LXR toybox/toys/other/base64.c

   1/* base64.c - Encode and decode base64
   2 *
   3 * Copyright 2014 Rob Landley <rob@landley.net>
   4 *
   5 * No standard
   6
   7USE_BASE64(NEWTOY(base64, "diw#<0=76[!dw]", TOYFLAG_USR|TOYFLAG_BIN))
   8
   9config BASE64
  10  bool "base64"
  11  default y
  12  help
  13    usage: base64 [-di] [-w COLUMNS] [FILE...]
  14
  15    Encode or decode in base64.
  16
  17    -d  Decode
  18    -i  Ignore non-alphabetic characters
  19    -w  Wrap output at COLUMNS (default 76 or 0 for no wrap)
  20*/
  21
  22#define FOR_base64
  23#include "toys.h"
  24
  25GLOBALS(
  26  long w;
  27
  28  unsigned total;
  29)
  30
  31static void wraputchar(int c, int *x)
  32{
  33  putchar(c);
  34  TT.total++;
  35  if (TT.w && ++*x == TT.w) {
  36    *x = 0;
  37    xputc('\n');
  38  };
  39}
  40
  41static void do_base64(int fd, char *name)
  42{
  43  int out = 0, bits = 0, x = 0, i, len;
  44  char *buf = toybuf+128;
  45
  46  TT.total = 0;
  47
  48  for (;;) {
  49    // If no more data, flush buffer
  50    if (!(len = xread(fd, buf, sizeof(toybuf)-128))) {
  51      if (!(toys.optflags & FLAG_d)) {
  52        if (bits) wraputchar(toybuf[out<<(6-bits)], &x);
  53        while (TT.total&3) wraputchar('=', &x);
  54        if (x) xputc('\n');
  55      }
  56
  57      return;
  58    }
  59
  60    for (i=0; i<len; i++) {
  61      if (toys.optflags & FLAG_d) {
  62        if (buf[i] == '=') return;
  63
  64        if ((x = stridx(toybuf, buf[i])) != -1) {
  65          out = (out<<6) + x;
  66          bits += 6;
  67          if (bits >= 8) {
  68            putchar(out >> (bits -= 8));
  69            out &= (1<<bits)-1;
  70            if (ferror(stdout)) perror_exit(0);
  71          }
  72
  73          continue;
  74        }
  75        if (buf[i] == '\n' || (toys.optflags & FLAG_i)) continue;
  76
  77        break;
  78      } else {
  79        out = (out<<8) + buf[i];
  80        bits += 8;
  81        while (bits >= 6) {
  82          wraputchar(toybuf[out >> (bits -= 6)], &x);
  83          out &= (1<<bits)-1;
  84        }
  85      }
  86    }
  87  }
  88}
  89
  90void base64_main(void)
  91{
  92  base64_init(toybuf);
  93  loopfiles(toys.optargs, do_base64);
  94}
  95