Attached is a minimal test case showing the problem.
Compile with "gcc -o minargp minargp.c",
run with somthing like "./minargp -r 15"
to get
argument value for -r = (null)
repeat count has been set to 10
Expected behaviour:
argument value for -r = 15
repeat count has been set to 15
Why is the argument value empty?
Drew
#include <stdlib.h>
#include <argp.h>
/* Program documentation. */
static char doc[] =
"minimal argp test for OPTION_ARG_OPTIONAL.";
/* A description of the arguments we accept. */
static char args_doc[] = "";
/* The options we understand. */
static struct argp_option options[] = {
{"repeat", 'r', "COUNT", OPTION_ARG_OPTIONAL,
"Repeat the output COUNT (default 10) times"},
{ 0 }
};
/* Used by `main' to communicate with `parse_opt'. */
struct arguments
{
int repeat_count; /* COUNT arg to `--repeat' */
};
/* Parse a single option. */
static error_t
parse_opt (int key, char *arg, struct argp_state *state)
{
/* Get the `input' argument from `argp_parse', which we
know is a pointer to our arguments structure. */
struct arguments *arguments = state->input;
switch (key)
{
case 'r':
printf("argument value for -r = %s\n", arg);
arguments->repeat_count = arg ? atoi (arg) : 10;
break;
}
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.repeat_count = 1;
argp_parse (&argp, argc, argv, 0, 0, &arguments);
printf("repeat count has been set to %i\n", arguments.repeat_count );
}
