flower/libc-extension.cc

   1 /*
   2   libc-extension.cc --  compensate for lacking libc functions.
   3
   4
   5   source file of the flowerlib
   6
   7   (c) 1997 Han-Wen Nienhuys <hanwen@stack.nl>
   8 */
   9 #include <stdarg.h>
  10 #include <string.h>
  11 #include <ctype.h>
  12 #include "libc-extension.hh"
  13
  14
  15 char*
  16 strnlwr( char* start_l ,int n)
  17 {
  18     char * p = start_l + n;
  19     while ( --p >= start_l) {
  20         *p = tolower( *p );    /* a macro on some compilers */
  21     }
  22     return start_l;
  23 }
  24
  25 char*
  26 strnupr( char* start_l, int n)
  27 {
  28     char * p = start_l + n;
  29     while ( --p >= start_l) {
  30         *p = toupper( *p );    /* a macro on some compilers */
  31     }
  32     return start_l;
  33 }
  34
  35 #if !HAVE_MEMMEM
  36
  37 /** locate a substring. #memmem# finds the first occurrence of
  38   #needle# in #haystack#
  39   */
  40
  41 char *
  42 memmem(Byte const * haystack, int haystack_len,
  43        Byte const *needle,int needle_len)
  44 {
  45     Byte const * end_haystack = haystack + haystack_len - needle_len;
  46     Byte const * end_needle = needle + needle_len ;
  47
  48     /* Ahhh ... Some minimal lowlevel stuff. This *is* nice; Varation
  49       is the spice of life */
  50     while (haystack < end_haystack) {
  51         Byte const *subneedle_l = needle;
  52         Byte const *subhaystack_l = haystack;
  53         while (subneedle_l < end_needle) {
  54             if (*subneedle_l++ != *subhaystack_l++)
  55                 goto next;      // yeah. I should be prosecuted.
  56         }
  57
  58         // completed the needle. Gotcha.
  59         return (char*) haystack;
  60     next:
  61         haystack++;
  62     }
  63     return 0;
  64 }
  65 #endif
  66
  67 Byte *
  68 memrchr(Byte const * p, int n, char c)
  69 {
  70     const    Byte * q = p+n;
  71     while (q > p) {
  72         if (*--q == c)
  73             return (Byte*)q;
  74     }
  75     return 0;
  76 }
  77
  78
  79 template<class T>
  80 inline void
  81 my_swap(T &t1, T &t2, T &tmp)
  82 {
  83     tmp = t1;
  84     t1 = t2;
  85     t2 = tmp;
  86 }
  87
  88 Byte*
  89 strrev( Byte* byte_l, int length_i )
  90 {
  91   Byte tmp_byte;
  92
  93   Byte* left_l = byte_l;
  94   Byte* right_l = byte_l + length_i;
  95
  96   while ( right_l > left_l ) {
  97       my_swap(*right_l-- , *left_l++ , tmp_byte);
  98   }
  99   return byte_l;
 100 }
 101
 102 #if ! HAVE_SNPRINTF
 103 int snprintf ( char *str, size_t,
 104                char const *format, ... )
 105 {
 106     va_list ap;
 107     va_start(ap, format);
 108     int i = vsprintf(str, format, ap);
 109     va_end(ap);
 110     return i;
 111 }
 112 #endif