728000
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f29b0df2000
access("/etc/ld.so.preload", R_OK)      = -1 ENOENT (No such file or directory)
open("/etc/ld.so.cache", O_RDONLY)      = 3
fstat(3, {st_mode=S_IFREG|0644, st_size=38427, ...}) = 0
mmap(NULL, 38427, PROT_READ, MAP_PRIVATE, 3, 0) = 0x7f29b0de8000
close(3)                                = 0
open("/lib64/libc.so.6", O_RDONLY)      = 3
read(3, "\177ELF\2\1\1\3\0\0\0\0\0\0\0\0\3\0&gt;\0\1\0\0\0\360\355\1I;\0\0\0"..., 832) = 832
fstat(3, {st_mode=S_IFREG|0755, st_size=1922152, ...}) = 0
mmap(0x3b49000000, 3745960, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x3b49000000
mprotect(0x3b4918a000, 2093056, PROT_NONE) = 0
mmap(0x3b49389000, 20480, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x189000) = 0x3b49389000
mmap(0x3b4938e000, 18600, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = 0x3b4938e000
close(3)                                = 0
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f29b0de7000
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f29b0de6000
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f29b0de5000
....
execve("/bin/pwd", ["pwd"], [/* 29 vars */]) = 0
brk(0)                                  = 0x728000
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f29b0df2000
access("/etc/ld.so.preload", R_OK)      = -1 ENOENT (No such file or directory)
open("/etc/ld.so.cache", O_RDONLY)      = 3
fstat(3, {st_mode=S_IFREG|0644, st_size=38427, ...}) = 0
mmap(NULL, 38427, PROT_READ, MAP_PRIVATE, 3, 0) = 0x7f29b0de8000
close(3)                                = 0
open("/lib64/libc.so.6", O_RDONLY)      = 3
read(3, "\177ELF\2\1\1\3\0\0\0\0\0\0\0\0\3\0&gt;\0\1\0\0\0\360\355\1I;\0\0\0"..., 832) = 832
fstat(3, {st_mode=S_IFREG|0755, st_size=1922152, ...}) = 0
mmap(0x3b49000000, 3745960, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x3b49000000
mprotect(0x3b4918a000, 2093056, PROT_NONE) = 0
mmap(0x3b49389000, 20480, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x189000) = 0x3b49389000
mmap(0x3b4938e000, 18600, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = 0x3b4938e000
close(3)                                = 0
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f29b0de7000
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f29b0de6000
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f29b0de5000
....


Il comando strace accetta molti argomenti e ha molte opzioni. Fare riferimento alla pagina man per informazioni dettagliate.
33. disown -a && esci dal comando
La maggior parte degli amministratori di sistema utilizza il comando screen per controllare i lavori in esecuzione sullo sfondo del terminale. Diciamo che se hai un lavoro di lunga durata e vuoi staccarti dal terminale, usi il comando schermo per farlo. Ma cosa succede se non sai come usare lo schermo, ecco che arriva il comando disown in soccorso.
Il comando disown viene utilizzato per eseguire i lavori continuamente in background anche dopo aver chiuso la sessione del terminale. La sintassi del comando disown è:
root@tecmint [~]# Command; disown -a && exit
Per scollegare nuovamente il lavoro in esecuzione da molto tempo nel terminale, utilizzare il comando jobs per trovare il numero del lavoro e quindi utilizzare disown %n dove n è il numero di lavoro. Per verificare che il lavoro sia effettivamente in esecuzione, utilizza ps o il comando top. Il comando nohup è un'alternativa al comando disown.
34. comando getconf LONG_BIT
Il comando precedente mostra l'architettura della tua macchina se è a 32 bit o a 64 bit?
root@tecmint [~]# getconf LONG_BIT

