getopt
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| + | # $EPIC: getopt.txt,v 1.4 2007/03/02 02:32:04 jnelson Exp $ | ||
| + | ======Synopsis:====== | ||
| + | $__getopt__(<optopt-var> <optarg-var> <option-list> <argument-list>) | ||
| + | |||
| + | ======Technical:====== | ||
| + | * The <option-list> argument is a [[what is a word|dword]] which is different from most function arguments. | ||
| + | * This function should be called as the expression of a [[WHILE]] command. | ||
| + | * If the <optopt-var> argument is omitted the empty string is returned. | ||
| + | * If the <optarg-var> argument is omitted the empty string is returned. | ||
| + | * If the <option-list> argument is omitted the empty string is returned. | ||
| + | * The <optopt-var> argument is taken as the name of a variable in which to put the current option being parsed. | ||
| + | * The <optarg-var> argument is taken as the name of a variable in which to put the current argument being parsed. | ||
| + | * The <option-list> argument is taken as a list of arguments that are to be parsed from <argument-list>. \\ Each character in <option-list> permits an option by that character to be parsed. \\ Each character may be followed by either a single colon which specifies that the option must always be followed by an argument, or a double colon, which specifies that the option may or may not be followed by an argument. | ||
| + | * The <argument-list> argument is taken to be word list of [[what is a word|dwords]], which means double quoted words are supported, and the double quotes are removed. | ||
| + | * The <argument-list> argument is taken as an argument list, perhaps to an alias, that are to be parsed. \\ It is fully parsed the "first time" that $getopt() is called. | ||
| + | * Each and every time any of the arguments to the getopt() function change between one call and the next, \\ it is considered the "first time" that the $getopt() function has been called. | ||
| + | * The return value of the function shall be an indicator of the "next" option found in <argument-list>. \\ The "first time" that $getopt() is called, the first option in <argument-list> is returned. \\ The second time that $getopt() is called, the second option in <argument-list> is returned, and so on. | ||
| + | * Five things can be returned each call to $getopt(). | ||
| + | * The name of an option that does not take an argument: \\ $<optopt-var> contains the name of the option. \\ $<optarg-var> contains the empty string. | ||
| + | * The name of an option that takes an argument: \\ $<optopt-var> contains the name of the option. \\ $<optarg-var> contains the argument to the option. \\ | ||
| + | * A hyphen ('-') indicating an option that takes an argument and was not provided with one: \\ $<optopt-var> contains the name of the option \\ $<optarg-var> contains the empty string. | ||
| + | * A bang ('!') indicating an option that was not one of the options listed in <option-list>: \\ $<optopt-var> contains the name of the string \\ $<optarg-var> contains the empty string. | ||
| + | * An empty string indicates processing is complete or internal error: \\ $<optopt-var> is empty. \\ $<optarg-var> contains the remaining non-option args. | ||
| + | |||
| + | ======Practical:====== | ||
| + | Useful when you want an alias to accept option flags and you need a | ||
| + | way to parse them easily. See the example section for particulars. | ||
| + | |||
| + | ======Returns:====== | ||
| + | See technical specification for return values. | ||
| + | |||
| + | ======Examples:====== | ||
| + | <file> | ||
| + | alias myalias { | ||
| + | while (option = getopt(optopt optarg "ab:c:" $*)) { | ||
| + | switch ($option) { | ||
| + | (a) {echo * option "$optopt" used} | ||
| + | (b) {echo * option "$optopt" used - $optarg} | ||
| + | (c) {echo * option "$optopt" used - $optarg} | ||
| + | (!) {echo * option "$optopt" is an invalid option} | ||
| + | (-) {echo * option "$optopt" is missing an argument} | ||
| + | } | ||
| + | } | ||
| + | echo * remaining args: $optarg | ||
| + | } | ||
| + | </file> | ||
getopt.txt ยท Last modified: 2007/03/02 02:32 (external edit)