System information

196 System Analysis and Tuning Guide
brk(0) = 0x69e000
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) \
= 0x7f3bb553b000
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) \
= 0x7f3bb553a000
[...]
[pid 4823] rt_sigprocmask(SIG_SETMASK, [], <unfinished ...>
[pid 4822] close(4 <unfinished ...>
[pid 4823] <... rt_sigprocmask resumed> NULL, 8) = 0
[pid 4822] <... close resumed> ) = 0
[...]
[pid 4825] mprotect(0x7fc42cbbd000, 16384, PROT_READ) = 0
[pid 4825] mprotect(0x60a000, 4096, PROT_READ) = 0
[pid 4825] mprotect(0x7fc42cde4000, 4096, PROT_READ) = 0
[pid 4825] munmap(0x7fc42cda2000, 261953) = 0
[...]
[pid 4830] munmap(0x7fb1fff10000, 261953) = 0
[pid 4830] rt_sigprocmask(SIG_BLOCK, NULL, [], 8) = 0
[pid 4830] open("/dev/tty", O_RDWR|O_NONBLOCK) = 3
[pid 4830] close(3)
[...]
read(255, "\n\n# Inform the caller not only v"..., 8192) = 73
rt_sigprocmask(SIG_BLOCK, NULL, [], 8) = 0
rt_sigprocmask(SIG_BLOCK, NULL, [], 8) = 0
exit_group(0)
If you need to analyze the output of strace and the output messages are too long to
be inspected directly in the console window, use -o. In that case, unnecessary mes-
sages, such as information about attaching and detaching processes, are suppressed.
You can also suppress these messages (normally printed on the standard output) with
-q. To optionally prepend timestamps to each line with a system call, use -t:
tux@mercury:~> strace -t -o strace_sleep.txt sleep 1; more strace_sleep.txt
08:44:06 execve("/bin/sleep", ["sleep", "1"], [/* 81 vars */]) = 0
08:44:06 brk(0) = 0x606000
08:44:06 mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, \
-1, 0) = 0x7f8e78cc5000
[...]
08:44:06 close(3) = 0
08:44:06 nanosleep({1, 0}, NULL) = 0
08:44:07 close(1) = 0
08:44:07 close(2) = 0
08:44:07 exit_group(0) = ?
The behavior and output format of strace can be largely controlled. For more infor-
mation, see the relevant manual page (man 1 strace).