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Read and delete text between two strings in perl

Answer 1

A:

Specify the beginning and ending strings via the environment, and the file to use on the perl command line:

export START_STRING='abc def'
export END_STRING='ghi jkl'
perl -0777 -i -wpe's/\Q$ENV{START_STRING}\E(.*)\Q$ENV{END_STRING}\E/s;print STDERR $1' file_to_use 2>savedtext

ysth 2010-08-25 02:40:22

when I type that in command prompt it is not saving the text into savedtext. When I type echo $savedtext I get a blank space. It does however delete the correct text--but only if string1 is NOT the first word. If string1 IS the first word then it deletes everything, but still no savedtext.

Feynman 2010-08-25 03:26:14

@Feynman: the $1 is the special character w/ the stored text

vol7ron 2010-08-25 03:29:18

Better example: `$text="foostringbar"; $text =~ s/foo(.*?)bar//i; $cut=$1; print $cut;`

vol7ron 2010-08-25 03:32:42

@Feynman: perl version, OS? Can you paste the actual command that you ran that doesn't seem to work?

ysth 2010-08-25 04:46:33

Perl version: 5.10.0, OS: Debian.Gladly. It's actually part of a shell script (I am so used to making everything a shell script I forget I can compile it with perl directly).#!/bin/bashperl -0777 -i -wpe's/$ARGV[0](.*)$ARGV[1]//s;print STDERR $1' $3 2>savetextActually, just having the module execute whatever is between the strings as a shell script rather than saving it as a variable would be ideal. Saving is a useful tool, but not directly what I need.

Feynman 2010-08-25 04:59:33

And vol7ron--how to I get $text to be the text of a file rather than an input? I gave putting the file name in <> but as you probably would have guessed that did not work.

Feynman 2010-08-25 04:59:54

ah; I was using the command line argument for the filename to change; that's incompatible with using them for the strings to find. can you have those use environment variables? also, if they may have meta characters that need quoting, do: `s/\Q$ENV{START_STRING}\E(.*)\Q$ENV{END_STRING}\E/...`

ysth 2010-08-25 05:47:04

what comes after the ... ? Bash does not like it if I past ins/\Q$ENV{START_STRING}\E(.*)\Q$ENV{END_STRING}\E/...It doesn't like the "..." I understand that is a placeholder for something obvious. Unfortunately, I do not know much perl. I am just getting the necessary functions for my program.

Feynman 2010-08-25 06:05:33

… means same as above, starting with `print`

daxim 2010-08-25 06:51:44

nope. It says next token ???#!/bin/perls/\Q$ENV{this better work}\E(.*)\Q$ENV{end of script}\E/print STDERR $1 Desktop/test 2>savedtext

Feynman 2010-08-25 16:55:16

@Feynman: that's not right; updating my answer with a full example

ysth 2010-08-25 21:47:24

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Read and delete text between two strings in perl

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