release/src/router/busybox/coreutils/tee.c

   1 /* vi: set sw=4 ts=4: */
   2 /*
   3  * tee implementation for busybox
   4  *
   5  * Copyright (C) 2003  Manuel Novoa III  <mjn3@codepoet.org>
   6  *
   7  * Licensed under GPLv2 or later, see file LICENSE in this source tree.
   8  */
   9
  10 /* BB_AUDIT SUSv3 compliant */
  11 /* http://www.opengroup.org/onlinepubs/007904975/utilities/tee.html */
  12
  13 //usage:#define tee_trivial_usage
  14 //usage:       "[-ai] [FILE]..."
  15 //usage:#define tee_full_usage "\n\n"
  16 //usage:       "Copy stdin to each FILE, and also to stdout\n"
  17 //usage:     "\n        -a      Append to the given FILEs, don't overwrite"
  18 //usage:     "\n        -i      Ignore interrupt signals (SIGINT)"
  19 //usage:
  20 //usage:#define tee_example_usage
  21 //usage:       "$ echo \"Hello\" | tee /tmp/foo\n"
  22 //usage:       "$ cat /tmp/foo\n"
  23 //usage:       "Hello\n"
  24
  25 #include "libbb.h"
  26 #include "common_bufsiz.h"
  27
  28 int tee_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
  29 int tee_main(int argc, char **argv)
  30 {
  31         const char *mode = "w\0a";
  32         FILE **files;
  33         FILE **fp;
  34         char **names;
  35         char **np;
  36         char retval;
  37 //TODO: make unconditional
  38 #if ENABLE_FEATURE_TEE_USE_BLOCK_IO
  39         ssize_t c;
  40 # define buf bb_common_bufsiz1
  41         setup_common_bufsiz();
  42 #else
  43         int c;
  44 #endif
  45         retval = getopt32(argv, "ia");  /* 'a' must be 2nd */
  46         argc -= optind;
  47         argv += optind;
  48
  49         mode += (retval & 2);   /* Since 'a' is the 2nd option... */
  50
  51         if (retval & 1) {
  52                 signal(SIGINT, SIG_IGN); /* TODO - switch to sigaction. (why?) */
  53         }
  54         retval = EXIT_SUCCESS;
  55         /* gnu tee ignores SIGPIPE in case one of the output files is a pipe
  56          * that doesn't consume all its input.  Good idea... */
  57         signal(SIGPIPE, SIG_IGN);
  58
  59         /* Allocate an array of FILE *'s, with one extra for a sentinel. */
  60         fp = files = xzalloc(sizeof(FILE *) * (argc + 2));
  61         np = names = argv - 1;
  62
  63         files[0] = stdout;
  64         goto GOT_NEW_FILE;
  65         do {
  66                 *fp = stdout;
  67                 if (NOT_LONE_DASH(*argv)) {
  68                         *fp = fopen_or_warn(*argv, mode);
  69                         if (*fp == NULL) {
  70                                 retval = EXIT_FAILURE;
  71                                 argv++;
  72                                 continue;
  73                         }
  74                 }
  75                 *np = *argv++;
  76  GOT_NEW_FILE:
  77                 setbuf(*fp, NULL);      /* tee must not buffer output. */
  78                 fp++;
  79                 np++;
  80         } while (*argv);
  81         /* names[0] will be filled later */
  82
  83 #if ENABLE_FEATURE_TEE_USE_BLOCK_IO
  84         while ((c = safe_read(STDIN_FILENO, buf, COMMON_BUFSIZE)) > 0) {
  85                 fp = files;
  86                 do
  87                         fwrite(buf, 1, c, *fp);
  88                 while (*++fp);
  89         }
  90         if (c < 0) {            /* Make sure read errors are signaled. */
  91                 retval = EXIT_FAILURE;
  92         }
  93 #else
  94         setvbuf(stdout, NULL, _IONBF, 0);
  95         while ((c = getchar()) != EOF) {
  96                 fp = files;
  97                 do
  98                         putc(c, *fp);
  99                 while (*++fp);
 100         }
 101 #endif
 102
 103         /* Now we need to check for i/o errors on stdin and the various
 104          * output files.  Since we know that the first entry in the output
 105          * file table is stdout, we can save one "if ferror" test by
 106          * setting the first entry to stdin and checking stdout error
 107          * status with fflush_stdout_and_exit()... although fflush()ing
 108          * is unnecessary here. */
 109         np = names;
 110         fp = files;
 111         names[0] = (char *) bb_msg_standard_input;
 112         files[0] = stdin;
 113         do {    /* Now check for input and output errors. */
 114                 /* Checking ferror should be sufficient, but we may want to fclose.
 115                  * If we do, remember not to close stdin! */
 116                 die_if_ferror(*fp++, *np++);
 117         } while (*fp);
 118
 119         fflush_stdout_and_exit(retval);
 120 }