Shell usable?

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

Dear monks,

do I use Shell.pm properly?

#!/usr/bin/perl -w
use strict;
use Shell qw( ls touch );

my $sh = Shell->new;
$sh->touch( "dummy" );
$sh->ls( "dummy" );
$sh->ls( "dummy" );
[download]

This results in error messages

sh: -c: line 1: syntax error near unexpected token `Shell=SCALAR(0'
sh: -c: line 1: `ls Shell=SCALAR(0x8109c4c) dummy'
[download]

I normally use system() but those errors in a core module are unexpected to me. The errors (?) pop up as soon as a Shell command is used a second time.

Thanks for your time,
Axel

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Re: Shell usable? by broquaint (Abbot) on Jul 02, 2002 at 15:46 UTC
After a brief review of `Shell.pm` it looks like a bug where the callee reference isn't being `shift`ed off `@_`. The reason this works the first time around is that the method is `AUTOLOAD`ed and the callee has already been dealt with. If this hasn't already been patched by 5.8.0 I'll submit one to p5p later on today. In the mean time just use the procedural interface as it doesn't seem to have the same problem. HTH `_________ broquaint`	[reply]
Re: Shell usable? by amphiplex (Monk) on Jul 02, 2002 at 15:38 UTC
Hi ! I believe you are doing a bit too much here, this should work: `#!/usr/bin/perl -w use strict; use Shell qw( ls touch ); touch( "dummy" ); ls( "dummy" );` [download] ---- kurt	[reply] [d/l]
Re: Re: Shell usable? by axelrose (Scribe) on Jul 02, 2002 at 15:57 UTC
sorry, I misunderstood you saying "doing too much" I tried again not using OO style `#!/usr/bin/perl -w use strict; use Shell qw( ls touch ); touch( "dummy" ) or die "touch: $!"; ls( "dummy" ) or die "first ls: $!"; ls( "dummy" ) or die "second ls: $!";` [download] and get different error messages: `$ rm dummy $ perl shell-test.pl touch: Illegal seek at shell-test.pl line 6. $ touch dummy $ perl shell-test.pl touch: Illegal seek at shell-test.pl line 6.` [download]	[reply] [d/l] [select]
Re: Re: Shell usable? by axelrose (Scribe) on Jul 02, 2002 at 15:42 UTC
You're right. This is a silly example but imagine some intermedia processing with the dummy file ... the error pops up the second time I use the $sh->ls.	[reply]