Another possibility is to simply
require the modules you need and
let them define subroutines and such. For example, in the program
from which my
simple command parser comes from, the commands
are loaded from a directory in which files with names starting
with 2 digist and ending with ".pl" are assumed to define the appropriate
subroutines and variables. Here's a simplified version of what
I use to load them. Notice how I also incorporate variables
declared in each module (in this case %COMMAND) into another
global hash.
# Load command modules
if (-d $cmddir) {
opendir(CMDDIR, $cmddir)
or die "Error opening '$cmddir': $!\n";
# Get only .pl files that start with 2 digits and that contain onl
+y
# alphanumerics, underscores, hyphens or dots in their names.
my @cmdfiles=map { (/^(\d{2}[-\w.]+\.pl)$/ && $1) || () } readdir(
+CMDDIR);
closedir(CMDDIR);
# Read each file and incorporate its %COMMANDS into %ALLCOMMANDS
my $cmdfile;
if (@cmdfiles) {
foreach $cmdfile (@cmdfiles) {
local %COMMANDS;
eval "require '$cmddir/$cmdfile'";
die "Error loading '$cmddir/$cmdfile': $!\n" if $@;
my ($k,$v);
# Incorporate commands
while (($k,$v)=each(%COMMANDS)) {
$ALLCOMMANDS{$k}=$v;
}
}
}
else {
# Print warning, but continue, because builtin commands can stil
+l
# be used (not very useful, but...)
warn "Warning: No command files found in directory '$cmddir'\n";
}
} else {
die "Fatal: Could not find commands dir '$cmddir'\n";
}