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 
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>";
34 
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.";
42 
43 /* A description of the arguments we accept. */
44 static 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. */
50 static 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'. */
66 struct 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. */
76 static error_t
77 parse_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. */
132 static struct argp argp = { options, parse_opt, args_doc, doc, 0, 0, 0};
133 
134 int 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 }
argp
Definition: argp.h:212
arguments
Definition: ex3.c:82
argp_state
Definition: argp.h:302
argp_option
Definition: argp.h:73