use bb_xbind/bb_xlisten

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

diff --git a/coreutils/watch.c b/coreutils/watch.c
index c275f3bb3cf6f931f77a566f1f054983ba0504ea..b783d34deb9405020e452fd205e77bf81b56fac1 100644 (file)
--- a/coreutils/watch.c
+++ b/coreutils/watch.c
@@ -4,100 +4,65 @@
  *
  * Copyright (C) 2001 by Michael Habermann <mhabermann@gmx.de>
  *
- * 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
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- * General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
- *
+ * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
  */
 
-/* getopt not needed */
+/* BB_AUDIT SUSv3 N/A */
+/* BB_AUDIT GNU defects -- only option -n is supported. */
+
+/* Mar 16, 2003      Manuel Novoa III   (mjn3@codepoet.org)
+ *
+ * Removed dependency on date_main(), added proper error checking, and
+ * reduced size.
+ */
 
 #include <stdio.h>
-#include <errno.h>
-#include <unistd.h>
 #include <stdlib.h>
 #include <string.h>
+#include <limits.h>
+#include <time.h>
+#include <assert.h>
+#include <unistd.h>
 #include <sys/wait.h>
 #include "busybox.h"
 
-extern int watch_main(int argc, char **argv)
+int watch_main(int argc, char **argv)
 {
-       const char date_argv[2][10] = { "date", "" };
-       const int header_len = 40;
-       char header[header_len + 1];
-       int period = 2;
-       char **cargv;
-       int cargc;
-       pid_t pid;
-       int old_stdout;
-       int i;
+       int width, len;
+       unsigned period = 2;
+       char **watched_argv, *header;
 
-       if (argc < 2) {
-               show_usage();
-       } else {
-               cargv = argv + 1;
-               cargc = argc - 1;
+       if (argc < 2) bb_show_usage();
 
-               /* don't use getopt, because it permutes the arguments */
-               if (argc >= 3 && !strcmp(argv[1], "-n")) {
-                       period = strtol(argv[2], NULL, 10);
-                       if (period < 1)
-                               show_usage();
-                       cargv += 2;
-                       cargc -= 2;
-               }
-       }
+       get_terminal_width_height(1, &width, 0);
+       header = xzalloc(width--);
 
-
-       /* create header */
-       snprintf(header, header_len, "Every %ds: ", period);
-       for (i = 0; i < cargc && (strlen(header) + strlen(cargv[i]) < header_len);
-                i++) {
-               strcat(header, cargv[i]);
-               strcat(header, " ");
+       /* don't use getopt, because it permutes the arguments */
+       ++argv;
+       if ((argc > 3) && !strcmp(*argv, "-n")) {
+               period = bb_xgetularg10_bnd(argv[1], 1, UINT_MAX);
+               argv += 2;
        }
+       watched_argv = argv;
 
-       /* fill with blanks */
-       for (i = strlen(header); i < header_len; i++)
-               header[i] = ' ';
-
-       header[header_len - 1] = '\0';
-
+       /* create header */
 
-       /* thanks to lye, who showed me how to redirect stdin/stdout */
-       old_stdout = dup(1);
+       len = snprintf(header, width, "Every %ds:", period);
+       while (*argv && len<width)
+               snprintf(header+len, width-len, " %s", *(argv++));
 
        while (1) {
-               printf("\033[H\033[J%s", header);
-               date_main(1, (char **) date_argv);
-               printf("\n");
-
-               pid = vfork();  /* vfork, because of ucLinux */
-               if (pid > 0) {
-                       //parent
-                       wait(0);
-                       sleep(period);
-               } else if (0 == pid) {
-                       //child
-                       close(1);
-                       dup(old_stdout);
-                       if (execvp(*cargv, cargv))
-                               error_msg_and_die("Couldn't run command\n");
-               } else {
-                       error_msg_and_die("Couldn't vfork\n");
-               }
-       }
+               char *thyme;
+               time_t t;
 
+               time(&t);
+               thyme = ctime(&t);
+               len = strlen(thyme);
+               if (len < width) header[width-len] = 0;
+               
+               printf("\033[H\033[J%s %s\n", header, thyme);
 
-       return EXIT_SUCCESS;
+               waitpid(bb_xspawn(watched_argv),0,0);
+               sleep(period);
+       }
 }