NAME

    Shell::Config::Generate - Portably generate config for any shell

VERSION

    version 0.34

SYNOPSIS

    With this start up:

     use Shell::Guess;
     use Shell::Config::Generate;
     
     my $config = Shell::Config::Generate->new;
     $config->comment( 'this is my config file' );
     $config->set( FOO => 'bar' );
     $config->set_path(
       PERL5LIB => '/foo/bar/lib/perl5',
                   '/foo/bar/lib/perl5/perl5/site',
     );
     $config->append_path(
       PATH => '/foo/bar/bin',
               '/bar/foo/bin',
     );

    This:

     $config->generate_file(Shell::Guess->bourne_shell, 'config.sh');

    will generate a config.sh file with this:

     # this is my config file
     FOO='bar';
     export FOO;
     PERL5LIB='/foo/bar/lib/perl5:/foo/bar/lib/perl5/perl5/site';
     export PERL5LIB;
     if [ -n "$PATH" ] ; then
       PATH=$PATH:'/foo/bar/bin:/bar/foo/bin';
       export PATH
     else
       PATH='/foo/bar/bin:/bar/foo/bin';
       export PATH;
     fi;

    and this:

     $config->generate_file(Shell::Guess->c_shell, 'config.csh');

    will generate a config.csh with this:

     # this is my config file
     setenv FOO 'bar';
     setenv PERL5LIB '/foo/bar/lib/perl5:/foo/bar/lib/perl5/perl5/site';
     test "$?PATH" = 0 && setenv PATH '/foo/bar/bin:/bar/foo/bin' || setenv PATH "$PATH":'/foo/bar/bin:/bar/foo/bin';

    and this:

     $config->generate_file(Shell::Guess->cmd_shell, 'config.cmd');

    will generate a config.cmd (Windows cmd.exe script) with this:

     rem this is my config file
     set FOO=bar
     set PERL5LIB=/foo/bar/lib/perl5;/foo/bar/lib/perl5/perl5/site
     if defined PATH (set PATH=%PATH%;/foo/bar/bin;/bar/foo/bin) else (set PATH=/foo/bar/bin;/bar/foo/bin)

DESCRIPTION

    This module provides an interface for specifying shell configurations
    for different shell environments without having to worry about the
    arcane differences between shells such as csh, sh, cmd.exe and
    command.com.

    It does not modify the current environment, but it can be used to
    create shell configurations which do modify the environment.

    This module uses Shell::Guess to represent the different types of
    shells that are supported. In this way you can statically specify just
    one or more shells:

     #!/usr/bin/perl
     use Shell::Guess;
     use Shell::Config::Generate;
     my $config = Shell::Config::Generate->new;
     # ... config config ...
     $config->generate_file(Shell::Guess->bourne_shell,  'foo.sh' );
     $config->generate_file(Shell::Guess->c_shell,       'foo.csh');
     $config->generate_file(Shell::Guess->cmd_shell,     'foo.cmd');
     $config->generate_file(Shell::Guess->command_shell, 'foo.bat');

    This will create foo.sh and foo.csh versions of the configurations,
    which can be sourced like so:

     #!/bin/sh
     . ./foo.sh

    or

     #!/bin/csh
     source foo.csh

    It also creates .cmd and .bat files with the same configuration which
    can be used in Windows. The configuration can be imported back into
    your shell by simply executing these files:

     C:\> foo.cmd

    or

     C:\> foo.bat

    Alternatively you can use the shell that called your Perl script using
    Shell::Guess's running_shell method, and write the output to standard
    out.

     #!/usr/bin/perl
     use Shell::Guess;
     use Shell::Config::Generate;
     my $config = Shell::Config::Generate->new;
     # ... config config ...
     print $config->generate(Shell::Guess->running_shell);

    If you use this pattern, you can eval the output of your script using
    your shell's back ticks to import the configuration into the shell.

     #!/bin/sh
     eval `script.pl`

    or

     #!/bin/csh
     eval `script.pl`

CONSTRUCTOR

 new

     my $config = Shell::Config::Generate->new;

    creates an instance of She::Config::Generate.

METHODS

    There are two types of instance methods for this class:

      * modifiers

      adjust the configuration in an internal portable format

      * generators

      generate shell configuration in a specific format given the internal
      portable format stored inside the instance.

    The idea is that you can create multiple modifications to the
    environment without worrying about specific shells, then when you are
    done you can create shell specific versions of those modifications
    using the generators.

    This may be useful for system administrators that must support users
    that use different shells, with a single configuration generation
    script written in Perl.

 set

     $config->set( $name => $value );

    Set an environment variable.

 set_path

     $config->set_path( $name => @values );

    Sets an environment variable which is stored in standard 'path' format
    (Like PATH or PERL5LIB). In UNIX land this is a colon separated list
    stored as a string. In Windows this is a semicolon separated list
    stored as a string. You can do the same thing using the set method, but
    if you do so you have to determine the correct separator.

