NAME

Proc::WaitStat - Interpret and act on wait() status values

SYNOPSIS

    $description = waitstat $?;
    exit waitstat_reuse $?;
    waitstat_die $?, 'program-name';
    close_die COMMAND, 'program-name';

DESCRIPTION

This module contains functions for interpreting and acting on wait status values.

Nothing is exported by default.

waitstat wait-status

Returns a string representation of wait() status value wait-status. Values returned are like "0" and "64" and "killed (SIGHUP)".

This function is prototyped to take a single scalar argument.

waitstat_reuse wait-status

Turn wait-status into a value which can be passed to exit, converted in the same manner the shell uses. If wait-status indicates a normal exit, return the exit value. If wait-status instead indicates death by signal, return 128 plus the signal number.

This function is prototyped to take a single scalar argument.

waitstat_die wait-status program-name

die() if wait-status is non-zero (mentioning program-name as the source of the error).

This function is prototyped to take two scalar arguments.

close_die filehandle name

Close filehandle, if that fails die() with an appropriate message which refers to name. This handles failed closings of both programs and files properly.

This function is prototyped to take a filehandle (actually, a glob ref) and a scalar.

EXAMPLES

    close SENDMAIL;
    exit if $? == 0;
    log "sendmail failure: ", waitstat $?;
    exit EX_TEMPFAIL;

    $pid == waitpid $pid, 0 or croak "Failed to reap $pid: $!";
    exit waitstat_reuse $?;

    $output = `some-program -with args`;
    waitstat_die $?, 'some-program';
    print "Output from some-process:\n", $output;

    open PROGRAM, '| post-processor' or die "Can't fork: $!";
    while (<IN>) {
        print PROGRAM pre_process $_
            or die "Error writing to post-processor: $!";
    }
    # This handles both flush failures at close time and a non-zero exit
    # from the subprocess.
    close_die PROGRAM, 'post-processor';

AUTHOR

Roderick Schertler <roderick@argon.org>

SEE ALSO

perl(1), IPC::Signal(3pm).