src/tee/tee.c

   1 /*  vim:set ts=4 sw=4:
   2  *
   3  *      Copyright (c) 1996, Paul Slootman
   4  *
   5  *      Author: Paul Slootman
   6  *                      (paul@wurtel.hobby.nl, paul@murphy.nl, paulS@toecompst.nl)
   7  *
   8  *      This source code is released into the public domain. It is provided on an
   9  *      as-is basis and no responsibility is accepted for its failure to perform
  10  *      as expected. It is worth at least as much as you paid for it!
  11  *
  12  * tee.c - pipe fitting
  13  *
  14  * tee reads stdin, and writes what it reads to each of the specified
  15  * files. The primary reason of existence for this version is a quick
  16  * and dirty implementation to distribute with Vim, to make one of the
  17  * most useful features of Vim possible on OS/2: quickfix.
  18  *
  19  * Of course, not using tee but instead redirecting make's output directly
  20  * into a temp file and then processing that is possible, but if we have a
  21  * system capable of correctly piping (unlike DOS, for example), why not
  22  * use it as well as possible? This tee should also work on other systems,
  23  * but it's not been tested there, only on OS/2.
  24  *
  25  * tee is also available in the GNU shellutils package, which is available
  26  * precompiled for OS/2. That one probably works better.
  27  */
  28
  29 #include <unistd.h>
  30 #include <malloc.h>
  31 #include <stdio.h>
  32
  33 void usage(void)
  34 {
  35         fprintf(stderr,
  36 "tee usage:\n\
  37 \ttee [-a] file ... file_n\n\
  38 \n\
  39 \t-a\tappend to files instead of truncating\n\
  40 \nTee reads its input, and writes to each of the specified files,\n\
  41 as well as to the standard output.\n\
  42 \n\
  43 This version supplied with Vim 4.2 to make ':make' possible.\n\
  44 For a more complete and stable version, consider getting\n\
  45 [a port of] the GNU shellutils package.\n\
  46 ");
  47 }
  48
  49 /*
  50  * fread only returns when count is read or at EOF.
  51  * We could use fgets, but I want to be able to handle binary blubber.
  52  */
  53
  54 int
  55 myfread(char *buf, int elsize /*ignored*/, int max, FILE *fp)
  56 {
  57         int     c;
  58         int     n = 0;
  59
  60         while ((n < max) && ((c = getchar()) != EOF))
  61         {
  62                 *(buf++) = c;
  63                 n++;
  64                 if (c == '\n' || c == '\r')
  65                         break;
  66         }
  67         return n;
  68 }
  69
  70
  71 void
  72 main(int argc, char *argv[])
  73 {
  74         int     append = 0;
  75         int     numfiles;
  76         int     opt;
  77         int     maxfiles;
  78         FILE    **filepointers;
  79         int     i;
  80         char    buf[BUFSIZ];
  81         int     n;
  82         extern int      optind;
  83
  84         while ((opt = getopt(argc, argv, "a")) != EOF)
  85         {
  86                 switch (opt)
  87                 {
  88                         case 'a':       append++;
  89                                         break;
  90                         default:        usage();
  91                                         exit(2);
  92                 }
  93         }
  94
  95         numfiles = argc - optind;
  96
  97         if (numfiles == 0)
  98         {
  99                 fprintf(stderr, "doesn't make much sense using tee without any file name arguments...\n");
 100                 usage();
 101                 exit(2);
 102         }
 103
 104         maxfiles = sysconf(_SC_OPEN_MAX);       /* or fill in 10 or so */
 105         if (maxfiles < 0)
 106                 maxfiles = 10;
 107         if (numfiles + 3 > maxfiles)    /* +3 accounts for stdin, out, err */
 108         {
 109                 fprintf(stderr, "Sorry, there is a limit of max %d files.\n", maxfiles - 3);
 110                 exit(1);
 111         }
 112         filepointers = calloc(numfiles, sizeof(FILE *));
 113         if (filepointers == NULL)
 114         {
 115                 fprintf(stderr, "Error allocating memory for %d files\n", numfiles);
 116                 exit(1);
 117         }
 118         for (i = 0; i < numfiles; i++)
 119         {
 120                 filepointers[i] = fopen(argv[i+optind], append ? "ab" : "wb");
 121                 if (filepointers[i] == NULL)
 122                 {
 123                         fprintf(stderr, "Can't open \"%s\"\n", argv[i+optind]);
 124                         exit(1);
 125                 }
 126         }
 127         _fsetmode(stdin,  "b");
 128         fflush(stdout); /* needed for _fsetmode(stdout) */
 129         _fsetmode(stdout, "b");
 130
 131         while ((n = myfread(buf, sizeof(char), sizeof(buf), stdin)) > 0)
 132         {
 133                 fwrite(buf, sizeof(char), n, stdout);
 134                 fflush(stdout);
 135                 for (i = 0; i < numfiles; i++)
 136                 {
 137                         if (filepointers[i] &&
 138                              fwrite(buf, sizeof(char), n, filepointers[i]) != n)
 139                         {
 140                                 fprintf(stderr, "Error writing to file \"%s\"\n", argv[i+optind]);
 141                                 fclose(filepointers[i]);
 142                                 filepointers[i] = NULL;
 143                         }
 144                 }
 145         }
 146         for (i = 0; i < numfiles; i++)
 147         {
 148                 if (filepointers[i])
 149                         fclose(filepointers[i]);
 150         }
 151
 152         exit(0);
 153 }