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

   1
   2 /*
   3  * uprf.c -- "unsigned" lexical prefix
   4  *
   5  * This code is Copyright (c) 2002, by the authors of nmh.  See the
   6  * COPYRIGHT file in the root directory of the nmh distribution for
   7  * complete copyright information.
   8  */
   9
  10 #include <h/mh.h>
  11
  12
  13 /* uprf returns true if s starts with prefix, ignoring case.
  14  * Otherwise false.  If s or prefix are NULL then false results. */
  15 int
  16 uprf(const char *s, const char *prefix)
  17 {
  18     unsigned char *us, *up;
  19
  20     if (!s || !prefix)
  21         return 0;
  22     us = (unsigned char *)s;
  23     up = (unsigned char *)prefix;
  24
  25     while (*us && tolower(*us) == tolower(*up)) {
  26         us++;
  27         up++;
  28     }
  29
  30     return *up == '\0';
  31 }