exchanging data between shell script and perl -e

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

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Re: exchanging data between shell script and perl -e by kschwab (Vicar) on Jul 25, 2001 at 16:32 UTC
I suspect that this doesn't work because the "a" and "b" variables aren't in the environment. Try adding "export a;export b" in between the "b=" and "c=" lines. Or you could just pass them on the command line: c=`perl -e 'if ( $ARGV[0] < $ARGV[1]} ) { print "1\n"; } else { print +"0\"; }' $a $b` [download] Or, since you are using perl anyway, replace this toplevel shell script with a perl script, and open the pipes from perl.	[reply] [d/l]
Re: Re: exchanging data between shell script and perl -e by Sinister (Friar) on Jul 25, 2001 at 16:40 UTC
The export works just fine! Thank you! <update> setenv works even beter! </update> Sinister greetings. perldoc -q $_	[reply]
Re: Re: Re: exchanging data between shell script and perl -e by PrakashK (Pilgrim) on Jul 25, 2001 at 18:12 UTC
export and setenv are both doing the same thing: adding the variable to your environment, making them accessible to other processes running under the same environment. You use one or the other depending on what shell you are using. The Bourne shell, Korn Shell, bash etc. support 'export'. The C shell and its variants (tcsh etc.) support 'setenv'. I am not sure if any of the shells support both of them, though.	[reply]
Re: exchanging data between shell script and perl -e by Jouke (Curate) on Jul 25, 2001 at 15:57 UTC
First off, you can pass data to perl using normal piping like: `ls -l \|perl -ne "print if /bla/"` [download] Second, if you want to let Perl exit with a status code, you can use exit. I hope this answers your question. Jouke Visser, Perl 'Adept' Using Perl to help the disabled: pVoice and pStory	[reply] [d/l]
Re: Re: exchanging data between shell script and perl -e by Sinister (Friar) on Jul 25, 2001 at 16:01 UTC
This is one option, but I sort of have my mind set on the option I mentioned... If, for what reason what so ever this can't be done I will certainly use this option. But I figured the first to be more readable... Sinister greetings. perldoc -q $_	[reply]
Re: exchanging data between shell script and perl -e by converter (Priest) on Jul 25, 2001 at 18:46 UTC
The "proper" way to do this, from the bash-scripting presepective, is probably to use exit() so that you my test the exit status just as you would with other commands: `$ a=foo b=bar; export a b; perl -le 'exists $ENV{a} && exists $ENV{b} +? exit 0 : exit 1' && echo 'success' success` [download] You can also find the exit status in the shell's `$? variable:` `$ a=foo b=bar; export a b; perl -le 'exists $ENV{a} && exists $ENV{b} +? exit 0 : exit 1'; echo "exit status: $?" exit status: 0` `[download]` `conv`	[reply] [d/l] [select]