int
getsubopt(
char **optionp
, char * const *tokens
, char **valuep
)
)
function
parses a string containing tokens delimited by one or more tab, space or
comma
(`,')
characters.
It is intended for use in parsing groups of option arguments provided
as part of a utility command line.
The argument
optionp
is a pointer to a pointer to the string.
The argument
tokens
is a pointer to a
NULL
-terminated
array of pointers to strings.
The
getsubopt()
function
returns the zero-based offset of the pointer in the
tokens
array referencing a string which matches the first token
in the string, or -1 if the string contains no tokens or
tokens
does not contain a matching string.
If the token is of the form ``name=value'', the location referenced by
valuep
will be set to point to the start of the ``value'' portion of the token.
On return from
getsubopt(),
optionp
will be set to point to the start of the next token in the string,
or the null at the end of the string if no more tokens are present.
The external variable
suboptarg
will be set to point to the start of the current token, or
NULL
if no
tokens were present.
The argument
valuep
will be set to point to the ``value'' portion of the token, or
NULL
if no ``value'' portion was present.
char *tokens[] = {
#define ONE 0
"one",
#define TWO 1
"two",
NULL
};
...
extern char *optarg, *suboptarg;
char *options, *value;
while ((ch = getopt(argc, argv, "ab:")) != -1) {
switch(ch) {
case 'a':
/* process ``a'' option */
break;
case 'b':
options = optarg;
while (*options) {
switch(getsubopt(&options, tokens, &value)) {
case ONE:
/* process ``one'' sub option */
break;
case TWO:
/* process ``two'' sub option */
if (!value)
error("no value for two");
i = atoi(value);
break;
case -1:
if (suboptarg)
error("unknown sub option %s",
suboptarg);
else
error("missing sub option");
break;
}
break;
}
)
function first appeared in
4.4BSD.