A Perl script's interaction with Ruby's system call

ruby-talk
1

I’m trying to invoke a perl script (epstopdf) with Ruby’s system command
on a x86 box running GNU/Linux (RH7.2) which begins with the following trickery:

eval ‘(exit $?0)’ && eval ‘exec perl -S $0 ${1+"$@"}’ && eval ‘exec perl -S $0 $argv:q’ if 0;
use strict;

Change by Thomas Esser, Sept. 1998: The above lines allows us to find

perl along $PATH rather than guessing a fixed location. The above

construction should work with most shells.

but I am getting the old “Command not found” error since the trickery fails
to find perl.

If I instead tailor the system call to my particular installation of the epstopdf script
with ‘perl /usr/bin/epstopdf’, the system call works as expected.

Is there a way to use Ruby’s system command with the more general ‘epstopdf’ system
call and the above style of perl trickery?

Thanks in advance,

···

–
Bil Kleb
NASA Langley Research Center
Hampton, Virginia, USA

2

— epstopdf (make sure that it’s on the PATH, and that it’s chmod +x)
#! /usr/bin/env perl
… other stuff

— your ruby program
system(“epstopdf …”)

···

On Friday 21 June 2002 12:44 pm, Bil Kleb wrote:

I’m trying to invoke a perl script (epstopdf) with Ruby’s system
command on a x86 box running GNU/Linux (RH7.2) which begins with
the following trickery:

eval ‘(exit $?0)’ && eval ‘exec perl -S $0 ${1+“$@”}’ && eval
‘exec perl -S $0 $argv:q’ if 0; use strict;

Is there a way to use Ruby’s system command with the more general
‘epstopdf’ system call and the above style of perl trickery?

–
Ned Konz
http://bike-nomad.com
GPG key ID: BEEA7EFE

3

Hi,

···

At Sat, 22 Jun 2002 09:25:18 +0900, Ned Konz wrote:

On Friday 21 June 2002 12:44 pm, Bil Kleb wrote:

I’m trying to invoke a perl script (epstopdf) with Ruby’s system
command on a x86 box running GNU/Linux (RH7.2) which begins with
the following trickery:

eval ‘(exit $?0)’ && eval ‘exec perl -S $0 ${1+“$@”}’ && eval
‘exec perl -S $0 $argv:q’ if 0; use strict;

Is there a way to use Ruby’s system command with the more general
‘epstopdf’ system call and the above style of perl trickery?

— epstopdf (make sure that it’s on the PATH, and that it’s chmod +x)
#! /usr/bin/env perl
… other stuff

Now ruby can’t run a script without #! line (ruby-bugs:PR#315).

–
Nobu Nakada

4

Ned Konz wrote:

#! /usr/bin/env perl
… other stuff

This is third party stuff installed on all sorts of machines that
I have no control over so this is not an option. :frowning:

···

nobu.nokada@softhome.net wrote:

Now ruby can’t run a script without #! line (ruby-bugs:PR#315).

OK, I guess I’ll just use which epstopdf to find the location of
epstopdf for now, and suggest that the author use

#!/usr/bin/env perl

Thanks,

Bil