GETSUBOPT(3) | Library Functions Manual | GETSUBOPT(3) |
getsubopt
—
#include <stdlib.h>
extern char *suboptarg
int
getsubopt
(char
**optionp, char * const
*tokens, char
**valuep);
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 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; }
getsubopt
() function first appeared in
4.4BSD, and is included in IEEE Std
1003.1-2008 (“POSIX.1”).
August 15, 2018 | NetBSD 9.2 |