strrchr.c

Many C samples. It is a good sample for students to learn C language.

/*  File   : strrchr.c
    Author : Richard A. O'Keefe.
    Updated: 10 April 1984
    Defines: strrchr(), rindex()

    strrchr(s, c) returns a pointer to the  last  place  in  s  where  c
    occurs,  or  NullS if c does not occur in s. This function is called
    rindex in V7 and 4.?bsd systems; while not ideal the name is clearer
    than strrchr, so rindex  remains  in  strings.h  as  a  macro.   NB:
    strrchr  looks  for single characters, not for sets or strings.  The
    parameter 'c' is declared 'int' so it will go in a register; if your
    C compiler is happy with register char change it to that.
*/

#include "strings.h"

char *strrchr(s, c)
    register _char_ *s;
    register int c;
    {
	register char *t;

	t = NullS;
	do if (*s == c) t = s; while (*s++);
	return t;
    }