perlsh (1) Linux Manual Page

perlsh – one-line perl evaluator with line editing function and          variable name completion function

Synopsis

 perlsh

Description

This program reads input a line, and evaluates it by perl interpreter, and prints the result. If the result is a list value then each value of the list is printed line by line. This program can be used as a very strong calculator which has whole perl functions.

This is a sample program Term::ReadLine::Gnu module. When you input a line, the line editing function of GNU Readline Library is available. Perl symbol name completion function is also available.

Before invoking, this program reads ~/.perlshrc and evaluates the content of the file.

When this program is terminated, the content of the history buffer is saved in a file ~/.perlsh_history, and it is read at next invoking.

Variables

You can customize the behavior of "perlsh" by setting following variables in ~/.perlshrc;

$PerlSh::PS1

The primary prompt string. The following backslash-escaped special characters can be used.

 \h: host name

 \u: user name

 \w: package name

 \!: history number

The default value is `"\w[\!]$ "‘.

$PerlSh::PS2

The secondary prompt string. The default value is `"> "‘.

$PerlSh::HISTFILE

The name of the file to which the command history is saved. The default value is "~/.perlsh_history".

$PerlSh::HISTSIZE

If not "undef", this is the maximum number of commands to remember in the history. The default value is 256.

$PerlSh::STRICT

If true, restrict unsafe constructs. See "use strict" in perl man page. The default value is 0;

Files

~/.perlshrc

This file is eval-ed at initialization. If a subroutine "afterinit" is defined in this file, it will be eval-ed after initialization. Here is a sample.

 # -*- mode: perl -*-

 # decimal to hexa

 sub h { map { sprintf("0x%x", $_ ) } @_;}

 sub tk {

 $t->tkRunning(1);

 use Tk;

 $mw = MainWindow->new();

 }

 # for debugging Term::ReadLine::Gnu

 sub afterinit {

 *t = \$PerlSh::term;

 *a = \$PerlSh::attribs;

 }

~/.perlsh_history

~/.inputrc

A initialization file for the GNU Readline Library. Refer its manual for details.

See Also

Term::ReadLine::Gnu <http://search.cpan.org/dist/Term-ReadLine-Gnu/>

GNU Readline Library <http://cnswww.cns.cwru.edu/php/chet/readline/rltop.html>

Author

Hiroo Hayashi <hiroo.hayashi [at] computer.org>