«

Hi,

I want to write a program that does check the appropriate system path
for perl in FreeBSD and Linux.

The path where I have it in FreeBSD is
#! /usr/local/bin/perl

and the path where it is in Linux is
#! /usr/bin/perl

I wanted the program to check for the uname of the system and choose
the appropriate path. Can anyone tell me how can I have my program
check this.

This is how I wrote the program but it doesnt work.

#! /usr/local/bin/perl

use strict;
use warnings;

if (system("uname") eq "Linux") {
#! /usr/bin/perl
}

< rest of the code >

Thanks,
doni

On Feb 27, 2:49 pm, "doni" <doni.se...@gmail.com> wrote:
> Hi,
>
> I want to write a program that does check the appropriate system path
> for perl in FreeBSD and Linux.
>
> The path where I have it in FreeBSD is
> #! /usr/local/bin/perl
>
> and the path where it is in Linux is
> #! /usr/bin/perl
>
> I wanted the program to check for the uname of the system and choose
> the appropriate path. Can anyone tell me how can I have my program
> check this.
>
> This is how I wrote the program but it doesnt work.
>
> #! /usr/local/bin/perl
>
> use strict;
> use warnings;
>
> if (system("uname") eq "Linux") {

What do you think that does?

Please read the documentation for the function you're using

perldoc -f system
perldoc -q system


> #! /usr/bin/perl

That's a comment, and nothing more. The #! syntax means nothing
unless it's the first two characters of the file.

You probably meant to do an exec()

perldoc -f exec

And to avoid an infinite loop, you'll need to make sure you're not
already executing the version you meant to. I think you'll need both
the $0 and $^X variables. You can read about them in:
perldoc perlvar
In fact, you could probably get rid of the call to uname entirely, by
using the $^0 variable, also documented in that perldoc.

Hope that helps,
Paul Lalli

doni wrote:
> Hi,
>
> I want to write a program that does check the appropriate system path
> for perl in FreeBSD and Linux.
>
> The path where I have it in FreeBSD is
> #! /usr/local/bin/perl
>
> and the path where it is in Linux is
> #! /usr/bin/perl
>
> I wanted the program to check for the uname of the system and choose
> the appropriate path. Can anyone tell me how can I have my program
> check this.


Easier to use a symlink or on your Freebsd box (it's probably on your
Linux box also), run 'use.perl port', then /usr/bin/perl will work
on both.

Quoth "doni" <>:
> Hi,
>
> I want to write a program that does check the appropriate system path
> for perl in FreeBSD and Linux.
>
> The path where I have it in FreeBSD is
> #! /usr/local/bin/perl
>
> and the path where it is in Linux is
> #! /usr/bin/perl
>
> I wanted the program to check for the uname of the system and choose
> the appropriate path. Can anyone tell me how can I have my program
> check this.

This is not a Perl question. The path on the #! line is not used by
perl, but by your operating system. In general, there is no way to put
any logic into that line, though

#!/usr/bin/env perl

may do what you want. Note that it will use the perl in your current
PATH, which may be a security risk. As others have said, you are much
better off arranging for perl to be available as /usr/bin/perl, or
writing some sort of installation script that changes the #! line.

Ben

--
For far more marvellous is the truth than any artists of the past imagined!
Why do the poets of the present not speak of it? What men are poets who can
speak of Jupiter if he were like a man, but if he is an immense spinning
sphere of methane and ammonia must be silent? [Feynmann]

On Feb 27, 2:09 pm, Ben Morrow <b...@morrow.me.uk> wrote:
> This is not a Perl question. The path on the #! line is not used by
> perl, but by your operating system. In general, there is no way to put
> any logic into that line, though
>
> #!/usr/bin/env perl
>
> may do what you want. Note that it will use the perl in your current
> PATH, which may be a security risk. As others have said, you are much
> better off arranging for perl to be available as /usr/bin/perl, or
> writing some sort of installation script that changes the #! line.
>
> Ben

Thanks for your input. I will have an installation script to change
the #! line.

Thanks,
doni

On 2007-02-27 22:09, Ben Morrow <> wrote:
> Quoth "doni" <>:
[changing the shebang line depending on uname]
> As others have said, you are much better off arranging for perl to be
> available as /usr/bin/perl, or writing some sort of installation
> script that changes the #! line.

If you use ExtUtils::MakeMaker or Module::Build, this is done
automatically at install time.

hp


--
_ | Peter J. Holzer | Es ist ganz einfach ihn zu verstehen, wenn
|_|_) | Sysadmin WSR | man nur alle wichtigen Worte im Satz durch
| | | | andere ersetzt.
__/ | http://www.hjp.at/ | -- Nils Ketelsen in danr

doni schreef:

> I want to write a program that does check the appropriate system path
> for perl in FreeBSD and Linux.

which -a perl

--
Affijn, Ruud

"Gewoon is een tijger."