getopt(3tlib)

getopt -- parse UNIX command line options

Synopsis

global argv optind optarg opterr
set argc [llength argv]
getopt $argc $argv $optstring

Description

getopt returns the next option letter in argv that matches a letter in optstr. It supports all the rules of the command syntax standard.

optstring must contain the option letters the command using getopt recognizes; if a letter is followed by a colon, the option is expected to have an argument, or group of arguments, which must be separated from it by white space.

Arguments

argc: count of list elements in argv, e.g. [llength argv]
argv: Tcl global, the command line argument vector.
optstring: list of valid single-letter options.

Globals

argv: Tcl command line argument vector
optind: Tcl list index in argv of next argument to be processed.
optarg: Tcl list index in argv of option argument.
opterr: boolean controlling error message on stderr. Defaults to 1. Set to 0 to suppress.

Return values

The next valid option letter from argv. ``?'' for an invalid option or missing option argument. ``-1'' when all command line options have been parsed. optarg points to the option argument if the returned option letter takes such and argument and it is present in argv.

optind is left pointing to the next argument in argv.

References

getopt(3C).

Notices

See getopt(3C) for complete details about valid command line syntax.