Re: $0 and path

On Friday, August 2, 2002, at 05:32 , Chip Place wrote:

> Another interesting bit of information:
>
> If I invoke the script like this
>
> $ perl myperlscript
>
> I don't get the leading ./ or path
>
> does this make any sense?
yes.

it is the same as invoking a shell script with

        sh some_shell_script

when you invoke an 'executable' from the
command line - you either

        a) provide the fully qualified path,
                as you do with

                        ./myScript

        b) hope that it is in the PATH "line"

and hence it will be found 'fully qualified'

what you might want to do is notice that the
indirections to a perl script are relatively constant:

mex.wetware.com: 70:] Iam
/home/drieux/bin/Iam is In /home/drieux/bin - but Called from 
/.amd_mnt/gax/export/src/bsd/4.6/perl-5.6.1/lib
mex.wetware.com: 71:]
gax: 63:] ../bin/Iam
.../bin/Iam is In ../bin - but Called from /export/home/drieux/perl
gax: 64:] perl ../bin/Iam
.../bin/Iam is In ../bin - but Called from /export/home/drieux/perl
gax: 65:]
gax: 67:] perl Iam
Iam is In . - but Called from /export/home/drieux/bin
gax: 68:]



all driven by the same piece of code see below.

so you will also notice that your 'presumption' that

        perl myScript

holds 'truish' - ONLY when it is invoked in the
same directory where the script is....


ciao
drieux

http://www.wetware.com/drieux/pbl/

--------------
gax: 65:] sed 's/^/### /' !$
sed 's/^/### /' ../bin/Iam
### #!/usr/bin/perl -w
### use strict;
### use File::Basename qw/dirname/;
### use Cwd;
###
### # Iam - a piece of code to help with who is where when invoked
###
### my $name = $0;
### my $dir = dirname $name;
### my $curdir= cwd;
###
### print $name . " is In $dir - but Called from $curdir \n";
###
### #
### # what if the distributed single sign on solution is
### # squirrelly so that $HOME interprets one way, but
### # $curdir follows the actual path vice logical path
### # How ever would we know if they were the same?
### #
###
### my $home_i = (stat $ENV{HOME})[1];
### my $cur_i = (stat $curdir)[1];
###
### if( $home_i == $cur_i ) {
###     my $there = ($ENV{HOME} eq $curdir ) ? $ENV{HOME} :
###                     " \n\t known as both $ENV{HOME} and $curdir";
###     print "we are home in our Home Directory - $there \n";
###
### }
### exit(0);
gax: 66:]