NAME
Sys::Cmd - run a system command or spawn a system processes
VERSION
0.85.2 (2016-03-11)
SYNOPSIS
use Sys::Cmd qw/run spawn/;
# Get command output, raise exception on failure:
$output = run(@cmd);
# Feed command some input, get output as lines,
# raise exception on failure:
@output = run(@cmd, { input => 'feedme' });
# Spawn and interact with a process somewhere else:
$proc = spawn( @cmd, { dir => '/' , encoding => 'iso-8859-3'} );
while (my $line = $proc->stdout->getline) {
$proc->stdin->print("thanks");
}
my @errors = $proc->stderr->getlines;
$proc->close(); # Finished talking
$proc->wait_child(); # Cleanup
# read exit information
$proc->exit(); # exit status
$proc->signal(); # signal
$proc->core(); # core dumped? (boolean)
DESCRIPTION
Sys::Cmd lets you run system commands and capture their output, or spawn
and interact with a system process through its `STDIN', `STDOUT', and
`STDERR' file handles. The following functions are exported on demand by
this module:
run( @cmd, [\%opt] ) => $output | @output
Execute `@cmd' and return what the command sent to its `STDOUT',
raising an exception in the event of error. In array context returns
a list instead of a plain string.
The first element of `@cmd' will be looked up using File::Which if
it doesn't exist as a relative file name is is a CODE reference
(UNIX only). The command input and environment can be modified with
an optional hashref containing the following key/values:
dir The working directory the command will be run in.
encoding
An string value identifying the encoding of the input/output
file-handles. Defaults to 'utf8'.
env A hashref containing key/values to be added to the current
environment at run-time. If a key has an undefined value then
the key is removed from the environment altogether.
input
A string which is fed to the command via its standard input,
which is then closed.
runx( @cmd, [\%opt] ) => $outerrput | @outerrput
The same as the `run' function but with the command's `STDERR'
output appended to the `STDOUT' output.
spawn( @cmd, [\%opt] ) => Sys::Cmd
Return a Sys::Cmd object (documented below) representing the process
running @cmd, with attributes set according to the optional \%opt
hashref. The first element of the `@cmd' array is looked up using
File::Which if it cannot be found in the file-system as a relative
file name or it is a CODE reference (UNIX only).
Sys::Cmd objects can of course be created using the standard `new'
constructor if you prefer that to the `spawn' function:
$proc = Sys::Cmd->new(
cmd => \@cmd,
dir => '/',
env => { SOME => 'VALUE' },
enc => 'iso-8859-3',
input => 'feedme',
on_exit => sub {
my $proc = shift;
print $proc->pid .' exited with '. $proc->exit;
},
);
Note that Sys::Cmd objects created this way will not lookup the command
using File::Which the way the `run', `runx' and `spawn' functions do.
Sys::Cmd uses Log::Any `debug' calls for logging purposes. An easy way
to see the output is to add `use Log::Any::Adapter 'Stdout'' in your
program.
CONSTRUCTOR
new(%args) => Sys::Cmd
Spawns a process based on %args. %args must contain at least a `cmd'
value, and optionally `encoding', `env', `dir' and `input' values as
defined as attributes below.
If an `on_exit' subref argument is provided it will be called by the
`wait_child' method, which can either be called manually or will be
automatically called when the object is destroyed.
ATTRIBUTES
All attributes are read-only.
cmd An array ref containing the command or CODE reference (UNIX only)
and its arguments.
dir The working directory the command will be run in.
encoding
An string value identifying the encoding of the input/output
file-handles. Defaults to 'utf8'.
env A hashref containing key/values to be added to the current
environment at run-time. If a key has an undefined value then the
key is removed from the environment altogether.
input
A string which is fed to the command via its standard input, which
is then closed. This is a shortcut for printing to, and closing the
command's *stdin* file-handle. An empty string will close the
command's standard input without writing to it. On some systems,
some commands may close standard input on startup, which will cause
a SIGPIPE when trying to write to it for which Sys::Cmd will warn.
pid The command's process ID.
stdin
The command's *STDIN* file handle, based on IO::Handle so you can
call print() etc methods on it. Autoflush is automatically enabled
on this handle.
stdout
The command's *STDOUT* file handle, based on IO::Handle so you can
call getline() etc methods on it.
stderr
The command's *STDERR* file handle, based on IO::Handle so you can
call getline() etc methods on it.
exit
The command's exit value, shifted by 8 (see "perldoc -f system").
Set by `wait_child()'.
signal
The signal number (if any) that terminated the command,
bitwise-added with 127 (see "perldoc -f system"). Set by
`wait_child()'.
core
A boolean indicating the process core was dumped. Set by
`wait_child()'.
METHODS
cmdline => @list | $str
In array context returns a list of the command and its arguments. In
scalar context returns a string of the command and its arguments
joined together by spaces.
close()
Close all filehandles to the child process. Note that file handles
will automaticaly be closed when the Sys::Cmd object is destroyed.
Annoyingly, this means that in the following example `$fh' will be
closed when you tried to use it:
my $fh = Sys::Cmd->new( %args )->stdout;
So you have to keep track of the Sys::Cmd object manually.
wait_child() -> $exit_value
Wait for the child to exit using waitpid, collect the exit status
and return it. This method sets the *exit*, *signal* and *core*
attributes and will also be called automatically when the Sys::Cmd
object is destroyed.
SEE ALSO
Sys::Cmd::Template
ALTERNATIVES
AnyEvent::Run, AnyEvent::Util, Argv, Capture::Tiny, Child, Forks::Super,
IO::Pipe, IPC::Capture, IPC::Cmd, IPC::Command::Multiplex, IPC::Exe,
IPC::Open3, IPC::Open3::Simple, IPC::Run, IPC::Run3,
IPC::RunSession::Simple, IPC::ShellCmd, IPC::System::Simple,
POE::Pipe::TwoWay, Proc::Background, Proc::Fork, Proc::Spawn,
Spawn::Safe, System::Command
SUPPORT
This distribution is managed via github:
https://github.com/mlawren/sys-cmd/tree/devel
This distribution follows the semantic versioning model:
http://semver.org/
Code is tidied up on Git commit using githook-perltidy:
http://github.com/mlawren/githook-perltidy
AUTHOR
Mark Lawrence <
[email protected]>, based heavily on
Git::Repository::Command by Philippe Bruhat (BooK).
COPYRIGHT AND LICENSE
Copyright 2011-2014 Mark Lawrence <
[email protected]>
This program is free software; you can redistribute it and/or modify it
under the terms of the GNU General Public License as published by the
Free Software Foundation; either version 3 of the License, or (at your
option) any later version.