Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!mailrus!cs.utexas.edu!rutgers!orstcs!sapphire!pvo3366
From: pvo3366@sapphire.OCE.ORST.EDU (Paul O'Neill)
Newsgroups: alt.sources.d
Subject: Re: Cmail - C or perl or whatever
Message-ID: <13411@orstcs.CS.ORST.EDU>
Date: 28 Oct 89 05:45:08 GMT
References: <1125@kl-cs.UUCP> <2473@convex.UUCP> <14810@bfmny0.UU.NET>
Sender: usenet@orstcs.CS.ORST.EDU
Reply-To: pvo3366@sapphire.OCE.ORST.EDU (Paul O'Neill)
Organization: Coastal Imaging Lab, Oregon State University, Corvallis, OR
Lines: 44

In article <14810@bfmny0.UU.NET> tneff@bfmny0.UU.NET (Tom Neff) writes:
>
>And please note that the cute device
>
>	#!/usr/bin/perl [-flags]
>
>which lets some users run perl scripts directly by name as ziplessly as
>if they were standalone executables, DOES NOT WORK everywhere.  On my
>system, it would be necessary to create companion shell scripts or Korn
>shell aliases to invoke any such script.
>

Perl is so cool.  From the man page:

     -S   makes perl use the PATH environment variable to  search
          for  the  script  (unless the name of the script starts
          with a slash).  Typically this is used  to  emulate  #!
          startup  on machines that don't support #!, in the fol-
          lowing manner:

               #!/usr/bin/perl
               eval "exec /usr/bin/perl -S $0 $*"
                    if $running_under_some_shell;

          The system ignores the first line and feeds the  script
          to  /bin/sh,  which proceeds to try to execute the perl
          script as a  shell  script.   The  shell  executes  the
          second  line as a normal shell command, and thus starts
          up the perl interpreter.  On some  systems  $0  doesn't
          always  contain the full pathname, so the -S tells perl
          to search for the  script  if  necessary.   After  perl
          locates  the  script,  it  parses the lines and ignores
          them because the variable $running_under_some_shell  is
          never true.

Tom Christiansen obviously wrote the program to show off the language, not
to do the job.  Take a hint.  You're not out in the cold if your vendor
didn't supply it.  Scarf it, install it.  You and your users will thank you.


Paul O'Neill                 pvo@oce.orst.edu
Coastal Imaging Lab
OSU--Oceanography
Corvallis, OR  97331         503-754-3251