Getopt::Long (3p) - Extended processing of command line options
Getopt::Std, getopt, getopts (3p) - Process single-character switches with switch clustering
OpenBSD::Getopt (3p) - Process single-characters switches
getopt (1) - parse command options
getopt (3) - get option character from command line argument list
getopt_long, getopt_long_only (3) - get long options from command line argument list
sobind, soclose, soconnect, socreate, soreceive, sosetopt, sogetopt, sosend, soshutdown (9) - kernel socket interface
AppConfig::Getopt (3p) - Perl5 module for processing command line arguments via delegation to Getopt::Long.
gnugetopt (1) - parse command options (enhanced)
sasl_getopt_t (3) - The SASL get option callback