Shell man page on Peanut

Man page or keyword search:  
man Server   7435 pages
apropos Keyword Search (all sections)
Output format
Peanut logo
[printable version]

Shell(3)	       Perl Programmers Reference Guide		      Shell(3)

NAME
       Shell - run shell commands transparently within perl

SYNOPSIS
	  use Shell qw(cat ps cp);
	  $passwd = cat('</etc/passwd');
	  @pslines = ps('-ww'),
	  cp("/etc/passwd", "/tmp/passwd");

	  # object oriented
	  my $sh = Shell->new;
	  print $sh->ls('-l');

DESCRIPTION
       Caveats

       This package is included as a show case, illustrating a few Perl
       features.  It shouldn't be used for production programs. Although it
       does provide a simple interface for obtaining the standard output of
       arbitrary commands, there may be better ways of achieving what you
       need.

       Running shell commands while obtaining standard output can be done with
       the "qx/STRING/" operator, or by calling "open" with a filename
       expression that ends with "|", giving you the option to process one
       line at a time.	If you don't need to process standard output at all,
       you might use "system" (in preference of doing a print with the
       collected standard output).

       Since Shell.pm and all of the aforementioned techniques use your
       system's shell to call some local command, none of them is portable
       across different systems. Note, however, that there are several built
       in functions and library packages providing portable implementations of
       functions operating on files, such as: "glob", "link" and "unlink",
       "mkdir" and "rmdir", "rename", "File::Compare", "File::Copy",
       "File::Find" etc.

       Using Shell.pm while importing "foo" creates a subroutine "foo" in the
       namespace of the importing package. Calling "foo" with arguments
       "arg1", "arg2",... results in a shell command "foo arg1 arg2...", where
       the function name and the arguments are joined with a blank. (See the
       subsection on Escaping magic characters.) Since the result is
       essentially a command line to be passed to the shell, your notion of
       arguments to the Perl function is not necessarily identical to what the
       shell treats as a command line token, to be passed as an individual
       argument to the program.	 Furthermore, note that this implies that
       "foo" is callable by file name only, which frequently depends on the
       setting of the program's environment.

       Creating a Shell object gives you the opportunity to call any command
       in the usual OO notation without requiring you to announce it in the
       "use Shell" statement. Don't assume any additional semantics being
       associated with a Shell object: in no way is it similar to a shell
       process with its environment or current working directory or any other
       setting.

       Escaping Magic Characters

       It is, in general, impossible to take care of quoting the shell's magic
       characters. For some obscure reason, however, Shell.pm quotes
       apostrophes ("'") and backslashes ("\") on UNIX, and spaces and quotes
       (""") on Windows.

       Configuration

       If you set $Shell::capture_stderr to 1, the module will attempt to
       capture the standard error output of the process as well. This is done
       by adding "2>&1" to the command line, so don't try this on a system not
       supporting this redirection.

       Setting $Shell::capture_stderr to -1 will send standard error to the
       bit bucket (i.e., the equivalent of adding "2>/dev/null" to the command
       line).  The same caveat regarding redirection applies.

       If you set $Shell::raw to true no quoting whatsoever is done.

BUGS
       Quoting should be off by default.

       It isn't possible to call shell built in commands, but it can be done
       by using a workaround, e.g. shell( '-c', 'set' ).

       Capturing standard error does not work on some systems (e.g. VMS).

AUTHOR
	 Date: Thu, 22 Sep 94 16:18:16 -0700
	 Message-Id: <9409222318.AA17072@scalpel.netlabs.com>
	 To: perl5-porters@isu.edu
	 From: Larry Wall <lwall@scalpel.netlabs.com>
	 Subject: a new module I just wrote

       Here's one that'll whack your mind a little out.

	   #!/usr/bin/perl

	   use Shell;

	   $foo = echo("howdy", "<funny>", "world");
	   print $foo;

	   $passwd = cat("</etc/passwd");
	   print $passwd;

	   sub ps;
	   print ps -ww;

	   cp("/etc/passwd", "/etc/passwd.orig");

       That's maybe too gonzo.	It actually exports an AUTOLOAD to the current
       package (and uncovered a bug in Beta 3, by the way).  Maybe the usual
       usage should be

	   use Shell qw(echo cat ps cp);

       Larry Wall

       Changes by Jenda@Krynicky.cz and Dave Cottle
       <d.cottle@csc.canterbury.ac.nz>.

       Changes for OO syntax and bug fixes by Casey West <casey@geeknest.com>.

       $Shell::raw and pod rewrite by Wolfgang Laun.

       Rewritten to use closures rather than "eval "string"" by Adriano
       Ferreira.

perl v5.10.0			  2007-12-18			      Shell(3)
[top]

List of man pages available for Peanut

Copyright (c) for man pages and the logo by the respective OS vendor.

For those who want to learn more, the polarhome community provides shell access and support.

[legal] [privacy] [GNU] [policy] [cookies] [netiquette] [sponsors] [FAQ]
Tweet
Polarhome, production since 1999.
Member of Polarhome portal.
Based on Fawad Halim's script.
....................................................................
Vote for polarhome
Free Shell Accounts :: the biggest list on the net