sys/src/libregexp/rregsub.c

   1 #include <u.h>
   2 #include <libc.h>
   3 #include <regexp.h>
   4
   5 void
   6 rregsub(Rune *src, Rune *dst, int dlen, Resub *match, int msize)
   7 {
   8         int i;
   9         Rune *ep, r;
  10
  11         ep = dst + dlen-1;
  12         for(;*src != L'\0'; src++) switch(*src) {
  13         case L'\\':
  14                 switch(*++src) {
  15                 case L'0':
  16                 case L'1':
  17                 case L'2':
  18                 case L'3':
  19                 case L'4':
  20                 case L'5':
  21                 case L'6':
  22                 case L'7':
  23                 case L'8':
  24                 case L'9':
  25                         i = *src - L'0';
  26                         if(match != nil && i < msize && match[i].rsp != nil) {
  27                                 r = *match[i].rep;
  28                                 *match[i].rep = L'\0';
  29                                 dst = runestrecpy(dst, ep+1, match[i].rsp);
  30                                 *match[i].rep = r;
  31                         }
  32                         break;
  33                 case L'\\':
  34                         if(dst < ep)
  35                                 *dst++ = L'\\';
  36                         else
  37                                 goto End;
  38                         break;
  39                 case L'\0':
  40                         goto End;
  41                 default:
  42                         if(dst < ep)
  43                                 *dst++ = *src;
  44                         else
  45                                 goto End;
  46                         break;
  47                 }
  48                 break;
  49         case L'&':
  50                 if(match != nil && msize > 0 && match[0].rsp != nil) {
  51                         r = *match[0].rep;
  52                         *match[0].rep = L'\0';
  53                         dst = runestrecpy(dst, ep+1, match[0].rsp);
  54                         *match[0].rep = r;
  55                 }
  56                 break;
  57         default:
  58                 if(dst < ep)
  59                         *dst++ = *src;
  60                 else
  61                         goto End;
  62                 break;
  63         }
  64 End:
  65         *dst = L'\0';
  66 }