Disable any buffering to stdout

[oweals/busybox.git] / coreutils / tee.c

diff --git a/coreutils/tee.c b/coreutils/tee.c
index aa3098c6a580873618e52bdac65966d1482f46b1..73c2f8e9df406c6f0f790141ebdd835a5ddf32be 100644 (file)
--- a/coreutils/tee.c
+++ b/coreutils/tee.c
@@ -1,9 +1,8 @@
 /* vi: set sw=4 ts=4: */
 /*
- * Mini tee implementation for busybox
+ * tee implementation for busybox
  *
- * Copyright (C) 1999,2000,2001 by Lineo, inc.
- * Written by Matt Kraai <kraai@alumni.carnegiemellon.edu>
+ * Copyright (C) 2003  Manuel Novoa III  <mjn3@codepoet.org>
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -21,48 +20,97 @@
  *
  */
 
-#include "busybox.h"
-#include <getopt.h>
+/* BB_AUDIT SUSv3 compliant */
+/* http://www.opengroup.org/onlinepubs/007904975/utilities/tee.html */
+
 #include <stdio.h>
+#include <stdlib.h>
+#include <signal.h>
+#include <unistd.h>
+#include "busybox.h"
 
-int
-tee_main(int argc, char **argv)
+int tee_main(int argc, char **argv)
 {
-       char *mode = "w";
-       int c, i, status = 0, nfiles = 0;
+       const char *mode = "w\0a";
        FILE **files;
+       FILE **p;
+       char **filenames;
+       int flags;
+       int retval = EXIT_SUCCESS;
+#ifdef CONFIG_FEATURE_TEE_USE_BLOCK_IO
+       size_t c;
+       RESERVE_CONFIG_BUFFER(buf, BUFSIZ);
+#else
+       int c;
+#endif
+
+       flags = bb_getopt_ulflags(argc, argv, "ia");    /* 'a' must be 2nd */
+
+       mode += (flags & 2);    /* Since 'a' is the 2nd option... */
+
+       if (flags & 1) {
+               signal(SIGINT, SIG_IGN);        /* TODO - switch to sigaction.*/
+       }
+
+       /* gnu tee ignores SIGPIPE in case one of the output files is a pipe
+        * that doesn't consume all its input.  Good idea... */
+       signal(SIGPIPE, SIG_IGN);               /* TODO - switch to sigaction.*/
 
-       while ((c = getopt(argc, argv, "a")) != EOF) {
-               switch (c) {
-               case 'a': 
-                       mode = "a";
-                       break;
-               default:
-                       usage(tee_usage);
+       /* Allocate an array of FILE *'s, with one extra for a sentinal. */
+       p = files = (FILE **)xmalloc(sizeof(FILE *) * (argc - optind + 2));
+       *p = stdout;
+       argv += optind - 1;
+       filenames = argv - 1;
+       *filenames = (char *) bb_msg_standard_input;    /* for later */
+       goto GOT_NEW_FILE;
+
+       do {
+               if ((*p = bb_wfopen(*argv, mode)) == NULL) {
+                       retval = EXIT_FAILURE;
+                       continue;
+               }
+               filenames[(int)(p - files)] = *argv;
+       GOT_NEW_FILE:
+               setbuf(*p, NULL);       /* tee must not buffer output. */
+               ++p;
+       } while (*++argv);
+
+       *p = NULL;                              /* Store the sentinal value. */
+
+#ifdef CONFIG_FEATURE_TEE_USE_BLOCK_IO
+       while ((c = fread(buf, 1, BUFSIZ, stdin)) != 0) {
+               for (p=files ; *p ; p++) {
+                       fwrite(buf, 1, c, *p);
                }
        }
 
-       files = (FILE **)xmalloc(sizeof(FILE *) * (argc - optind + 1));
-       files[nfiles++] = stdout;
-       while (optind < argc) {
-               if ((files[nfiles++] = fopen(argv[optind++], mode)) == NULL) {
-                       nfiles--;
-                       perror_msg("%s", argv[optind-1]);
-                       status = 1;
+#ifdef CONFIG_FEATURE_CLEAN_UP
+       RELEASE_CONFIG_BUFFER(buf);
+#endif
+
+#else
+       setvbuf(stdout, NULL, _IONBF, 0);
+       while ((c = getchar()) != EOF) {
+               for (p=files ; *p ; p++) {
+                       putc(c, *p);
                }
        }
+#endif
 
-       while ((c = getchar()) != EOF)
-               for (i = 0; i < nfiles; i++)
-                       putc(c, files[i]);
+       /* Now we need to check for i/o errors on stdin and the various 
+        * output files.  Since we know that the first entry in the output
+        * file table is stdout, we can save one "if ferror" test by
+        * setting the first entry to stdin and checking stdout error
+        * status with bb_fflush_stdout_and_exit()... although fflush()ing
+        * is unnecessary here. */
 
-       return status;
-}
+       p = files;
+       *p = stdin;
+       do {            /* Now check for (input and) output errors. */
+               /* Checking ferror should be sufficient, but we may want to fclose.
+                * If we do, remember not to close stdin! */
+               bb_xferror(*p, filenames[(int)(p - files)]);
+       } while (*++p);
 
-/*
-Local Variables:
-c-file-style: "linux"
-c-basic-offset: 4
-tab-width: 4
-End:
-*/
+       bb_fflush_stdout_and_exit(retval);
+}