NAME

       Rex::Commands::Run - Execute a remote command

DESCRIPTION

       With this module you can run a command.

SYNOPSIS

        my $output = run 'ls -l';
        sudo 'id';

CONFIGURATION AND ENVIRONMENT

       Please note that Rex may set the "PATH" environment variable when executing commands on
       the user's behalf to a different value compared to executing the same commands manually.
       The following are available to control the related behavior:

       path command
       set_path configuration option
       no_path_cleanup feature flag
       source_profile feature flag
       source_global_profile feature flag

EXPORTED FUNCTIONS

   run($command [, $callback], %options)
       This function will execute the given $command and returns the output. In scalar context it
       returns the raw output as is, and in list context it returns the list of output lines. The
       exit value of the command is stored in the $? variable.

        run 'uptime';
        my $output       = run 'uptime';
        my @output_lines = run 'uptime';

       Please note when the "tty" feature flag is enabled the combined output containing both
       "STDOUT" and "STDERR" is returned via "STDOUT". When using the "no_tty" feature flag, or
       the 1.0 feature bundle (or newer), then "run()" returns only the "STDOUT" output of the
       command.

       To access separate "STDOUT" and "STDERR" output, use a callback subroutine, for example:

        run 'uptime', sub {
          my ( $stdout, $stderr ) = @_;
          my $server = Rex::get_current_connection()->{server};
          say "[$server] $stdout\n";
        };

       It also takes further options in a form of a hash. Supported options are:

       cwd => $path
           Sets the working directory of the executed command to $path.

       only_if => $condition_command
           Executes the command only if $condition_command returns success.

       unless => $condition_command
           Executes the command if $condition_command returns failure.

       only_notified => TRUE
           Queues the command to be executed later upon notification.

       env => { var1 => $value1, ..., varN => $valueN }
           Sets environment variables for the given command.

       timeout => value
           Sets the timeout for the command to be run.

       auto_die => TRUE
           Die if the command returns with an exit code indicating failure. It can be set
           globally via the exec_autodie feature flag.

       command => $command_to_run
           If present, Rex will execute $command_to_run, and treat the first argument as an
           identifier for the given "run()" block (e.g. to be triggered with notify).

       creates => $file_to_create
           Tries to create $file_to_create upon execution, and skips execution if the file
           already exists.

       continuous_read => $callback
           Calls $callback subroutine reference for each line of the command's output, passing
           the line as an argument.

       end_if_matched => qr{$pattern}
           End execution early as soon as $pattern is detected in the command's output.

       Examples:

       If you only want to run a command if another command succeeds or fails, use the "only_if"
       or "unless" options.

        run 'some-command',
          only_if => 'pgrep httpd'; # only run if httpd is running

        run 'some-other-command',
          unless => 'pgrep httpd'; # only run if httpd is _not_ running

       If you want to set custom environment variables you can do it like this:

        run 'my_command',
          env => {
            env_var_1 => 'the value for 1',
            env_var_2 => 'the value for 2',
          };

       If you want to end the command upon receiving a certain output:

        run 'my_command',
          end_if_matched => qr{$pattern};

   run($command, $arguments, %options)
       This form will execute $command with the given $arguments pass as an array reference.  All
       arguments will be quoted by Rex with "Net::OpenSSH::ShellQuoter->quoter()" according to
       the managed host's shell.

        run 'ls', [ '-l', '-t', '-r', '-a' ];
        run 'ls', [ '/tmp', '-l' ], auto_die => TRUE;

   run($command_description, command => $command, %options)
       If you only want to run a command in certain cases, you can queue the command and notify
       it to trigger its execution.

        run 'extract-something',
          command       => 'tar -C /foo -xzf /tmp/foo.tgz',
          only_notified => TRUE;

        # some code ...

        notify 'run', 'extract-something'; # now the command gets executed

   can_run($command)
       This function checks if a command is available in the path. It accepts a list of commands,
       and returns the full path to the first command found.

        task 'uptime', sub {
          if ( my $cmd = can_run( 'uptime', 'downtime' ) ) {
            say run $cmd;
          }
        };

   sudo
       Run a single command, a code block, or all commands with "sudo". You need perl to be
       available on the remote systems to use "sudo".

       Depending on your remote sudo configuration, you may need to define a sudo password with
       sudo_password first:

        sudo_password 'my_sudo_password'; # hardcoding

       Or alternatively, since Rexfile is plain perl, you can read the password from terminal at
       the start:

        use Term::ReadKey;

        print 'I need sudo password: ';
        ReadMode('noecho');
        sudo_password ReadLine(0);
        ReadMode('restore');

       Similarly, it is also possible to read it from a secret file, database, etc.

       You can turn sudo on globally with:

        sudo TRUE; # run _everything_ with sudo

       To run only a specific command with sudo, use :

        say sudo 'id';                # passing a remote command directly
        say sudo { command => 'id' }; # passing anonymous hashref

        say sudo { command => 'id', user => 'different' }; # run a single command with sudo as different user

       To run multiple commands with "sudo", either use an anonymous code reference directly:

        sudo sub {
            service 'nginx' => 'restart';
            say run 'id';
        };

       or pass it via "command" (optionally along a different user):

        sudo {
            command => sub {
                say run 'id';
                say run 'pwd', cwd => '/home/different';
            },
            user => 'different',
        };

       Note that some users receive the error "sudo: sorry, you must have a tty to run sudo". In
       this case you have to disable "requiretty" for this user.  You can do this in your sudoers
       file with the following code:

          Defaults:$username !requiretty