The program shown below scans from a string and prints a value
stored in a variable of an integer type that doesn't have a
length modifier. The appropriate conversions from and to
intmax_t, and the appropriate range checks, are used as explained
in the notes section above.
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <sys/types.h>
int
main (void)
{
static const char *const str = "500000 us in half a second";
suseconds_t us;
intmax_t tmp;
/* Scan the number from the string into the temporary variable. */
sscanf(str, "%jd", &tmp);
/* Check that the value is within the valid range of suseconds_t. */
if (tmp < -1 || tmp > 1000000) {
fprintf(stderr, "Scanned value outside valid range!\n");
exit(EXIT_FAILURE);
}
/* Copy the value to the suseconds_t variable 'us'. */
us = tmp;
/* Even though suseconds_t can hold the value -1, this isn't
a sensible number of microseconds. */
if (us < 0) {
fprintf(stderr, "Scanned value shouldn't be negative!\n");
exit(EXIT_FAILURE);
}
/* Print the value. */
printf("There are %jd microseconds in half a second.\n",
(intmax_t) us);
exit(EXIT_SUCCESS);
}
