NAME
getsubopt —
get sub options from an
argument
LIBRARY
Standard C Library (libc, -lc)
SYNOPSIS
#include
<stdlib.h>
extern char *suboptarg;
int
getsubopt(char **optionp,
char *const *keylistp, char
**valuep);
DESCRIPTION
The
getsubopt()
function parses a string containing tokens that are delimited by one or more
tab, space, or comma (‘,’) characters.
It is intended for use in parsing groups of option arguments that are
provided as part of a utility command line.
The argument optionp is a pointer to a
pointer to the string. The argument keylistp 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
keylistp array, referencing a string which matches the
first token in the string
or -1 if the string contains no tokens or keylistp 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.
EXAMPLES
char *keylistp[] = {
#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, keylistp, &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("illegal sub option %s",
suboptarg);
else
error("missing sub option");
break;
}
break;
}
SEE ALSO
HISTORY
The getsubopt() function first appeared in
4.4BSD.