Fix up sched.h for XPG7.
[glibc.git] / manual / examples / argp-ex4.c
blob8628a235dda80bffac8039981d26d608ad18679c
1 /* Argp example #4 -- a program with somewhat more complicated options */
3 /* This program uses the same features as example 3, but has more
4 options, and somewhat more structure in the -help output. It
5 also shows how you can `steal' the remainder of the input
6 arguments past a certain point, for programs that accept a
7 list of items. It also shows the special argp KEY value
8 ARGP_KEY_NO_ARGS, which is only given if no non-option
9 arguments were supplied to the program.
11 For structuring the help output, two features are used,
12 *headers* which are entries in the options vector with the
13 first four fields being zero, and a two part documentation
14 string (in the variable DOC), which allows documentation both
15 before and after the options; the two parts of DOC are
16 separated by a vertical-tab character ('\v', or '\013'). By
17 convention, the documentation before the options is just a
18 short string saying what the program does, and that afterwards
19 is longer, describing the behavior in more detail. All
20 documentation strings are automatically filled for output,
21 although newlines may be included to force a line break at a
22 particular point. All documentation strings are also passed to
23 the `gettext' function, for possible translation into the
24 current locale. */
26 #include <stdlib.h>
27 #include <error.h>
28 #include <argp.h>
30 const char *argp_program_version =
31 "argp-ex4 1.0";
32 const char *argp_program_bug_address =
33 "<bug-gnu-utils@@prep.ai.mit.edu>";
35 /* Program documentation. */
36 static char doc[] =
37 "Argp example #4 -- a program with somewhat more complicated\
38 options\
39 \vThis part of the documentation comes *after* the options;\
40 note that the text is automatically filled, but it's possible\
41 to force a line-break, e.g.\n<-- here.";
43 /* A description of the arguments we accept. */
44 static char args_doc[] = "ARG1 [STRING...]";
46 /* Keys for options without short-options. */
47 #define OPT_ABORT 1 /* --abort */
49 /* The options we understand. */
50 static struct argp_option options[] = {
51 {"verbose", 'v', 0, 0, "Produce verbose output" },
52 {"quiet", 'q', 0, 0, "Don't produce any output" },
53 {"silent", 's', 0, OPTION_ALIAS },
54 {"output", 'o', "FILE", 0,
55 "Output to FILE instead of standard output" },
57 {0,0,0,0, "The following options should be grouped together:" },
58 {"repeat", 'r', "COUNT", OPTION_ARG_OPTIONAL,
59 "Repeat the output COUNT (default 10) times"},
60 {"abort", OPT_ABORT, 0, 0, "Abort before showing any output"},
62 { 0 }
65 /* Used by @code{main} to communicate with @code{parse_opt}. */
66 struct arguments
68 char *arg1; /* @var{arg1} */
69 char **strings; /* [@var{string}@dots{}] */
70 int silent, verbose, abort; /* @samp{-s}, @samp{-v}, @samp{--abort} */
71 char *output_file; /* @var{file} arg to @samp{--output} */
72 int repeat_count; /* @var{count} arg to @samp{--repeat} */
75 /* Parse a single option. */
76 static error_t
77 parse_opt (int key, char *arg, struct argp_state *state)
79 /* Get the @code{input} argument from @code{argp_parse}, which we
80 know is a pointer to our arguments structure. */
81 struct arguments *arguments = state->input;
83 switch (key)
85 case 'q': case 's':
86 arguments->silent = 1;
87 break;
88 case 'v':
89 arguments->verbose = 1;
90 break;
91 case 'o':
92 arguments->output_file = arg;
93 break;
94 case 'r':
95 arguments->repeat_count = arg ? atoi (arg) : 10;
96 break;
97 case OPT_ABORT:
98 arguments->abort = 1;
99 break;
101 case ARGP_KEY_NO_ARGS:
102 argp_usage (state);
104 case ARGP_KEY_ARG:
105 /* Here we know that @code{state->arg_num == 0}, since we
106 force argument parsing to end before any more arguments can
107 get here. */
108 arguments->arg1 = arg;
110 /* Now we consume all the rest of the arguments.
111 @code{state->next} is the index in @code{state->argv} of the
112 next argument to be parsed, which is the first @var{string}
113 we're interested in, so we can just use
114 @code{&state->argv[state->next]} as the value for
115 arguments->strings.
117 @emph{In addition}, by setting @code{state->next} to the end
118 of the arguments, we can force argp to stop parsing here and
119 return. */
120 arguments->strings = &state->argv[state->next];
121 state->next = state->argc;
123 break;
125 default:
126 return ARGP_ERR_UNKNOWN;
128 return 0;
131 /* Our argp parser. */
132 static struct argp argp = { options, parse_opt, args_doc, doc };
134 int main (int argc, char **argv)
136 int i, j;
137 struct arguments arguments;
139 /* Default values. */
140 arguments.silent = 0;
141 arguments.verbose = 0;
142 arguments.output_file = "-";
143 arguments.repeat_count = 1;
144 arguments.abort = 0;
146 /* Parse our arguments; every option seen by @code{parse_opt} will be
147 reflected in @code{arguments}. */
148 argp_parse (&argp, argc, argv, 0, 0, &arguments);
150 if (arguments.abort)
151 error (10, 0, "ABORTED");
153 for (i = 0; i < arguments.repeat_count; i++)
155 printf ("ARG1 = %s\n", arguments.arg1);
156 printf ("STRINGS = ");
157 for (j = 0; arguments.strings[j]; j++)
158 printf (j == 0 ? "%s" : ", %s", arguments.strings[j]);
159 printf ("\n");
160 printf ("OUTPUT_FILE = %s\nVERBOSE = %s\nSILENT = %s\n",
161 arguments.output_file,
162 arguments.verbose ? "yes" : "no",
163 arguments.silent ? "yes" : "no");
166 exit (0);