rc_config.3 (manual page) has erroneous description for rc_yesno()

[gkloepfer]

The current description for rc_yesno() in rc_config.3 manual page has an ambiguous or somewhat nonsense description. As currently described, rc_yesno will not return if value is not true, and will set EINVAL if "value" is not a false description. It also indicates it recognizes "on" as a possible value, and it does not.

This is not how rc_yesno() actually works.

The description should be changed as follows:

**** returns true if value is true, yes, y, or 1 (regardless of case), otherwise returns false. If value is not a valid representation of true or the values false, no, n, or 0 (regardless of case), then rc_yesno() returns false and errno is set to EINVAL.

Here is the output of test cases for rc_yesno() that should exemplify what the manual page should describe:

$ ./docbug
Test case [yes] ==> returns [true] / errno 0
Test case [YES] ==> returns [true] / errno 0
Test case [Yes] ==> returns [true] / errno 0
Test case [Y] ==> returns [true] / errno 0
Test case [Yup] ==> returns [false] / errno 22
Test case [1] ==> returns [true] / errno 0
Test case [true] ==> returns [true] / errno 0
Test case [TRUE] ==> returns [true] / errno 0
Test case [True] ==> returns [true] / errno 0
Test case [One] ==> returns [false] / errno 22
Test case [on] ==> returns [false] / errno 22
Test case [On] ==> returns [false] / errno 22
Test case [oN] ==> returns [false] / errno 22
Test case [no] ==> returns [false] / errno 0
Test case [NO] ==> returns [false] / errno 0
Test case [No] ==> returns [false] / errno 0
Test case [N] ==> returns [false] / errno 0
Test case [Nope] ==> returns [false] / errno 22
Test case [0] ==> returns [false] / errno 0
Test case [false] ==> returns [false] / errno 0
Test case [FALSE] ==> returns [false] / errno 0
Test case [False] ==> returns [false] / errno 0
Test case [off] ==> returns [false] / errno 22
Test case [This] ==> returns [false] / errno 22
Test case [Is] ==> returns [false] / errno 22
Test case [just] ==> returns [false] / errno 22
Test case [some] ==> returns [false] / errno 22
Test case [random] ==> returns [false] / errno 22
Test case [Junk] ==> returns [false] / errno 22

If it is desired to recognize on/off as values, then this is a bug in rc_yesno().

The following is the program that generates the output above:

#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
#include <errno.h>

#include <rc.h>

int main(int argc, char *argv[])
{
        char *test_cases[] = {
                "yes", "YES", "Yes", "Y", "Yup", "1", "true", "TRUE", "True",
                "One", "on", "On", "oN",

                "no", "NO", "No", "N", "Nope", "0", "false", "FALSE", "False",
                "off",

                "This", "Is", "just", "some", "random", "Junk",
                NULL
        };

        int i;
        bool ret;

        for (i = 0; test_cases[i] != NULL; i++) {
                errno = 0;
                ret = rc_yesno(test_cases[i]);
                printf("Test case [%s] ==> returns [%s] / errno %d\n",
                        test_cases[i], (ret ? "true" : "false"), errno);
        }

        exit(0);
}