NAME
getsubopt —
get sub options from an
argument
SYNOPSIS
#include
<stdlib.h>
extern char *suboptarg;
int
getsubopt(char
**optionp, char * const
*tokens, char
**valuep);
DESCRIPTION
The
getsubopt()
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 NUL 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 *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("illegal sub option %s",
suboptarg);
else
error("missing sub option");
break;
}
}
break;
}
}
SEE ALSO
HISTORY
The getsubopt() function first appeared in
4.4BSD.