diplodocus.org Git - nmh/blob - sbr/uprf.c

   1 /* uprf.c -- "unsigned" lexical prefix
   2  *
   3  * This code is Copyright (c) 2002, by the authors of nmh.  See the
   4  * COPYRIGHT file in the root directory of the nmh distribution for
   5  * complete copyright information.
   6  */
   7
   8 #include "h/mh.h"
   9 #include "uprf.h"
  10
  11
  12 /* uprf returns true if s starts with prefix, ignoring case.
  13  * Otherwise false.  If s or prefix are NULL then false results. */
  14 int
  15 uprf(const char *s, const char *prefix)
  16 {
  17     unsigned char *us, *up;
  18
  19     if (!s || !prefix)
  20         return 0;
  21     us = (unsigned char *)s;
  22     up = (unsigned char *)prefix;
  23
  24     while (*us && tolower(*us) == tolower(*up)) {
  25         us++;
  26         up++;
  27     }
  28
  29     return *up == '\0';
  30 }