Changing file contents

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

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Re: Changing file contents by rnahi (Curate) on May 29, 2003 at 08:06 UTC
This one liner `perl -i.bak -pe 's/123456/234165/' filename` [download] will change only one occurrence of the pattern, modify your file in place and save the old one with a ".bak" extension. To change every occurrence of the pattern, use `s/123456/234165/g` [download]	[reply] [d/l] [select]
Re: Changing file contents by zby (Vicar) on May 29, 2003 at 08:53 UTC
You have rnahi's answer - it's a shortcut, no offence but I think it's a bit too magic for your level of perl mastery. Here are my instructions: Learn how to open a file handle - `perldoc -f open` Learn how to read the file content - `perldoc perlop` look for the `<>` operator. Learn Perl regular expressions - `perldoc perlre` Learn the substitution operator `perldoc perlop` look for `s/PATTERN/REPLACEMENT/egimosx` Learn how to write to a file - `perldoc -f print` Then the progarm should be obvious.	[reply] [d/l] [select]