CODEWITHSUNDEEP
perl
zdd
zdd

Reputation: 8727

How to set the cross platform interpreter path?

I would like my scripts works on Windows and UNIX system, so I want some code as blew(just a sample, not work)

if $^O eq 'MSWin32' {
#!/c:/perl/bin/perl.exe
}
else { / non-windows system
#!/usr/local/bin/perl
}

is there any way to do this in perl? it seems the #! line must be the first line of a perl script, so this is impossible?

Upvotes: 1

Views: 277

Answers (3)

ikegami
ikegami

Reputation: 385897

#! must be the first two characters of the file, because that's where the kernel looks for them when it tries to launch your file. They're part of a directive for the OS (called the shebang line), and the OS knows nothing about Perl.

If you use a standard Perl installer (such as ExtUtils::MakeMaker) to installer your script, just use #!perl and the installer will adjust any existing #! line for your system.

Upvotes: 4

amon
amon

Reputation: 57640

The shebang (#!/path/to/interpreter) is only used on unix-like systems. And it has to be the first line. On Windows systems, the shebang is not used, instead file ending associations may be used: you can associate the .pl file ending with the perl interpreter.

Command line switches in the shebang will be interpreted by the perl interpreter, regardless of platform.

A safe way to launch perl scripts on all platforms is to actually use the perl command. It will be available in case of an successfull Perl installation. E.g. perl myscript.pl instead of ./myscript.pl. The second options requires that the file is set as "executable" on *nix systems.

Upvotes: 4

Christian Stieber
Christian Stieber

Reputation: 12496

It's not possible. The "#!" is looked at by the exec*() family of Unix functions, to determine how to run the file. So you can't do any scripting there.

It's not all that useful anyway, since the Windows command prompt (or CreateProc() function, but I'm not sure whether that can be used to launch a batch file) doesn't look for the #!.

Upvotes: 2

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