source: buchla-68k/libsm/strrev.c@ 7258c6a

/*
   =============================================================================
        strrev.c -- reverse a string
        Version 1 -- 1988-02-03 -- D.N. Lynx Crowe

        char *
        strrev(s1, s2)
        char *s1;
        char *s2;

                Copies string 's2' into 's1'.  's1' must be large enough
                to hold 's2'.  Returns 's1'.
   =============================================================================
*/

int8_t *strrev(int8_t *s1, int8_t *s2)
{
        register int8_t *s3;
        register int32_t i;

        i = 0L;                         /* initialize string length */
        s3 = s1;                        /* initialize target left end pointer */

        while (*s2) {                   /* find right end of source string */

                ++s2;
                ++i;
        }

        --s2;                           /* adjust source right end pointer */

        while (i--)                     /* copy string in reverse */
                *s3++ = *s2--;

        *s3 = '\0';                     /* terminate the string */
        return(s1);                     /* return address of reversed string */
}