How to replace strings in a file from a list?

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

I'm trying replace names in a file, with names from a list included in __DATA__ in the script
below. Now assume I have a text file which contains hundreds of
different names, and I want to replace certain ones with a mapping of say:
JOE -> JOHN
FRED -> FREDERICK
SAM -> SAMANTHA

Do I need to create a hash with the 6 names above before I can replace instances of
JOE, FRED, and SAM, in a text file?

#!/usr/bin/perl -w

use strict;

if ($#ARGV < 0) {
  print "\nUsage: $0 <File>\n\n";
  exit 0;
}

my $userlist = qq{$ARGV[0]};

open(FILE, qq{$userlist}) or die("$!: $userlist");
my @users = <FILE>;
close(FILE);

while ( <DATA> ) {
  print $_;
} 

__DATA__
JOE
FRED
SAM
[download]

Comment on How to replace strings in a file from a list? Download Code

Replies are listed 'Best First'.
Re: How to replace strings in a file from a list? by toolic (Bishop) on Oct 03, 2012 at 02:21 UTC
Do I need to create a hash with the 6 names above before I can replace instances of JOE, FRED, and SAM, in a text file? Yes, that is one way to do it. Give it a try. Also note that you can simplifiy your code a little by eliminating qq around your variables: `my $userlist = $ARGV[0];` [download]	[reply] [d/l]
Re: How to replace strings in a file from a list? by Kenosis (Priest) on Oct 03, 2012 at 03:49 UTC
Here's another option: `use strict; use warnings; use File::Slurp qw/ read_file write_file /; $ARGV[0] or die "\nUsage: $0 <File>\n\n"; my $userlistContents = read_file $ARGV[0]; for ( grep /\S/, <DATA> ) { my ( $before, $after ) = split; $userlistContents =~ s/\b$before\b/$after/g; } write_file "changed_$ARGV[0]", $userlistContents; __DATA__ JOE JOHN FRED FREDERICK SAM SAMANTHA` [download] Using File::Slurp is a nice way to get the file's contents into a scalar upon which global substitutions can be performed. The before and after names in the `__DATA__` area are tab separated. Note that the changed file contents are written to the file named `"changed_$ARGV[0]"`. Hope this helps!	[reply] [d/l] [select]