32
Scarica il Cheat Sheet della riga di comando di Linux
35. Visualizza la data sul terminale
Il comando seguente è una combinazione di diversi comandi, meglio dirlo uno script. Per una persona che lavora alla shell o al terminale, senza la GUI che vede la data corrente del sistema è un lavoro noioso. Devi digitare il comando "date" per verificare la data odierna.
Basta eseguire il comando seguente al prompt e visualizzare la data e l'ora nell'angolo in alto a destra del terminale.
root@tecmint [~]# while sleep 1;do tput sc;tput cup 0 $(($(tput cols)-29));date;tput rc;done &
36. converti comando
Durante la scrittura del tutorial, di solito ho bisogno di produrre output, molte volte in formato immagine. La combinazione di comandi sopra fa questo per me. Supponiamo che mi serva l'output del comando tree (per la directory /etc/x11) in formato immagine. Quello che ho fatto al terminale è stato:
root@tecmint:/etc/X11# tree | convert label:@- /home/avi/tree.png



L'output del comando precedente può essere visto nella posizione specificata (qui, la mia directory home) con il nome del file specificato come tree.png.
37. guarda -t -n1 “data +%T|figlet”
Ricordate la nostra descrizione del comando “figlet” nel nostro precedente articolo “20 divertenti comandi di Linux”. Questo comando è stato molto interessante, questa volta inseriremo "figlet" per mostrare l'orologio digitale animato nel terminale.
Controlla tu stesso, ricorda che devi avere figlet installato sul sistema, esegui apt o yum per installare il pacchetto richiesto.
root@tecmint [~]# watch -t -n1 "date +%T|figlet"
Uscita del campione
 _  ___    ____   ___    _____ _  _                                                                                             Fri Nov 29 10:29:34 GMT 
/ |/ _ \ _|___ \ / _ \ _|___ /| || |
| | | | (_) __) | (_) (_) |_ \| || |_
| | |_| |_ / __/ \__, |_ ___) |__   _|
|_|\___/(_)_____|  /_/(_)____/   |_|
38. Comandi host e dig
Sebbene i comandi “host” e “dig” non siano molto meno conosciuti, non sono ancora utilizzati molto frequentemente. Il comando host è l'utilità di ricerca DNS.
root@tecmint [~]# host www.google.com

www.google.com has address 173.194.66.147
www.google.com has address 173.194.66.105
www.google.com has address 173.194.66.99
www.google.com has address 173.194.66.104
www.google.com has address 173.194.66.106
www.google.com has address 173.194.66.103
www.google.com has IPv6 address 2a00:1450:400c:c03::68
root@tecmint [~]# dig www.google.com

; <<>> DiG 9.8.2rc1-RedHat-9.8.2-0.17.rc1.el6_4.6 <<>> www.google.com
;; global options: +cmd
;; Got answer:
;; ->>HEADER<
39. Comando dstat
Il dstat è uno strumento versatile, che genera statistiche relative alle risorse del sistema. Per impostazione predefinita, il tuo sistema potrebbe non avere "dstat" installato. Fai un apt o yum per installare "dstat" prima di utilizzare questo generatore di risorse di sistema molto colorato e descrittivo.
root@tecmint [~]# dstat
40. comando bind -p
Il comando "bind -p" mostrerà tutte le scorciatoie disponibili per la shell BASH.
root@tecmint [~]# bind -p
Uscita del campione
"\C-g": abort 
"\C-x\C-g": abort 
"\e\C-g": abort 
"\C-j": accept-line
"\C-m": accept-line 
alias-expand-line (not bound) 
arrow-key-prefix (not bound) 
backward-byte (not bound) 
"\C-b": backward-char 
"\eOD": backward-char 
"\e[D": backward-char 
"\e!": complete-command 
"\e/": complete-filename 
"\e@": complete-hostname 
"\e{": complete-into-braces 
"\e~": complete-username 
"\e$": complete-variable 
copy-backward-word (not bound)
copy-forward-word (not bound) 
copy-region-as-kill (not bound)
....
....
41. tocca /forcefsck
Il comando precedente creerà una cartella vuota "forcefsck", nella directory principale. Ciò costringerà il sistema Linux a controllare il file system all'avvio successivo.
root@tecmint [~]# touch /forcefsck
È tutto per ora. Voi gente amate questi "Comandi meno conosciuti" e quindi continuiamo la serie, il prossimo articolo di questa serie sarà disponibile molto presto.
Fino ad allora restate sintonizzati e connessi a Tecmint. Non dimenticare di fornire il tuo prezioso feedback nella nostra sezione commenti. Fateci un favore, mettete mi piace, condivideteci e aiutateci a diffondere.