RSS FeedPerl: Command Line Options Without GetOpt::Std
drks — Fri, 2007-09-14 06:41
Summary:
At times you may need to write a script that needs to be completely portable. Meaning, you can't rely on modules that may not be included stock with the operating system.
On Redhat, GetOpt::Std is not included in the stock installation (at least not where I work). Therefore, I needed just a quick and simple way to parse command line options into the script.
The following is an example 'test.pl' of how I did this:
#!/usr/bin/perl -w
use strict;
my $ip_address;
my $mac_address;
my $hostname;
my $debug = 0;
# Sort the options
while (@ARGV) {
if($ARGV[0] eq '-h' || $ARGV[0] eq '--help') {
shift(@ARGV);
&display_help;
exit;
}
if($ARGV[0] eq '-i' || $ARGV[0] eq '--ip') {
shift(@ARGV);
$ip_address = shift(@ARGV);
next;
}
if($ARGV[0] eq '-m' || $ARGV[0] eq '--mac') {
shift(@ARGV);
$mac_address = shift(@ARGV);
next;
}
if($ARGV[0] eq '-H' || $ARGV[0] eq '--hostname') {
shift(@ARGV);
$hostname = shift(@ARGV);
next;
}
if($ARGV[0] eq '-D' || $ARGV[0] eq '--debug') {
shift(@ARGV);
$debug = 1;
next;
}
}
sub display_help() {
my $option = '';
my $description = '';
my %help_menu = ();
print "\n";
print "USAGE:\n\n";
print "./test.pl -(OPTION) <VALUE>\n\n";
print "OPTIONS:\n\n";
format STDOUT =
@<<<<<<<<<<< @<<<<<<<<<<<<<<<<<<<<<<<<
$option, $description
.
%help_menu = (
'-h,--help' => 'display help',
'-i,--ip' => 'ip address',
'-m,--mac' => 'mac address',
'-h,--hostname' => 'hostname',
'-D,--debug' => 'toggle debug info'
);
foreach(keys %help_menu) {
$option = $_;
$description = $help_menu{$_};
write();
}
print "\n\n";
}
print "IP Address : $ip_address\n";
print "MAC Address : $mac_address\n";
print "Hostname : $hostname\n";
New comers to Perl may need to reference the Array data type and Shift documentation to clarify the situation.
Now, lets see what it looks like:
[wdierkes@dev ~]$ ./test.pl --help
USAGE:
./test.pl -(OPTION) <VALUE>
OPTIONS:
-m,--mac mac address
-D,--debug toggle debug info
-h,--help display help
-h,--hostnam hostname
-i,--ip ip address
[wdierkes@dev ~]$ ./test.pl -H test.example.com \
--ip 192.168.0.102 \
--mac 00:5b:18:43:1n:9c
IP Address : 192.168.0.102
MAC Address : 00:5b:18:43:1n:9c
Hostname : test.example.com