    This will replace the existing path value if it already exists.

 append_path

     $config->append_path( $name => @values );

    Appends to an environment variable which is stored in standard 'path'
    format. This will create a new environment variable if it doesn't
    already exist, or add to an existing value.

 prepend_path

     $config->prepend_path( $name => @values );

    Prepend to an environment variable which is stored in standard 'path'
    format. This will create a new environment variable if it doesn't
    already exist, or add to an existing value.

 comment

     $config->comment( $comment );

    This will generate a comment in the appropriate format.

    note that including comments in your configuration may mean it will not
    work with the eval backticks method for importing configurations into
    your shell.

 shebang

     $config->shebang;
     $config->shebang($location);

    This will generate a shebang at the beginning of the configuration,
    making it appropriate for use as a script. For non UNIX shells this
    will be ignored. If specified, $location will be used as the
    interpreter location. If it is not specified, then the default location
    for the shell will be used.

    note that the shebang in your configuration may mean it will not work
    with the eval backticks method for importing configurations into your
    shell.

 echo_off

     $config->echo_off;

    For DOS/Windows configurations (command.com or cmd.exe), issue this as
    the first line of the config:

     @echo off

 echo_on

     $config->echo_on;

    Turn off the echo off (that is do not put anything at the beginning of
    the config) for DOS/Windows configurations (command.com or cmd.exe).

 set_alias

     $config->set_alias( $alias => $command )

    Sets the given alias to the given command.

    Caveat: some older shells do not support aliases, such as the original
    bourne shell. This module will generate aliases for those shells
    anyway, since /bin/sh may actually be a more modern shell that DOES
    support aliases, so do not use this method unless you can be reasonable
    sure that the shell you are generating supports aliases. On Windows,
    for PowerShell, a simple function is used instead of an alias so that
    arguments may be specified.

 set_path_sep

     $config->set_path_sep( $sep );

    Use $sep as the path separator instead of the shell default path
    separator (generally : for Unix shells and ; for Windows shells).

    Not all characters are supported, it is usually best to stick with the
    shell default or to use : or ;.

 generate

     my $command_text = $config->generate;
     my $command_text = $config->generate( $shell );

    Generate shell configuration code for the given shell. $shell is an
    instance of Shell::Guess. If $shell is not provided, then this method
    will use Shell::Guess to guess the shell that called your perl script.

    You can also pass in the shell name as a string for $shell. This should
    correspond to the appropriate name_shell from Shell::Guess. So for csh
    you would pass in "c" and for tcsh you would pass in "tc", etc.

 generate_file

     $config->generate_file( $shell, $filename );

    Generate shell configuration code for the given shell and write it to
    the given file. $shell is an instance of Shell::Guess. If there is an
    IO error it will throw an exception.

FUNCTIONS

 win32_space_be_gone

     my @new_path_list = win32_space_be_gone( @orig_path_list );

    On MSWin32 and cygwin:

    Given a list of directory paths (or filenames), this will return an
    equivalent list of paths pointing to the same file system objects
    without spaces. To do this Win32::GetShortPathName() is used on to find
    alternative path names without spaces.

    NOTE that this breaks when Windows is told not to create short (8+3)
    filenames; see http://www.perlmonks.org/?node_id=333930 for a
    discussion of this behaviour.

    In addition, on just Cygwin:

    The input paths are first converted from POSIX to Windows paths using
    Cygwin::posix_to_win_path, and then converted back to POSIX paths using
    Cygwin::win_to_posix_path.

    Elsewhere:

    Returns the same list passed into it

 cmd_escape_path

     my @new_path_list = cmd_escape_path( @orig_path_list )

    Given a list of directory paths (or filenames), this will return an
    equivalent list of paths escaped for cmd.exe and command.com.

 powershell_escape_path

     my @new_path_list = powershell_escape_path( @orig_path_list )

    Given a list of directory paths (or filenames), this will return an
    equivalent list of paths escaped for PowerShell.

CAVEATS

    The test suite tests this module's output against the actual shells
    that should understand them, if they can be found in the path. You can
    generate configurations for shells which are not available (for example
    cmd.exe configurations from UNIX or bourne configurations under
    windows), but the test suite only tests them if they are found during
    the build of this module.

    The implementation for csh depends on the external command test. As far
    as I can tell test should be available on all modern flavors of UNIX
    which are using csh. If anyone can figure out how to prepend or append
    to path type environment variable without an external command in csh,
    then a patch would be appreciated.

    The incantation for prepending and appending elements to a path on csh
    probably deserve a comment here. It looks like this:

     test "$?PATH" = 0 && setenv PATH '/foo/bar/bin:/bar/foo/bin' || setenv PATH "$PATH":'/foo/bar/bin:/bar/foo/bin';

      * one line

      The command is all on one line, and doesn't use if, which is probably
      more clear and ideomatic. This for example, might make more sense:

       if ( $?PATH == 0 ) then
         setenv PATH '/foo/bar/bin:/bar/foo/bin'
       else
         setenv PATH "$PATH":'/foo/bar/bin:/bar/foo/bin'
       endif

      However, this only works if the code interpreted using the csh source
      command or is included in a csh script inline. If you try to invoke
      this code using csh eval then it will helpfully convert it to one
      line and if does not work under csh in one line.

    There are probably more clever or prettier ways to append/prepend path
    environment variables as I am not a shell programmer. Patches welcome.

    Only UNIX (bourne, bash, csh, ksh, fish and their derivatives) and
    Windows (command.com, cmd.exe and PowerShell) are supported so far.

    Fish shell support should be considered a tech preview. The Fish shell
    itself is somewhat in flux, and thus some tests are skipped for the
    Fish shell since behavior is different for different versions. In
    particular, new lines in environment variables may not work on newer
    versions.

    Patches welcome for your favorite shell / operating system.

AUTHOR

    Author: Graham Ollis <plicease@cpan.org>

    Contributors:

    Brad Macpherson (BRAD, brad-mac)

    mohawk

COPYRIGHT AND LICENSE

    This software is copyright (c) 2017 by Graham Ollis.

    This is free software; you can redistribute it and/or modify it under
    the same terms as the Perl 5 programming language system itself.

