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   1 /* uprf.c - "unsigned" lexical prefix  */
   2 #ifndef lint
   3 static char ident[] = "@(#)$Id: uprf.c,v 1.8 1992/12/15 00:20:22 jromine Exp $";
   4 #endif  /* lint */
   5
   6 #define TO_LOWER 040
   7 #define NO_MASK  000
   8 #include <ctype.h>
   9
  10 uprf (c1, c2)
  11 register char  *c1,
  12                *c2;
  13 {
  14     register int    c,
  15                     mask;
  16
  17     if (c1 == 0 || c2 == 0)
  18         return(0);         /* XXX */
  19
  20     while (c = *c2++)
  21     {
  22 #ifdef LOCALE
  23         c &= 0xff;
  24         mask = *c1 & 0xff;
  25         c = (isalpha(c) && isupper(c)) ? tolower(c) : c;
  26         mask = (isalpha(mask) && isupper(mask)) ? tolower(mask) : mask;
  27         if (c != mask)
  28 #else
  29         mask = (isalpha(c) && isalpha(*c1)) ?  TO_LOWER : NO_MASK;
  30         if ((c | mask) != (*c1 | mask))
  31 #endif
  32             return 0;
  33         else
  34             c1++;
  35     }
  36     return 1;
  37 }