Long (very long) version. Use regexen. File process_file_1.pl:
use warnings;
use strict;
die "usage: perl $0 file.name \n" unless @ARGV;
my $filename_in = shift;
print "processing '$filename_in' \n";
my $filename_out = "$filename_in.new";
open my $fh_in, '<', $filename_in or die "opening '$filename_in': $!
+";
open my $fh_out, '>', $filename_out or die "opening '$filename_out': $
+!";
my $sol1 = 'my new stuff';
while (<$fh_in>) {
s{ (SOL) [^\n]* }{$1 $sol1}xmsg;
print $fh_out $_ or die "writing '$filename_out': $!";
}
close $fh_in or die "closing '$filename_in': $!";
close $fh_out or die "closing '$filename_out': $!";
rename $filename_in, "$filename_in.bak" or die "renaming '$filename_in
+': $!";
rename $filename_out, $filename_in or die "renaming '$filename_ou
+t': $!";
This has all the bells and whistles. Shorter versions (including a one-liner) are possible depending on your exact needs. BTW: What version of Perl are you using?
Usage session:
c:\@Work\Perl\monks\samira_saber>dir
Volume in drive C is Acer
Volume Serial Number is 9480-355B
Directory of c:\@Work\Perl\monks\samira_saber
08/14/2017 05:23 PM <DIR> .
08/14/2017 05:23 PM <DIR> ..
08/14/2017 05:04 PM 759 process_file_1.pl
08/14/2017 04:40 PM 46 topol1.au
08/14/2017 04:40 PM 46 topol1.top
3 File(s) 851 bytes
2 Dir(s) 24,485,937,152 bytes free
c:\@Work\Perl\monks\samira_saber>fc topol1.au topol1.top
Comparing files topol1.au and TOPOL1.TOP
FC: no differences encountered
c:\@Work\Perl\monks\samira_saber>type topol1.top
not so SOLITARY
SOLUTION
SOLVE the problem
c:\@Work\Perl\monks\samira_saber>perl process_file_1.pl topol1.top
processing 'topol1.top'
c:\@Work\Perl\monks\samira_saber>dir
Volume in drive C is Acer
Volume Serial Number is 9480-355B
Directory of c:\@Work\Perl\monks\samira_saber
08/14/2017 05:26 PM <DIR> .
08/14/2017 05:26 PM <DIR> ..
08/14/2017 05:04 PM 759 process_file_1.pl
08/14/2017 04:40 PM 46 topol1.au
08/14/2017 05:26 PM 61 topol1.top
08/14/2017 04:40 PM 46 topol1.top.bak
4 File(s) 912 bytes
2 Dir(s) 24,485,937,152 bytes free
c:\@Work\Perl\monks\samira_saber>type topol1.top
not so SOL my new stuff
SOL my new stuff
SOL my new stuff
c:\@Work\Perl\monks\samira_saber>fc topol1.au topol1.top.bak
Comparing files topol1.au and TOPOL1.TOP.BAK
FC: no differences encountered
Please see perlre, perlretut, and perlrequick for (lots and lots of) regex info. See also perlop (update: specifically, the Regexp Quote-Like Operators section) for discussion of the s/// substitution operator.
Give a man a fish: <%-{-{-{-<