NAME

IPC::System::Simple - Call system() commands with a minimum of fuss

SYNOPSIS

use IPC::System::Simple qw(run);

run("foo");

run("foo",@args);

my $exit_value = run([0..5], "foo", @args);

DESCRIPTION

Calling Perl's in-built system() function is easy, but checking the results can be hard. IPC::System::Simple aims to make life easy for the common cases of calling system.

IPC::System::Simple provides a single subroutine, called run, that executes a command using the same semantics is Perl's built-in system:

use IPC::System::Simple qw(run);

run("cat *.txt");		# Execute command via the shell
run("cat","/etc/motd");		# Execute command without shell

In the case where the command returns an unexpected status, run will throw an exception, which is not caught will terminate your program with an error.

Capturing an the exception is easy:

eval {
	run("cat *.txt");
};

if ($@) {
	print "Something went wrong - $@\n";
}

See the diagnostics section below for more details.

IPC::System::Simple considers the following to be unexpected, and worthy of exception:

• Failing to start entirely (eg, command not found, permission denied).

• Returning an exit value other than zero (but see below).

• Being killed by a signal.

You may specify a range of values which are considered acceptable return values by passing an array reference as the first argument:

run( [0..5], "cat *.txt");	# Exit values 0-5 are OK

run( [0..255], "cat *.txt");	# Any exit value is OK

The run subroutine returns the exit value of the process:

my $exit_value = run( [0..5], "cat *.txt");

print "Program exited with value $exit_value\n";

DIAGNOSTICS

IPC::System::Simple::run called with no arguments

You attempted to call run but did not provide any arguments at all.

IPC::System::Simple::run called with no command

You called run with a list of acceptable exit values, but no actual command.

"%s" failed to start: "%s"

The command specified did not even start. It may not exist, or you may not have permission to use it. The reason it could not start (as determined from $!) will be provided.

"%s" unexpectedly returned exit value %d"

The command ran successful, but returned an exit value we did not expect. The value returned is reported.

"%s" died to signal "%s" (%d)

The command was killed by a signal. The name of the signal will be reported, or UNKNOWN if it cannot be determined. The signal number is always reported.

Internal error in IPC::System::Simple - "%s" ran without exit value or signal"

You've found a bug in IPC::System::Simple. It knows your command ran successful, but doesn't know how or why it stopped. Please report this error using the submission mechanism described in BUGS below.

BUGS

Reporting of core-dumps is not yet implemented.

WIFSTOPPED status is not checked.

This modules relies upon a number of POSIX macros (WIFEXITED WEXITSTATUS WIFSIGNALED WTERMSIG) which are normally only found on Unix-flavoured systems. This will be fixed ASAP.

Please report bugs to http://rt.cpan.org/Public/Dist/Display.html?Name=IPC-System-Simple .

SEE ALSO

POSIX IPC::Run::Simple

AUTHOR

Paul Fenwick <pjf@cpan.org>

COPYRIGHT AND LICENSE

Copyright (C) 2006 by Paul Fenwick

This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself, either Perl version 5.8.7 or, at your option, any later version of Perl 5 you may have available.

cpanm IPC::System::Simple

perl -MCPAN -e shell
install IPC::System::Simple