- add libbb function str_tolower to convert a string to lowercase.

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

diff --git a/coreutils/watch.c b/coreutils/watch.c
index 9da591b483bc8b21f54c530d2affe0b75486f010..60a4a71ceabd85d678b43438618d2dec9e89b817 100644 (file)
--- a/coreutils/watch.c
+++ b/coreutils/watch.c
@@ -3,106 +3,78 @@
  * Mini watch implementation for busybox
  *
  * Copyright (C) 2001 by Michael Habermann <mhabermann@gmx.de>
+ * Copyrigjt (C) Mar 16, 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
- * 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.
  */
 
 /* 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 <stdlib.h>
-#include <string.h>
-#include <limits.h>
-#include <time.h>
-#include <assert.h>
-#include <unistd.h>
-#include <sys/wait.h>
 #include "busybox.h"
 
+// procps 2.0.18:
+// watch [-d] [-n seconds]
+//   [--differences[=cumulative]] [--interval=seconds] command
+//
+// procps-3.2.3:
+// watch [-dt] [-n seconds]
+//   [--differences[=cumulative]] [--interval=seconds] [--no-title] command
+//
+// (procps 3.x and procps 2.x are forks, not newer/older versions of the same)
+
+int watch_main(int argc, char **argv);
 int watch_main(int argc, char **argv)
 {
-       const int header_len = 40;
-       time_t t;
-       pid_t pid;
+       unsigned opt;
        unsigned period = 2;
-       int old_stdout;
-       int len, len2;
-       char **watched_argv;
-       char header[header_len + 1];
+       unsigned cmdlen = 1; // 1 for terminal NUL
+       char *header = NULL;
+       char *cmd;
+       char *tmp;
+       char **p;
 
-       if (argc < 2) {
-               bb_show_usage();
-       }
+       opt_complementary = "-1"; // at least one param please
+       opt = getopt32(argc, argv, "+dtn:", &tmp);
+       //if (opt & 0x1) // -d (ignore)
+       //if (opt & 0x2) // -t
+       if (opt & 0x4) period = xatou(tmp);
+       argv += optind;
 
-       /* 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;
+       p = argv;
+       while (*p)
+               cmdlen += strlen(*p++) + 1;
+       tmp = cmd = xmalloc(cmdlen);
+       while (*argv) {
+               tmp += sprintf(tmp, " %s", *argv);
+               argv++;
        }
-       watched_argv = argv;
-
-       /* create header */
-
-       len = snprintf(header, header_len, "Every %ds:", period);
-       /* Don't bother checking for len < 0, as it should never happen.
-        * But, just to be prepared... */
-       assert(len >= 0);
-       do {
-               len2 = strlen(*argv);
-               if (len + len2 >= header_len-1) {
-                       break;
-               }
-               header[len] = ' ';
-               memcpy(header+len+1, *argv, len2);
-               len += len2+1;
-       } while (*++argv);
-
-       header[len] = 0;
-
-       /* thanks to lye, who showed me how to redirect stdin/stdout */
-       old_stdout = dup(STDOUT_FILENO);
+       cmd++; // skip initial space
 
        while (1) {
-               time(&t);
-               /* Use dprintf to avoid fflush()ing stdout. */
-               if (dprintf(1, "\033[H\033[J%-*s%s\n", header_len, header, ctime(&t)) < 0) {
-                       bb_perror_msg_and_die("printf");
-               }
+               printf("\033[H\033[J");
+               if (!(opt & 0x2)) { // no -t
+                       int width, len;
+                       char *thyme;
+                       time_t t;
 
-               pid = vfork();  /* vfork, because of ucLinux */
-               if (pid > 0) {
-                       //parent
-                       wait(0);
-                       sleep(period);
-               } else if (0 == pid) {
-                       //child
-                       dup2(old_stdout, STDOUT_FILENO);
-                       execvp(*watched_argv, watched_argv);
-                       bb_perror_msg_and_die(*watched_argv);
-               } else {
-                       bb_perror_msg_and_die("vfork");
+                       get_terminal_width_height(STDOUT_FILENO, &width, 0);
+                       header = xrealloc(header, width--);
+                       // '%-*s' pads header with spaces to the full width
+                       snprintf(header, width, "Every %ds: %-*s", period, width, cmd);
+                       time(&t);
+                       thyme = ctime(&t);
+                       len = strlen(thyme);
+                       if (len < width)
+                               strcpy(header + width - len, thyme);
+                       puts(header);
                }
+               fflush(stdout);
+               // TODO: 'real' watch pipes cmd's output to itself
+               // and does not allow it to overflow the screen
+               // (taking into account linewrap!)
+               system(cmd);
+               sleep(period);
        }
+       return 0; // gcc thinks we can reach this :)
 }