how to pass tcsh variable to perl one-liner

Question

can you please tell me how to pass the cshell variable to a perl one liner? i expect the script to print out AAA but it ends up giving me an error: Substitution replacement not terminated at -e line 1.

#!/usr/bin/tcsh -fb

set myvar = "AAA"
perl -e "print $myvar"

the more complex case for my script.

#!/usr/bin/tcsh -fb

set myvar = "AAA"
perl -ne 'if (/$myvar/) {s/m1/m2/g}' fileA

actually this is just a simplified version of my script, i would like to process an input file said fileA....my script is something like: perl -ne 'if (/$myvar/) {s/m1/m2/g} fileA — user466130, Aug 29 '13 at 04:13
possible duplicate of [How can I pass on my Bash loop variable to the Perl interpreter?](http://stackoverflow.com/questions/8974493/how-can-i-pass-on-my-bash-loop-variable-to-the-perl-interpreter) — Zaid, Aug 29 '13 at 06:11

score 1 · Answer 1 · answered Aug 29 '13 at 04:57

Environment variables from the host system are available in Perl's %ENV variable. But to mark a variable as inheritable you have to use csh's setenv builtin instead of set.

% setenv myvar AAA
% perl -e 'print $ENV{myvar}'
AAA

(Note the single quotes in the argument to perl -e)

score 1 · Answer 2 · answered Aug 29 '13 at 05:25

Your perl statement is print 'AAA', so you need to pass the single quote in.

set myvar = "AAA"
perl -e "print '$myvar'"

In the other case, you need to use double-quotes to let Perl get the value of your variable.

set myvar = "AAA"
perl -ne "if (/$myvar/) {s/m1/m2/g}" fileA

score 0 · Answer 3 · answered Aug 29 '13 at 04:12

0

You can pass myvar as command line argument to your perl program.

answered Aug 29 '13 at 04:12

Bill

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hi Bill. see my comment above – user466130 Aug 29 '13 at 04:15
Can you please share some code to help me understand. Can you pass the filename as an argument to the perl script? – Bill Aug 29 '13 at 04:18
#!/usr/bin/tcsh -fb set myvar = "AAA" perl -ne 'if (/$myvar/) {s/m1/m2/g}' – user466130 Aug 29 '13 at 04:22
Can you pass `myVar` as an argument and use `ARGV[0]` instead of `$myvar`? – Bill Aug 29 '13 at 04:23
can you show me how to pass both myvar and fileA to the perl 1liner? – user466130 Aug 29 '13 at 04:24
BTW, if all you are doing is `search and replace`, you may consider using `sed -i` or something similar along these lines. – Bill Aug 29 '13 at 04:24
You can pass both of them as command line arguments. Pls look at this -- http://stackoverflow.com/questions/3321829/how-do-i-best-pass-arguments-to-a-perl-one-liner – Bill Aug 29 '13 at 04:25
does SED support paragraph mode? like perl -00 ? – user466130 Aug 29 '13 at 04:26
This may be useful -- http://stackoverflow.com/questions/16385720/print-only-the-first-word-of-each-paragraph-using-sed – Bill Aug 29 '13 at 04:27

how to pass tcsh variable to perl one-liner

3 Answers3