1GETSUBOPT(3)               Library Functions Manual               GETSUBOPT(3)
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NAME

6       getsubopt - get sub options from an argument
7

SYNOPSIS

9       #include <stdlib.h>
10
11       extern char *suboptarg
12
13       int
14       getsubopt(optionp, tokens, valuep)
15       char **optionp;
16       char **tokens;
17       char **valuep;
18

DESCRIPTION

20       The getsubopt() function parses a string containing tokens delimited by
21       one or more tab, space or comma (`,') characters.  It is  intended  for
22       use in parsing groups of option arguments provided as part of a utility
23       command line.
24
25       The argument optionp is a pointer to a  pointer  to  the  string.   The
26       argument  tokens is a pointer to a NULL-terminated array of pointers to
27       strings.
28
29       The getsubopt() function returns the zero-based offset of  the  pointer
30       in  the tokens array referencing a string which matches the first token
31       in the string, or, -1 if the string contains no tokens or  tokens  does
32       not contain a matching string.
33
34       If  the token is of the form ``name=value'', the location referenced by
35       valuep will be set to point to the start of the  ``value''  portion  of
36       the token.
37
38       On  return  from getsubopt(), optionp will be set to point to the start
39       of the next token in the string, or the null at the end of  the  string
40       if no more tokens are present.  The external variable suboptarg will be
41       set to point to the start of the current token, or NULL  if  no  tokens
42       were  present.   The  argument  valuep  will  be  set  to  point to the
43       ``value'' portion of the token, or NULL if  no  ``value''  portion  was
44       present.
45

EXAMPLE

47       char *tokens[] = {
48            #define   ONE  0
49                 "one",
50            #define   TWO  1
51                 "two",
52            NULL
53       };
54
55       ...
56
57       extern char *optarg, *suboptarg;
58       char *options, *value;
59
60       while ((ch = getopt(argc, argv, "ab:")) != -1) {
61            switch(ch) {
62            case 'a':
63                 /* process ``a'' option */
64                 break;
65            case 'b':
66                 options = optarg;
67                 while (*options) {
68                      switch(getsubopt(&options, tokens, &value)) {
69                      case ONE:
70                           /* process ``one'' sub option */
71                           break;
72                      case TWO:
73                           /* process ``two'' sub option */
74                           if (!value)
75                                error("no value for two");
76                           i = atoi(value);
77                           break;
78                      case -1:
79                           if (suboptarg)
80                                error("illegal sub option %s",
81                                  suboptarg);
82                           else
83                                error("missing sub option");
84                           break;
85                 }
86                 break;
87            }
88

SEE ALSO

90       getopt(3), strsep(3)
91

HISTORY

93       The getsubopt() function first appeared in 4.4BSD.
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974.4 Berkeley Distribution      January 12, 1996                   GETSUBOPT(3)