The good thing about Perl regex is that you don't have to write the entire regex in one go, you can build it part by part programmatically. I often construct my regex in the maner as shown below to improve readability (at least to myself) and maintainability:
use strict;
use warnings;
# allowed prompt characters
my $prompt_regex = '[>$%@~# ]';
# allowed characters in the prompt
my $allowed_regex = '[\w@\-\.]*';
# a list of allowed prompt patterns
my @patterns = (
'\[?' . $allowed_regex . $prompt_regex . '\]?',
quotemeta '\\[\\e[0m\\] [0m',
);
# build my regex dynamically
my $regex = '(' . join('|',@patterns) .')\s?';
# test the regex
print "regex: /$regex/\n\n";
while (<DATA>) {
chomp;
/$regex/ && printf "%-30smatched: %s\n", $_, $1;
}
__DATA__
roger@www.foo.com# blah
roger@www.foo~ crap crap
[roger@www#] blah blah foo
[roger@www.foo~] crap crap
\[\e[0m\] [0m foo bar
And the output -
regex: /(\[?[\w@\-\.]*[>$%@~# ]\]?|\\\[\\e\[0m\\\]\ \[0m)\s?/
roger@www.foo.com# blah matched: roger@www.foo.com#
roger@www.foo~ crap crap matched: roger@www.foo~
[roger@www#] blah blah foo matched: [roger@www#]
[roger@www.foo~] crap crap matched: [roger@www.foo~]
\[\e[0m\] [0m foo bar matched: \[\e[0m\] [0m