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/*
 *  sponge.c - read in all available info from stdin, then output it to
 *  file named on the command line
 *
 *  Copyright ©  2006  Tollef Fog Heen
 *
 *  This program is free software; you can redistribute it and/or
 *  modify it under the terms of the GNU General Public License
 *  version 2 as published by the Free Software Foundation.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 *  General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
 * USA
 *
 */

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <errno.h>
#include <string.h>

void usage() {
  printf("sponge <file>: suck in all input from stdin and write it to <file>");
  exit(0);
}

int main(int argc, char **argv) {
  char *buf, *bufstart;
  size_t bufsize = 8192;
  size_t bufused = 0;
  ssize_t i = 0;
  int outfd;
  if (argc != 2) {
    usage();
  }
  
  bufstart = buf = malloc(bufsize);
  if (!buf) {
    perror("malloc");
    exit(1);
  }

  while ((i = read(0, buf, bufsize - bufused)) > 0) {
    bufused = bufused+i;
    if (bufused == bufsize) {
      bufsize *= 2;
      bufstart = realloc(bufstart, bufsize);
      if (!bufstart) {
        perror("realloc");
        exit(1);
      }

      buf = bufstart + bufused;
    }
  }
  if (i == -1) {
    perror("read");
    exit(1);
  }
  
  outfd = open(argv[1], O_CREAT | O_TRUNC | O_WRONLY, 
               0666);
  if (outfd == -1) {
    fprintf(stderr, "Can't open %s: %s\n", argv[1], strerror(errno));
    exit(1);
  }

  i = write(outfd, bufstart, bufused);
  if (i == -1) {
    perror("write");
    exit(1);
  }

  i = close(outfd);
  if (i == -1) {
    perror("close");
    exit(1);
  }

  return 0;
}