"command options" suggests several distinct topics:
Certain considerations are common to all these, and are convenient to treat here in a unified way.
Question: In C, for Tcl, using the newer objc, objv API, how do I parse options? I would have thought people would need to do this all the time, but I can't find anything. Needs to handle args, options, required optional etc. Speed is high on the priority list...
If you can use the Tk library, try Tk_SetOptions and its assorted support functions. It would be nice if something like this were in the Tcl library, for those times when one doesn't have Tk around. If you can't use Tk, consider doing option handling in a Tcl front-end to your C function.
[Many people write their own "... -arg1 val1 -arg2 val2 ..." processing, because it's so easy to use Tcl associative arrays (see "Arrays / Hash Maps") simply as the "optional arguments" section in Tcl Gems does ...]
Here is the start of some code to show at least one method of doing command line parsing. Hopefully people will contribute other samples as appropriate.
# If this script was executed, and not just "source"'d, handle argv
if { [string compare [info script] $argv0] == 0} {
while {[llength $argv] > 0 } {
set flag [lindex $argv 0]
switch -- $flag {
"-bool" {
set bool 1
set argv [lrange $argv 1 end]
}
"-option" {
set value [lindex $argv 1]
set argv [lrange $argv 2 end]
}
default { break }
}
}
}
foreach file $argv {
puts "[format "file: %s" $file]"
}A quick and dirty way uses one-liners like this:
if [regexp " -x" $::argv] {# do the X thing} ;# RSIf your values come in pairs (like -option value), I usually use the following code for parsing them:
foreach {option value} $argument_list {
switch -glob -- $option {
-opt* {set opt $val}
-otheropt* {set otheropt $val}
default {error "Unkown option $option!"}
}
}A related topic: "Syntax parsing in Tcl".