match a line and edit it

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

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Re: match a line and edit it by toolic (Bishop) on Mar 17, 2010 at 01:19 UTC
One way to modify a file in-place is to use Tie::File. The following will replace all lines which have the string 'foo' with the line 'This is now bar': `use strict; use warnings; use Tie::File; tie my @array, 'Tie::File', 'file.txt' or die $!; for (@array) { if (/foo/) { $_ = 'This is now bar'; } } untie @array;` [download]	[reply] [d/l]
Re^2: match a line and edit it by Anonymous Monk on Mar 17, 2010 at 01:41 UTC
Thanks much. That worked.	[reply]
Re^2: match a line and edit it by Anonymous Monk on Mar 17, 2010 at 23:33 UTC
May I know, How I can add a new line char with the line I am adding, like `if (/foo/) { $_ = "This is now bar\n"; }` [download] I tried the above, but is not adding a new line, I tried to set autochomp => 0 also.	[reply] [d/l]
Re: match a line and edit it by almut (Canon) on Mar 17, 2010 at 01:34 UTC
`$ perl -i.bak -pe 's/^.foo.$/bar/' file` [download] "foo" is the pattern to search for in the line. The whole line will be replaced with "bar". `-p` is equivalent to putting `while (<>) { ...; print }` around the code. `-i.bak` does "in-place" editing, creating a backup file with extension `.bak`.	[reply] [d/l] [select]