Re: OS independent perl script

[DrHyde]

The hardest bit IMO isn't writing the perl code, it's making it executable on all the bizarro platforms that perl runs on. That is, to get the #! line right on Unix-a-likes, but make it a valid .BAT file on Windows, and whatever is needed on VMS.

Thankfully, there's a tool to do that.

ExtUtils::MakeMaker and, presumably, Module::Build, have the smarts to edit your scripts appropriately at install time so you don't have to worry about it. If for some reason you can't use either of those tools, then the maximally portable preamble for Unix-a-likes is:

#!/bin/sh
exec perl -x $0 "$@"
#!perl

# your perl code goes here

but I have no idea what to do, or even if you can, make that also portable to other platforms.

[Corion]

For Windows, there is a really simple .cmd file that I use to launch a plain Perl script with the same name:

@echo off
perl -w %~dpn0.pl

For a file test.cmd, this will launch perl -w test.pl in the same directory as test.cmd.

[DrHyde]

Is %~dpn0 some bizarro shell magic then?

[Corion]

Yep.

%0 corresponds to $0, and the magic letters behind the tilde are explained (for example) here.

[Anonymous Monk]

See also  help for and Re: Command line arguments not passed in Win7 ( regqueryperl.bat ), Question on Strawberry's Portable .bat file

@setlocal
@set thisdir=%~dp0
@set thisfile=%~f0
@set thisfilebasename=%~n0
@set thisfilename=%~nx0
@set thisfilecorion=%~dpn0.pl
@set thisfilepl=%thisdir%%thisfilebasename%.pl
@echo          thisdir=%thisdir%
@echo         thisfile=%thisfile%
@echo thisfilebasename=%thisfilebasename%
@echo     thisfilename=%thisfilename%
@echo   thisfilecorion=%thisfilecorion%
@echo       thisfilepl=%thisfilepl%
@echo;
@endlocal

         thisdir=D:\
        thisfile=D:\this2.bat
thisfilebasename=this2
    thisfilename=this2.bat
  thisfilecorion=D:\this2.pl
      thisfilepl=D:\this2.pl

---

And the advanced broken version (for stupid paths )
^ is trickier than the others ... above escaping useful for example if you're  echo %stuff% >> otherfile.bat
yes, cmd.exe is a mess

@setlocal
@set "thisdir=%~dp0"
@set "thisfile=%~f0"
@set "thisfilebasename=%~n0"
@set "thisfilename=%~nx0"
@set "thisfilecorion=%~dpn0.pl"
@set "thisfilepl=%thisdir%%thisfilebasename%.pl"
@echo          thisdir="%thisdir%         
@echo         thisfile="%thisfile%        
@echo thisfilebasename="%thisfilebasename%
@echo     thisfilename="%thisfilename%    
@echo   thisfilecorion="%thisfilecorion%  
@echo       thisfilepl="%thisfilepl%      
@echo;
@set "thisfile=%~f0"
echo %thisfile%
@set "thisfile=%thisfile:^=\^%"
@set "thisfile=%thisfile:>=^>%"
@set "thisfile=%thisfile:<=^<%"
@set "thisfile=%thisfile:&=^&%"
@set "thisfile=%thisfile:|=^|%"
@set "thisfile=%thisfile:)=^)%"
@set "thisfile=%thisfile:(=^(%"
@set "thisfile=%thisfile:[=^[%"
@set "thisfile=%thisfile:]=^]%"
@set "thisfile=%thisfile:"=\"%"
@echo escaped-thisfile "%thisfile%"
@echo;
@endlocal

$  "D:\pa^th\this2.bat"
         thisdir=D:\path\
        thisfile=D:\path\this2.bat
thisfilebasename=this2
    thisfilename=this2.bat
  thisfilecorion=D:\path\this2.pl
      thisfilepl=D:\path\this2.pl