source: trunk/minix/commands/simple/tee.c@ 10

/* tee - pipe fitting                   Author: Paul Polderman */

#include <sys/types.h>
#include <fcntl.h>
#include <signal.h>
#include <unistd.h>
#include <stdlib.h>
#include <minix/minlib.h>

#define MAXFD   18
#define CHUNK_SIZE      4096

int fd[MAXFD];

_PROTOTYPE(int main, (int argc, char **argv));

int main(argc, argv)
int argc;
char **argv;
{
  char iflag = 0, aflag = 0;
  char buf[CHUNK_SIZE];
  int i, s, n;

  argv++;
  --argc;
  while (argc > 0 && argv[0][0] == '-') {
        switch (argv[0][1]) {
            case 'i':           /* Interrupt turned off. */
                iflag++;
                break;
            case 'a':           /* Append to outputfile(s), instead of
                         * overwriting them. */
                aflag++;
                break;
            default:
                std_err("Usage: tee [-i] [-a] [files].\n");
                exit(1);
        }
        argv++;
        --argc;
  }
  fd[0] = 1;                    /* Always output to stdout. */
  for (s = 1; s < MAXFD && argc > 0; --argc, argv++, s++) {
        if (aflag && (fd[s] = open(*argv, O_RDWR)) >= 0) {
                lseek(fd[s], 0L, SEEK_END);
                continue;
        } else {
                if ((fd[s] = creat(*argv, 0666)) >= 0) continue;
        }
        std_err("Cannot open output file: ");
        std_err(*argv);
        std_err("\n");
        exit(2);
  }

  if (iflag) signal(SIGINT, SIG_IGN);

  while ((n = read(0, buf, CHUNK_SIZE)) > 0) {
        for (i = 0; i < s; i++) write(fd[i], buf, n);
  }

  for (i = 0; i < s; i++)       /* Close all fd's */
        close(fd[i]);
  return(0);
}