need help:insert a line in a textfile

star7 has asked for the wisdom of the Perl Monks concerning the following question:

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Re: need help:insert a line in a textfile by jmcnamara (Monsignor) on Sep 11, 2003 at 13:19 UTC
As a one-liner (with backup), see perlrun: `perl -i.bak -pe 'print "New line here\n" if $. == 1' file` [download] -- John.	[reply] [d/l]
Re: need help:insert a line in a textfile by broquaint (Abbot) on Sep 11, 2003 at 13:14 UTC
That's just a simple perl one-liner e.g `perl -pi -e '$. == 1 and print $/' textfile` [download] See. `perlrun` and `perlvar` for more info. HTH `_________ broquaint`	[reply] [d/l]
Re: need help:insert a line in a textfile by Zaxo (Archbishop) on Sep 11, 2003 at 13:23 UTC
There is not a single command to insert a line into a file. The Tie::File module gives a convenient way to do it. `use Tie::File; my $newline = "whatever"; { tie my @array, 'Tie::File', '/path/to/file.txt'; unshift @array, $newline; }` [download] If you wish to insert a line elsewhere, splice works with that. After Compline, Zaxo	[reply] [d/l]
Re: need help:insert a line in a textfile by Abigail-II (Bishop) on Sep 11, 2003 at 13:26 UTC
And an alternative for a test on $. for each line of the file: `$ perl -pwle 'BEGIN {print "First Line!"}' your_file` [download] Or even `$ perl -Mstrict='}, print +("First Line"), qw {' -pwle1 your_file` [download] Abigail	[reply] [d/l] [select]
Re: Re: need help:insert a line in a textfile by jmcnamara (Monsignor) on Sep 11, 2003 at 13:32 UTC
Not testing `$.` is more efficient but it is worth pointing out that this doesn't work with -i. -- John.	[reply]
Re: need help:insert a line in a textfile by perl_seeker (Scribe) on Sep 12, 2003 at 10:58 UTC
You can write the following lines in your Perl editor and then execute it: `my $line="Whatever line you want to insert"; open FH, '>mytextfile.txt' or die $!; print FH $line; close FH;` [download] Thanx:)	[reply] [d/l]