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TRUSS(1) General Commands Manual TRUSS(1) NAME truss -- trace system calls SYNOPSIS truss [-facedDS] [-o file] [-s strsize] -p pid truss [-facedDS] [-o file] [-s strsize] command [args] DESCRIPTION The truss utility traces the system calls called by the specified process or program. Output is to the specified output file, or stan- dard error by default. It does this by stopping and restarting the process being monitored via ptrace(2). The options are as follows: -f Trace descendants of the original traced process created by fork(2), vfork(2), etc. -a Show the argument strings that are passed in each execve(2) system call. -c Do not display individual system calls. Instead, before exit- ing, print a summary containing for each system call: the total system time used, the number of times the call was invoked, and the number of times the call returned with an error. -e Show the environment strings that are passed in each execve(2) system call. -d Include timestamps in the output showing the time elapsed since the trace was started. -D Include timestamps in the output showing the time elapsed since the last recorded event. -S Do not display information about signals received by the process. (Normally, truss displays signal as well as system call events.) -o file Print the output to the specified file instead of standard er- ror. -s strsize Display strings using at most strsize characters. If the buffer is larger, "..." will be displayed at the end of the string. The default strsize is 32. -p pid Follow the process specified by pid instead of a new command. command [args] Execute command and trace the system calls of it. (The -p and command options are mutually exclusive.) EXAMPLES # Follow the system calls used in echoing "hello" $ truss /bin/echo hello # Do the same, but put the output into a file $ truss -o /tmp/truss.out /bin/echo hello # Follow an already-running process $ truss -p 34 SEE ALSO kdump(1), ktrace(1), ptrace(2) HISTORY The truss command was written by Sean Eric Fagan for FreeBSD. It was modeled after similar commands available for System V Release 4 and SunOS. FreeBSD 9.1 May 12, 2009 TRUSS(1)
NAME | SYNOPSIS | DESCRIPTION | EXAMPLES | SEE ALSO | HISTORY
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