Strace

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⇤ ← Revision 1 as of 2006-05-01 21:44:34 →
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Comment: Using strace
← Revision 7 as of 2008-06-25 17:25:32 → ⇥
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[[Include(Debugging/Header)]]
||<tablestyle="float:right; font-size: 0.9em; width:30%; background:#F1F1ED; background-image: url('https://librarian.launchpad.net/1812570/bugsquad.png'); background-repeat: no-repeat; background-position: 98% 0.5ex; margin: 0 0 1em 1em; padding: 0.5em;">'''Contents'''[[BR]][[TableOfContents]]||
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strace -Ff -tt <program> <arguments> 2>&1 | tee strace.log strace -Ff -tt <program> <arguments> 2>&1 | tee strace-<program>.log
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 1. Attach the complete output from strace, contained in strace.log, in your bug report.  1. Attach the complete output from strace, contained in strace-<program>.log, in your bug report.

= Already running programs =

You may want to run strace on an already running program. This could be because strace logs too many things before you can reproduce a crash. Or, it could be because you are trying to find out what a program is doing in an infinite loop.

 1. Make sure strace is installed. {{{
apt-get install strace
}}}
 1. Find the process ID of <program>: {{{
pidof <program>
}}}
 1. Start strace with the process ID: {{{
strace -Ff -tt -p <PID> 2>&1 | tee strace-<program>.log
}}}
 1. Perform any actions necessary to reproduce the bug.
 1. You may have to hit Control-C to get strace to detach from a running program.
 1. Attach the complete output from strace, contained in strace-<program>.log, in your bug report.
----
CategoryDebugging CategoryBugSquad

Include(Debugging/Header)

Sometimes, a program starts behaving errantly. It gives incorrect output on its input, it doesn't print anything at all, or even hangs. Under a Linux-based system, every userspace process has to interact with its environment through the kernel. And it does this by invoking system calls.

Strace is a utility that intercepts and logs these system calls. In this way, you can watch how a program interacts with the system, which is useful for tracking down behavioural issues.

Generation

  1. Make sure strace is installed. 

    apt-get install strace

  2. Start the program under control of strace: 

    strace -Ff -tt <program> <arguments> 2>&1 | tee strace-<program>.log
  3. The program will start. Perform any actions necessary to reproduce the crash

  4. Attach the complete output from strace, contained in strace-<program>.log, in your bug report.

Already running programs

You may want to run strace on an already running program. This could be because strace logs too many things before you can reproduce a crash. Or, it could be because you are trying to find out what a program is doing in an infinite loop.

  1. Make sure strace is installed. 

    apt-get install strace

  2. Find the process ID of <program>: 

    pidof <program>

  3. Start strace with the process ID: 

    strace -Ff -tt -p <PID> 2>&1 | tee strace-<program>.log
  4. Perform any actions necessary to reproduce the bug.
  5. You may have to hit Control-C to get strace to detach from a running program.

  6. Attach the complete output from strace, contained in strace-<program>.log, in your bug report.

CategoryDebugging CategoryBugSquad

Strace (last edited 2008-08-06 17:00:03 by localhost)