sys/src/cmd/urlencode.c

   1 #include <u.h>
   2 #include <libc.h>
   3 #include <bio.h>
   4
   5 Biobuf  bin;
   6 Biobuf  bout;
   7 int     dflag;
   8
   9 char    hex[] = "0123456789abcdef";
  10 char    Hex[] = "0123456789ABCDEF";
  11
  12 int
  13 hexdigit(int c)
  14 {
  15         char *p;
  16
  17         if(c > 0){
  18                 if((p = strchr(Hex, c)) != 0)
  19                         return p - Hex;
  20                 if((p = strchr(hex, c)) != 0)
  21                         return p - hex;
  22         }
  23         return -1;
  24 }
  25
  26 void
  27 usage(void)
  28 {
  29         fprint(2, "Usage: %s [ -d ] [ file ]\n", argv0);
  30         exits("usage");
  31 }
  32
  33 void
  34 main(int argc, char *argv[])
  35 {
  36         int c;
  37
  38         ARGBEGIN {
  39         case 'd':
  40                 dflag = 1;
  41                 break;
  42         default:
  43                 usage();
  44         } ARGEND;
  45
  46         if(argc == 1){
  47                 int fd;
  48
  49                 fd = open(*argv, OREAD);
  50                 if(fd < 0)
  51                         sysfatal("%r");
  52                 if(fd != 0) dup(fd, 0);
  53         } else if(argc > 1)
  54                 usage();
  55
  56         Binit(&bin, 0, OREAD);
  57         Binit(&bout, 1, OWRITE);
  58
  59         if(dflag){
  60                 while((c = Bgetc(&bin)) >= 0){
  61                         if(c == '%'){
  62                                 int c1, c2, x1, x2;
  63
  64                                 if((c1 = Bgetc(&bin)) < 0)
  65                                         break;
  66                                 if((x1 = hexdigit(c1)) < 0){
  67                                         Bungetc(&bin);
  68                                         Bputc(&bout, c);
  69                                         continue;
  70                                 }
  71                                 if((c2 = Bgetc(&bin)) < 0)
  72                                         break;
  73                                 if((x2 = hexdigit(c2)) < 0){
  74                                         Bungetc(&bin);
  75                                         Bputc(&bout, c);
  76                                         Bputc(&bout, c1);
  77                                         continue;
  78                                 }
  79                                 c = x1<<4 | x2;
  80                         } else if(c == '+')
  81                                 c = ' ';
  82                         Bputc(&bout, c);
  83                 }
  84         } else {
  85                 while((c = Bgetc(&bin)) >= 0){
  86                         if(c>0 && strchr("/$-_@.!*'(),", c)
  87                         || 'a'<=c && c<='z'
  88                         || 'A'<=c && c<='Z'
  89                         || '0'<=c && c<='9')
  90                                 Bputc(&bout, c);
  91                         else if(c == ' ')
  92                                 Bputc(&bout, '+');
  93                         else {
  94                                 Bputc(&bout, '%');
  95                                 Bputc(&bout, Hex[c>>4]);
  96                                 Bputc(&bout, Hex[c&15]);
  97                         }
  98                 }
  99         }
 100
 101         Bflush(&bout);
 102         exits(0);
 103 }