LXR toybox/toys/posix/uudecode.c

   1/* uudecode.c - uudecode / base64 decode
   2 *
   3 * Copyright 2013 Erich Plondke <toybox@erich.wreck.org>
   4 *
   5 * See http://pubs.opengroup.org/onlinepubs/9699919799/utilities/uudecode.html
   6
   7USE_UUDECODE(NEWTOY(uudecode, ">1o:", TOYFLAG_USR|TOYFLAG_BIN|TOYFLAG_UMASK))
   8
   9config UUDECODE
  10  bool "uudecode"
  11  default y
  12  help
  13    usage: uudecode [-o OUTFILE] [INFILE]
  14
  15    Decode file from stdin (or INFILE).
  16
  17    -o  Write to OUTFILE instead of filename in header
  18*/
  19
  20#define FOR_uudecode
  21#include "toys.h"
  22
  23GLOBALS(
  24  char *o;
  25)
  26
  27void uudecode_main(void)
  28{
  29  FILE *ifp = stdin;
  30  int ofd, idx = 0, m QUIET, n;
  31  size_t allocated_length;
  32  char *line = 0, mode[16],
  33       *class[] = {"begin%*[ ]%15s%*[ ]%n", "begin-base64%*[ ]%15s%*[ ]%n"};
  34
  35  if (toys.optc) ifp = xfopen(*toys.optargs, "r");
  36
  37  while (!idx) {
  38    if ((n = getline(&line, &allocated_length, ifp)) == -1)
  39      error_exit("no begin line");
  40    if (!n) continue;
  41    line[n-1] = 0;
  42    for (m=0; m < 2; m++) {
  43      sscanf(line, class[m], mode, &idx);
  44      if (idx) break;
  45    }
  46  }
  47
  48  if (TT.o && !strcmp(TT.o, "-")) ofd = 1;
  49  else ofd = xcreate(TT.o ? TT.o : line+idx, O_WRONLY|O_CREAT|O_TRUNC,
  50    string_to_mode(mode, 0777^toys.old_umask));
  51
  52  for (;;) {
  53    char *in, *out;
  54    int olen;
  55
  56    if (m == 2 || (n = getline(&line, &allocated_length, ifp)) == -1) break;
  57    if (n) line[n-1] = 0;
  58    if (!strcmp(line, m ? "====" : "end")) {
  59      m = 2;
  60      continue;
  61    }
  62
  63    olen = 0;
  64    in = out = line;
  65    if (!m) olen = (*(in++) - 32) & 0x3f;
  66
  67    for (;;) {
  68      int i = 0, x = 0, len = 4;
  69      char c = 0;
  70
  71      if (!m) {
  72        if (olen < 1) break;
  73        if (olen < 3) len = olen + 1;
  74      }
  75
  76      while (i < len) {
  77        if (!(c = *(in++))) goto line_done;
  78
  79        if (m) {
  80          if (c == '=') {
  81            len--;
  82            continue;
  83          } else if (len != 4) break;
  84
  85          if (c >= 'A' && c <= 'Z') c -= 'A';
  86          else if (c >= 'a' && c <= 'z') c += 26 - 'a';
  87          else if (c >= '0' && c <= '9') c += 52 - '0';
  88          else if (c == '+') c = 62;
  89          else if (c == '/') c = 63;
  90          else continue;
  91        } else c = (c - 32) & 0x3f;
  92
  93        x |= c << (6*(3-i));
  94
  95        if (i && i < len) {
  96          *(out++) = (x>>(8*(3-i))) & 0xff;
  97          olen--;
  98        }
  99        i++;
 100      }
 101
 102      if (i && i!=len) error_exit("bad %s", line);
 103    }
 104line_done:
 105    xwrite(ofd, line, out-line);
 106  }
 107
 108  if (CFG_TOYBOX_FREE) {
 109    if (ifp != stdin) fclose(ifp);
 110    close(ofd);
 111    free(line);
 112  }
 113}
 114