pith/osdep/collate.c

   1 /*
   2  * ========================================================================
   3  * Copyright 2013-2022 Eduardo Chappa
   4  * Copyright 2006 University of Washington
   5  *
   6  * Licensed under the Apache License, Version 2.0 (the "License");
   7  * you may not use this file except in compliance with the License.
   8  * You may obtain a copy of the License at
   9  *
  10  *     http://www.apache.org/licenses/LICENSE-2.0
  11  *
  12  * ========================================================================
  13  */
  14
  15 #include <system.h>
  16
  17 #include "collate.h"
  18
  19
  20 /*
  21  * global hook
  22  */
  23 int (*pcollator)(const char *, const char *);
  24
  25
  26 void
  27 set_collation(int collation, int ctype)
  28 {
  29     extern int collator(const char *, const char *);  /* set to strcoll if available in system.h */
  30
  31     pcollator = strucmp;
  32
  33 #ifdef LC_COLLATE
  34   if(collation){
  35       char *status = NULL;
  36
  37     /*
  38      * This may not have the desired effect, if collator is not
  39      * defined to be strcoll in os.h and strcmp and friends
  40      * don't know about locales. If your system does have strcoll
  41      * but we haven't defined collator to be strcoll in os.h, let us know.
  42      */
  43     status = setlocale(LC_COLLATE, "");
  44
  45     /*
  46      * If there is an error or if the locale is the "C" locale, then we
  47      * don't want to use strcoll because in the default "C" locale strcoll
  48      * uses strcmp ordering and we want strucmp ordering.
  49      *
  50      * The problem with this is that setlocale returns a string which is
  51      * not equal to "C" on some systems even when the locale is "C", so we
  52      * can't really tell on those systems. On some systems like that, we
  53      * may end up with a strcmp-style collation instead of a strucmp-style.
  54      * We recommend that the users of those systems explicitly set
  55      * LC_COLLATE in their environment.
  56      */
  57     if(status && !(status[0] == 'C' && status[1] == '\0'))
  58       pcollator = collator;
  59   }
  60 #endif
  61 #ifdef LC_CTYPE
  62   if(ctype){
  63     (void)setlocale(LC_CTYPE, "");
  64   }
  65 #endif
  66
  67 #ifdef LC_TIME
  68   setlocale(LC_TIME, "");
  69 #endif
  70 }
  71
  72
  73 /*
  74  * sstrcasecmp - compare two pointers to strings case independently
  75  */
  76 int
  77 sstrcasecmp(const qsort_t *s1, const qsort_t *s2)
  78 {
  79     return((*pcollator)(*(char **)s1, *(char **)s2));
  80 }
  81
  82
  83 #ifndef _WINDOWS
  84
  85 /*--------------------------------------------------
  86      A case insensitive strcmp()
  87
  88    Args: o, r -- The two strings to compare
  89
  90  Result: integer indicating which is greater
  91   ---*/
  92 int
  93 strucmp(const char *o, const char *r)
  94 {
  95     if(o == NULL){
  96         if(r == NULL)
  97           return 0;
  98         else
  99           return -1;
 100     }
 101     else if(r == NULL)
 102       return 1;
 103
 104     while(*o && *r
 105           && ((isupper((unsigned char)(*o))
 106                                   ? (unsigned char)tolower((unsigned char)(*o))
 107                                   : (unsigned char)(*o))
 108              == (isupper((unsigned char)(*r))
 109                                   ? (unsigned char)tolower((unsigned char)(*r))
 110                                   : (unsigned char)(*r)))){
 111         o++;
 112         r++;
 113     }
 114
 115     return((isupper((unsigned char)(*o))
 116                                 ? tolower((unsigned char)(*o))
 117                                 : (int)(unsigned char)(*o))
 118            - (isupper((unsigned char)(*r))
 119                                 ? tolower((unsigned char)(*r))
 120                                 : (int)(unsigned char)(*r)));
 121 }
 122
 123 /*----------------------------------------------------------------------
 124      A case insensitive strncmp()
 125
 126    Args: o, r -- The two strings to compare
 127          n    -- length to stop comparing strings at
 128
 129  Result: integer indicating which is greater
 130
 131   ----*/
 132 int
 133 struncmp(const char *o, const char *r, int n)
 134 {
 135     if(n < 1)
 136       return 0;
 137
 138     if(o == NULL){
 139         if(r == NULL)
 140           return 0;
 141         else
 142           return -1;
 143     }
 144     else if(r == NULL)
 145       return 1;
 146
 147     n--;
 148     while(n && *o && *r
 149           && ((isupper((unsigned char)(*o))
 150                                   ? (unsigned char)tolower((unsigned char)(*o))
 151                                   : (unsigned char)(*o))
 152              == (isupper((unsigned char)(*r))
 153                                   ? (unsigned char)tolower((unsigned char)(*r))
 154                                   : (unsigned char)(*r)))){
 155         o++;
 156         r++;
 157         n--;
 158     }
 159
 160     return((isupper((unsigned char)(*o))
 161                                 ? tolower((unsigned char)(*o))
 162                                 : (int)(unsigned char)(*o))
 163            - (isupper((unsigned char)(*r))
 164                                 ? tolower((unsigned char)(*r))
 165                                 : (int)(unsigned char)(*r)));
 166 }
 167 #endif