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--1999 Han-Wen Nienhuys <hanwen@cs.uu.nl>
   8          Jan Nieuwenhuizen <janneke@gnu.org>
   9 */
  10
  11 #include <stdio.h>
  12 #include <string.h>
  13 #include <ctype.h>
  14 #include "libc-extension.hh"
  15
  16 /*
  17   urg: why soo wierd?
  18  */
  19 char*
  20 strnlwr (char* start_l ,int n)
  21 {
  22   char * p = start_l + n;
  23   while (--p >= start_l)
  24     {
  25       *p = tolower (*p);    /* a macro on some compilers */
  26     }
  27   return start_l;
  28 }
  29
  30 char*
  31 strnupr (char* start_l, int n)
  32 {
  33   char * p = start_l + n;
  34   while (--p >= start_l)
  35     {
  36       *p = toupper (*p);    /* a macro on some compilers */
  37     }
  38   return start_l;
  39 }
  40
  41
  42 #if !HAVE_MEMMEM
  43
  44 /** locate a substring. #memmem# finds the first occurrence of
  45   #needle# in #haystack#.  This is not ANSI-C.
  46
  47   The prototype is not in accordance with the Linux Programmer's
  48   Manual v1.15, but it is with /usr/include/string.h   */
  49
  50 Byte *
  51 memmem (Byte const *haystack, int haystack_len,
  52         Byte const *needle,int needle_len)
  53 {
  54   Byte const * end_haystack = haystack + haystack_len - needle_len + 1;
  55   Byte const * end_needle = needle + needle_len ;
  56
  57   /* Ahhh ... Some minimal lowlevel stuff. This *is* nice; Varation
  58      is the spice of life */
  59   while (haystack < end_haystack)
  60     {
  61       Byte const *subneedle_l = needle;
  62       Byte const *subhaystack_l = haystack;
  63       while (subneedle_l < end_needle)
  64         if (*subneedle_l++ != *subhaystack_l++)
  65           goto next;
  66
  67       // completed the needle. Gotcha.
  68       return (Byte *) haystack;
  69       next:
  70         haystack++;
  71     }
  72   return 0;
  73 }
  74
  75 #endif
  76
  77 Byte *
  78 memrchr (Byte const * p, int n, char c)
  79 {
  80   const    Byte * q = p+n;
  81   while (q > p)
  82     {
  83       if (*--q == c)
  84         return (Byte*)q;
  85     }
  86   return 0;
  87 }
  88
  89
  90 template<class T>
  91 inline void
  92 my_swap (T &t1, T &t2, T &tmp)
  93 {
  94   tmp = t1;
  95   t1 = t2;
  96   t2 = tmp;
  97 }
  98
  99 Byte*
 100 strrev (Byte* byte_l, int length_i)
 101 {
 102   Byte tmp_byte;
 103
 104   Byte* left_l = byte_l;
 105   Byte* right_l = byte_l + length_i;
 106
 107   while (right_l > left_l)
 108     {
 109       my_swap (*right_l-- , *left_l++ , tmp_byte);
 110     }
 111   return byte_l;
 112 }
 113
 114 #if ! HAVE_SNPRINTF
 115 int
 116 snprintf (char *str, size_t, char const *format, ...)
 117 {
 118   va_list ap;
 119   va_start (ap, format);
 120   int i = vsprintf (str, format, ap);
 121   va_end (ap);
 122   return i;
 123 }
 124 #endif
 125
 126 #if ! HAVE_VSNPRINTF
 127 int
 128 vsnprintf (char *str, size_t, char const *format, va_list args)
 129 {
 130   int i = vsprintf (str, format, args);
 131   return i;
 132 }
 133 #endif
 134