sed style file parse from command-line

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

How do (can?) I read in a file and perform substitutions of this sort:

if ($_ =~ /^THIS/) {$_ =~ s/I/A/}
[download]

from the command line, rather than writing an actual script to open and rewrite the file.

Comment on sed style file parse from command-line Download Code

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Re: sed style file parse from command-line by ccn (Vicar) on Dec 28, 2008 at 19:46 UTC
`$perl -pi'orig_*' -e 's/I/A/ if /^THIS/' fileA` [download] see: perldoc perlrun about `-p`, `-i`, `-e` switches	[reply] [d/l] [select]
Re: sed style file parse from command-line by Perlbotics (Archbishop) on Dec 28, 2008 at 19:47 UTC
Maybe something along: `perl -pe ' /^THIS/ && s/I/A/ ' <infile.txt >outfile.txt` [download] ?	[reply] [d/l]
Re: sed style file parse from command-line by superfrink (Curate) on Dec 28, 2008 at 23:45 UTC
On a related note a couple days ago I used the following to delete lines that matched a pattern from a file. `perl -n -i -e 'print unless (m/^.*line-to-remove$/)' fileA` [download]	[reply] [d/l]
Re: sed style file parse from command-line by Anonymous Monk on Dec 28, 2008 at 20:03 UTC
Thanks much gang! Perlmonks rocks as always!	[reply]