flower/lib/libc-extension.cc

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