#!/bin/perl
#
use strict;
local $/="\n\n";
my $match = shift @ARGV;
my $subst = shift @ARGV;
my $save;
while (defined (my $paragraph = <>))
{
$paragraph =~ s/\n+$//;
$paragraph .= "\n";
my $user = ($paragraph =~ m/(\w+)\n/)[0];
if ($match eq $user)
{
$save = $paragraph;
$save =~ s/\b$user\b/$subst/g
};
print "$paragraph\n"
}
print "$save" if defined $save;
exit 0
Используйте это так
script.pl user2 user4 <file