truss(1)                                                       truss(1)

  truss

  NAME

    truss - trace system calls and signals

  SYNOPSIS

    truss [-DhpR] [-S nsteps] [-o outfile] [--] arg ...

  DESCRIPTION

    The truss(1) utility traces system calls and signals while it runs. Unless
    the -o option is given, these are written to standard error. You must
    specify one or more args. Normally, the arg is the argument vector of a
    command to trace. If the -p option is given, you can supply a list of
    process identifiers (IDs) as the args.

    The truss(1) takes the following options:

    -D
        Generate debug.

    -h
        Display help information.
    -o file
        Write output into file; without this option, output is written to
        standard error.

    -p
        Print information only about certain processes; processes are
        specified as process IDs.

    -R
        Dump registers on each event.
    -S n
        Single step for n computer instructions.

  DIAGNOSTICS

    The truss(1) utility exits with status 0 for success, and >0 if an error
    occurred.

  EXAMPLES

    To follow the system calls for an ls(1) command:

    $ truss ls /bin/truss
    tracing pid 8323077
    isatty(1) isatty returned 0
    ioctl() ioctl returned 0
    getids() getids returned 0
    stat() stat returned 0
    fstat(1, 0x2540588) fstat returned 0
    isatty(1) isatty returned 0
    isatty(1) isatty returned 0
    write(1, 0x830C60, 22) /bin/truss
    write returned 22 0x16
    exit(0) process has exited

    In this case, all calls returned 0.

  SEE ALSO

    gdb(1)

    pstat(1)