i86/elks/elkscmd/minix3/tee.c

   1 /* tee - pipe fitting                   Author: Paul Polderman */
   2
   3 #include <stdio.h>
   4 #include <sys/types.h>
   5 #include <fcntl.h>
   6 #include <signal.h>
   7 #include <unistd.h>
   8 #include <stdlib.h>
   9 #if 0
  10 #include <minix/minlib.h>
  11 #endif
  12 #include "defs.h"
  13
  14 #define MAXFD   18
  15 #define CHUNK_SIZE      4096
  16
  17 int fd[MAXFD];
  18
  19 _PROTOTYPE(int main, (int argc, char **argv));
  20
  21 int main(argc, argv)
  22 int argc;
  23 char **argv;
  24 {
  25   char iflag = 0, aflag = 0;
  26   char buf[CHUNK_SIZE];
  27   int i, s, n;
  28
  29   argv++;
  30   --argc;
  31   while (argc > 0 && argv[0][0] == '-') {
  32         switch (argv[0][1]) {
  33             case 'i':           /* Interrupt turned off. */
  34                 iflag++;
  35                 break;
  36             case 'a':           /* Append to outputfile(s), instead of
  37                          * overwriting them. */
  38                 aflag++;
  39                 break;
  40             default:
  41                 fprintf(stderr,"Usage: tee [-i] [-a] [files].\n");
  42                 exit(1);
  43         }
  44         argv++;
  45         --argc;
  46   }
  47   fd[0] = 1;                    /* Always output to stdout. */
  48   for (s = 1; s < MAXFD && argc > 0; --argc, argv++, s++) {
  49         if (aflag && (fd[s] = open(*argv, O_RDWR)) >= 0) {
  50                 lseek(fd[s], 0L, SEEK_END);
  51                 continue;
  52         } else {
  53                 if ((fd[s] = creat(*argv, 0666)) >= 0) continue;
  54         }
  55         fprintf(stderr,"Cannot open output file: ");
  56         fprintf(stderr,*argv);
  57         fprintf(stderr,"\n");
  58         exit(2);
  59   }
  60
  61   if (iflag) signal(SIGINT, SIG_IGN);
  62
  63   while ((n = read(0, buf, CHUNK_SIZE)) > 0) {
  64         for (i = 0; i < s; i++) write(fd[i], buf, n);
  65   }
  66
  67   for (i = 0; i < s; i++)       /* Close all fd's */
  68         close(fd[i]);
  69   return(0);
  70 }