GETSUBOPT(3) BSD Library Functions Manual GETSUBOPT(3)NAMEgetsubopt — 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 argu‐
ment 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'' por‐
tion 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 ALSOgetopt(3), strsep(3)HISTORY
The getsubopt() function first appeared in 4.4BSD.
BSD June 9, 1993 BSD