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
  10
  11 /* uprf returns true if s starts with prefix, ignoring case.
  12  * Otherwise false.  If s or prefix are NULL then false results. */
  13 int
  14 uprf(const char *s, const char *prefix)
  15 {
  16     unsigned char *us, *up;
  17
  18     if (!s || !prefix)
  19         return 0;
  20     us = (unsigned char *)s;
  21     up = (unsigned char *)prefix;
  22
  23     while (*us && tolower(*us) == tolower(*up)) {
  24         us++;
  25         up++;
  26     }
  27
  28     return *up == '\0';
  29 }