Useful Perl
print scalar( localtime( [unixtime] )) print a human readable date/time from a unix time stamp
use lib '/path/to/look/in'; includes a library that is not in the perl include directories (@INC)
my $value ||= "Default"; set a variable if not set
perl -V list directories in perl include array (@INC)
$value =~ s/^\s+//; remove leading whitespace
$value =~ s/\s+$//; remove trailing whitespace
perl -e 'print scalar localtime( [unixtime] ), "\n"' command line translation of unixtime to human readable
eval { $@=0; require '/file/to/be/';}; if( $@ ){ #handle error } debugging scheme
perldoc [module name] useful perl documentation
CPAN archive for perl modules
perl -pi -e "s/old/new/g" filename command line string replacement in filenemt
/^[a-zA-Z0-9_.\-]+@[a-zA-Z0-9_.\-]+$/ Regular expression to test for valid email address
my $var = 42; $result = "before${var}after"; How to incorporate a variable in a string.