regex - Regular expression for Password Requirements for PCI Compliance -

here password requirements pci compliance:

• must contain @ least 1 upper case letter
• must contain @ least 1 lower case letter
• must contain @ least 1 number
• must contain @ least 1 special character such #, !, ?, ^, or @.

please tell me how create such regulat expressions? can`t figure out how it

don't single regex. there's no need in single regex, , easier change rules, , easier read, if make multiple regex checks.

if doing in perl, example, you'd do

my $ok =     ($pw =~ /[a-z]/) &&  # has @ least 1 lowercase char     ($pw =~ /[a-z]/) &&  # has @ least 1 uppercase char     ($pw =~ /\d/)    &&  # has @ least 1 digit     ($pw =~ /[#!?^@]);   # has punctuation 

that far easier read later on when have maintain code in future.