-s switch with -e

jcc has asked for the wisdom of the Perl Monks concerning the following question:

Greetings

Can someone tell me why this doesn't DWIM?

$ perl -se 'print $foo' -foo=bar  
Unrecognized switch: -foo=bar  (-h will show valid options).
[download]

I've tried other configurations:

 
perl -e -s 'print $foo' -foo=bar
[download]

doesn't do anything

$ perl -es 'print $foo' -foo=bar  
Substitution pattern not terminated at -e line 1.

$ perl -e -s -foo=bar 'print $foo'
Unrecognized switch: -foo=bar  (-h will show valid options).
[download]

I know it's not a quoting issue:

$ perl -e 'print $='     
60
[download]

Any thoughts?

Comment on -s switch with -e Select or Download Code

Replies are listed 'Best First'.
Re: -s switch with -e by lidden (Curate) on Apr 17, 2006 at 20:43 UTC
`perl -se 'print $foo' -- -foo=bar` Works, without '--' the switch is sent to perl instead of your script.	[reply] [d/l]
Re: -s switch with -e by ikegami (Patriarch) on Apr 17, 2006 at 22:27 UTC
Since noone explained the solution, I will: Perl will absorb everything that starts with a dash until it meets something that doesn't start with dash or until it meets "--". The code attached to `-e` is considered part of `-e`, so it doesn't interrupt the scanning for options. `-s` scans whatever is left would otherwise go to @ARGV. `Interpreted as perl options vv vvvvvvvvvv vvvvvv perl -s -e "print" -foo=a a b ^ ^ @ARGV, which -s scans Interpreted as perl options vv perl -s script.pl -foo=a a b ^^^^^^ ^ ^ @ARGV, which -s scans Interpreted as perl options vv vvvvvvvvvv vv perl -s -e "print" -- -foo=a a b ^^^^^^ ^ ^ @ARGV, which -s scans` [download]	[reply] [d/l] [select]
Re: -s switch with -e by Tanktalus (Canon) on Apr 17, 2006 at 20:44 UTC
I can suggest trying: `$ perl -se 'print $foo,$/' -- -foo=bar bar` [download] I kind of extrapolated this from the perlrun docs, and, although I kinda can see it (perl trying to figure out where its arguements stop and yours start), it definitely doesn't do what I expect based on it being able to figure this out just fine when not using the -s flag.	[reply] [d/l]
Re: -s switch with -e by tempest (Sexton) on Apr 17, 2006 at 20:48 UTC
this is meant for program files. why not just `perl -e '$foo="bar";print $foo'` [download] or just save the file as `#!/usr/bin/perl -s print $foo; #then in the command line #file.pl -foo=bar` [download]	[reply] [d/l] [select]
Re^2: -s switch with -e by jcc (Sexton) on Apr 18, 2006 at 01:39 UTC
sorry... the impetus behind the question was this node. I was trying to wrap my mind around a solution I thought should be pretty slick but that I couldn't make work in practice. Thanks to everyone who helped me get my mind around this. Apologies to graff who's update I didn't consult in time.	[reply]