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Diffstat (limited to 'manual/examples/argp-ex4.c')
| -rw-r--r-- | manual/examples/argp-ex4.c | 144 |
1 files changed, 144 insertions, 0 deletions
diff --git a/manual/examples/argp-ex4.c b/manual/examples/argp-ex4.c new file mode 100644 index 0000000000..24dd417a81 --- /dev/null +++ b/manual/examples/argp-ex4.c @@ -0,0 +1,144 @@ +/* Argp example #4 -- a program with somewhat more complicated options */ + +#include <stdlib.h> +#include <error.h> +#include <argp.h> + +const char *argp_program_version = + "argp-ex4 1.0"; +const char *argp_program_bug_address = + "<bug-gnu-utils@@prep.ai.mit.edu>"; + +/* Program documentation. */ +static char doc[] = + "Argp example #4 -- a program with somewhat more complicated\ +options\ +\vThis part of the documentation comes *after* the options;\ + note that the text is automatically filled, but it's possible\ + to force a line-break, e.g.\n<-- here."; + +/* A description of the arguments we accept. */ +static char args_doc[] = "ARG1 [STRING...]"; + +/* Keys for options without short-options. */ +#define OPT_ABORT 1 /* --abort */ + +/* The options we understand. */ +static struct argp_option options[] = { + {"verbose", 'v', 0, 0, "Produce verbose output" }, + {"quiet", 'q', 0, 0, "Don't produce any output" }, + {"silent", 's', 0, OPTION_ALIAS }, + {"output", 'o', "FILE", 0, + "Output to FILE instead of standard output" }, + + {0,0,0,0, "The following options should be grouped together:" }, + {"repeat", 'r', "COUNT", OPTION_ARG_OPTIONAL, + "Repeat the output COUNT (default 10) times"}, + {"abort", OPT_ABORT, 0, 0, "Abort before showing any output"}, + + { 0 } +}; + +/* Used by @code{main} to communicate with @code{parse_opt}. */ +struct arguments +{ + char *arg1; /* @var{arg1} */ + char **strings; /* [@var{string}@dots{}] */ + int silent, verbose, abort; /* @samp{-s}, @samp{-v}, @samp{--abort} */ + char *output_file; /* @var{file} arg to @samp{--output} */ + int repeat_count; /* @var{count} arg to @samp{--repeat} */ +}; + +/* Parse a single option. */ +static error_t +parse_opt (int key, char *arg, struct argp_state *state) +{ + /* Get the @code{input} argument from @code{argp_parse}, which we + know is a pointer to our arguments structure. */ + struct arguments *arguments = state->input; + + switch (key) + { + case 'q': case 's': + arguments->silent = 1; + break; + case 'v': + arguments->verbose = 1; + break; + case 'o': + arguments->output_file = arg; + break; + case 'r': + arguments->repeat_count = arg ? atoi (arg) : 10; + break; + case OPT_ABORT: + arguments->abort = 1; + break; + + case ARGP_KEY_NO_ARGS: + argp_usage (state); + + case ARGP_KEY_ARG: + /* Here we know that @code{state->arg_num == 0}, since we + force argument parsing to end before any more arguments can + get here. */ + arguments->arg1 = arg; + + /* Now we consume all the rest of the arguments. + @code{state->next} is the index in @code{state->argv} of the + next argument to be parsed, which is the first @var{string} + we're interested in, so we can just use + @code{&state->argv[state->next]} as the value for + arguments->strings. + + @emph{In addition}, by setting @code{state->next} to the end + of the arguments, we can force argp to stop parsing here and + return. */ + arguments->strings = &state->argv[state->next]; + state->next = state->argc; + + break; + + default: + return ARGP_ERR_UNKNOWN; + } + return 0; +} + +/* Our argp parser. */ +static struct argp argp = { options, parse_opt, args_doc, doc }; + +int main (int argc, char **argv) +{ + int i, j; + struct arguments arguments; + + /* Default values. */ + arguments.silent = 0; + arguments.verbose = 0; + arguments.output_file = "-"; + arguments.repeat_count = 1; + arguments.abort = 0; + + /* Parse our arguments; every option seen by @code{parse_opt} will be + reflected in @code{arguments}. */ + argp_parse (&argp, argc, argv, 0, 0, &arguments); + + if (arguments.abort) + error (10, 0, "ABORTED"); + + for (i = 0; i < arguments.repeat_count; i++) + { + printf ("ARG1 = %s\n", arguments.arg1); + printf ("STRINGS = "); + for (j = 0; arguments.strings[j]; j++) + printf (j == 0 ? "%s" : ", %s", arguments.strings[j]); + printf ("\n"); + printf ("OUTPUT_FILE = %s\nVERBOSE = %s\nSILENT = %s\n", + arguments.output_file, + arguments.verbose ? "yes" : "no", + arguments.silent ? "yes" : "no"); + } + + exit (0); +} |