toys/other/base64.c

/* base64.c - Encode and decode base64
 *
 * Copyright 2014 Rob Landley <rob@landley.net>
 *
 * No standard

USE_BASE64(NEWTOY(base64, "diw#<1[!dw]", TOYFLAG_USR|TOYFLAG_BIN))

config BASE64
  bool "base64"
  default y
  help
    usage: base64 [-di] [-w COLUMNS] [FILE...]

    Encode or decode in base64.

    -d	decode
    -i	ignore non-alphabetic characters
    -w	wrap output at COLUMNS (default 76)
*/

#define FOR_base64
#include "toys.h"

GLOBALS(
  long columns;
)

static void do_base64(int fd, char *name)
{
  int out = 0, bits = 0, x = 0, i, len;
  char *buf = toybuf+128;

  for (;;) {
    if (!(len = xread(fd, buf, sizeof(toybuf)-128))) {
      if (!(toys.optflags & FLAG_d)) {
        if (bits) {
          putchar(toybuf[out<<(6-bits)]);
          x++;
        }
        while (x++&3)  putchar('=');
        if (x != 1) xputc('\n');
      }

      return;
    }
    for (i=0; i<len; i++) {
      if (toys.optflags & FLAG_d) {
        if (buf[i] == '=') return;

        if ((x = stridx(toybuf, buf[i])) != -1) {
          out = (out<<6) + x;
          bits += 6;
          if (bits >= 8) {
            putchar(out >> (bits -= 8));
            out &= (1<<bits)-1;
            if (ferror(stdout)) perror_exit(0);
          }

          continue;
        }
        if (buf[i] == '\n' || (toys.optflags & FLAG_i)) continue;

        break;
      } else {
        out = (out<<8) + buf[i];
        bits += 8;
        while (bits >= 6) {
          putchar(toybuf[out >> (bits -= 6)]);
          out &= (1<<bits)-1;
          if (TT.columns == ++x) {
            xputc('\n');
            x = 0;
          }
        }
      }
    }
  }
}

void base64_main(void)
{
  if (!TT.columns) TT.columns = 76;

  base64_init(toybuf);
  loopfiles(toys.optargs, do_base64);
}