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  int ifd = 0, ofd, idx = 0, m = m;
  30  char *line = 0, mode[16],
  31       *class[] = {"begin%*[ ]%15s%*[ ]%n", "begin-base64%*[ ]%15s%*[ ]%n"};
  32
  33  if (toys.optc) ifd = xopenro(*toys.optargs);
  34
  35  while (!idx) {
  36    free(line);
  37    if (!(line = get_line(ifd))) error_exit("bad EOF");
  38    for (m=0; m < 2; m++) {
  39      sscanf(line, class[m], mode, &idx);
  40      if (idx) break;
  41    }
  42  }
  43
  44  if (TT.o && !strcmp(TT.o, "-")) ofd = 1;
  45  else ofd = xcreate(TT.o ? TT.o : line+idx, O_WRONLY|O_CREAT|O_TRUNC,
  46    string_to_mode(mode, 0777^toys.old_umask));
  47
  48  for(;;) {
  49    char *in, *out;
  50    int olen;
  51
  52    free(line);
  53    if (m == 2 || !(line = get_line(ifd))) break;
  54    if (!strcmp(line, m ? "====" : "end")) {
  55      m = 2;
  56      continue;
  57    }
  58
  59    olen = 0;
  60    in = out = line;
  61    if (!m) olen = (*(in++) - 32) & 0x3f;
  62
  63    for (;;) {
  64      int i = 0, x = 0, len = 4;
  65      char c = 0;
  66
  67      if (!m) {
  68        if (olen < 1) break;
  69        if (olen < 3) len = olen + 1;
  70      }
  71
  72      while (i < len) {
  73        if (!(c = *(in++))) goto line_done;
  74
  75        if (m) {
  76          if (c == '=') {
  77            len--;
  78            continue;
  79          } else if (len != 4) break;
  80
  81          if (c >= 'A' && c <= 'Z') c -= 'A';
  82          else if (c >= 'a' && c <= 'z') c += 26 - 'a';
  83          else if (c >= '0' && c <= '9') c += 52 - '0';
  84          else if (c == '+') c = 62;
  85          else if (c == '/') c = 63;
  86          else continue;
  87        } else c = (c - 32) & 0x3f;
  88
  89        x |= c << (6*(3-i));
  90
  91        if (i && i < len) {
  92          *(out++) = (x>>(8*(3-i))) & 0xff;
  93          olen--;
  94        }
  95        i++;
  96      }
  97
  98      if (i && i!=len) error_exit("bad %s", line);
  99    }
 100line_done:
 101    xwrite(ofd, line, out-line);
 102  }
 103
 104  if (CFG_TOYBOX_FREE) {
 105    if (ifd) close(ifd);
 106    close(ofd);
 107  }
 108}
 109