WvStreams
ex4.c
1/* Argp example #4 - a program with somewhat more complicated options */
2
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.
10
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. */
25
26#include <stdlib.h>
27#include <stdio.h>
28#include <argp.h>
29
30const char *argp_program_version =
31 "argp-ex4 1.0";
32const char *argp_program_bug_address =
33 "<bug-gnu-utils@prep.ai.mit.edu>";
34
35/* Program documentation. */
36static char doc[] =
37 "Argp example #4 -- a program with somewhat more complicated\
38options\
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.";
42
43/* A description of the arguments we accept. */
44static char args_doc[] = "ARG1 [STRING...]";
45
46/* Keys for options without short-options. */
47#define OPT_ABORT 1 /* -abort */
48
49/* The options we understand. */
50static struct argp_option options[] = {
51 {"verbose", 'v', 0, 0, "Produce verbose output", 0},
52 {"quiet", 'q', 0, 0, "Don't produce any output", 0},
53 {"silent", 's', 0, OPTION_ALIAS, 0, 0},
54 {"output", 'o', "FILE", 0,
55 "Output to FILE instead of standard output", 0},
56
57 {0,0,0,0, "The following options should be grouped together:", 0},
58 {"repeat", 'r', "COUNT", OPTION_ARG_OPTIONAL,
59 "Repeat the output COUNT (default 10) times", 0},
60 {"abort", OPT_ABORT, 0, 0, "Abort before showing any output", 0},
61
62 {0, 0, 0, 0, 0, 0}
63};
64
65/* Used by `main' to communicate with `parse_opt'. */
66struct arguments
67{
68 char *arg1; /* ARG1 */
69 char **strings; /* [STRING...] */
70 int silent, verbose, abort; /* `-s', `-v', `--abort' */
71 char *output_file; /* FILE arg to `--output' */
72 int repeat_count; /* COUNT arg to `--repeat' */
73};
74
75/* Parse a single option. */
76static error_t
77parse_opt (int key, char *arg, struct argp_state *state)
78{
79 /* Get the `input' argument from `argp_parse', which we
80 know is a pointer to our arguments structure. */
81 struct arguments *arguments = state->input;
82
83 switch (key)
84 {
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;
100
101 case ARGP_KEY_NO_ARGS:
102 argp_usage (state);
103
104 case ARGP_KEY_ARG:
105 /* Here we know that `state->arg_num == 0', since we
106 force argument parsing to end before any more arguments can
107 get here. */
108 arguments->arg1 = arg;
109
110 /* Now we consume all the rest of the arguments.
111 `state->next' is the index in `state->argv' of the
112 next argument to be parsed, which is the first STRING
113 we're interested in, so we can just use
114 `&state->argv[state->next]' as the value for
115 arguments->strings.
116
117 _In addition_, by setting `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;
122
123 break;
124
125 default:
126 return ARGP_ERR_UNKNOWN;
127 }
128 return 0;
129}
130
131/* Our argp parser. */
132static struct argp argp = { options, parse_opt, args_doc, doc, 0, 0, 0};
133
134int main (int argc, char **argv)
135{
136 int i, j;
137 struct arguments arguments;
138
139 /* Default values. */
140 arguments.silent = 0;
141 arguments.verbose = 0;
142 arguments.output_file = "-";
143 arguments.repeat_count = 1;
144 arguments.abort = 0;
145
146 /* Parse our arguments; every option seen by `parse_opt' will be
147 reflected in `arguments'. */
148 argp_parse (&argp, argc, argv, 0, 0, &arguments);
149
150 if (arguments.abort)
151 {
152 /* The glibc example used error (10, 0, "ABORTED"), but that's
153 not portable. */
154 fprintf(stderr, "ex4: ABORTED\n");
155 exit(10);
156 }
157
158 for (i = 0; i < arguments.repeat_count; i++)
159 {
160 printf ("ARG1 = %s\n", arguments.arg1);
161 printf ("STRINGS = ");
162 for (j = 0; arguments.strings[j]; j++)
163 printf (j == 0 ? "%s" : ", %s", arguments.strings[j]);
164 printf ("\n");
165 printf ("OUTPUT_FILE = %s\nVERBOSE = %s\nSILENT = %s\n",
166 arguments.output_file,
167 arguments.verbose ? "yes" : "no",
168 arguments.silent ? "yes" : "no");
169 }
170
171 exit (0);
172}
Definition: argp.h:213
Definition: ex3.c:83