summaryrefslogtreecommitdiff
path: root/coreutils/watch.c
diff options
context:
space:
mode:
authorGlenn L McGrath2002-09-16 09:10:04 +0000
committerGlenn L McGrath2002-09-16 09:10:04 +0000
commit18b76e6f8047edf2e9e3d8fcc962a2e40ed8ffbd (patch)
treea43358d389b2e594341e993c7a86d44369244423 /coreutils/watch.c
parent8fede28c7408b2231a50c88da22c2e07f26f6d56 (diff)
downloadbusybox-18b76e6f8047edf2e9e3d8fcc962a2e40ed8ffbd.zip
busybox-18b76e6f8047edf2e9e3d8fcc962a2e40ed8ffbd.tar.gz
Watch applet by Michael Habermann
Diffstat (limited to 'coreutils/watch.c')
-rw-r--r--coreutils/watch.c104
1 files changed, 104 insertions, 0 deletions
diff --git a/coreutils/watch.c b/coreutils/watch.c
new file mode 100644
index 0000000..78ede4c
--- /dev/null
+++ b/coreutils/watch.c
@@ -0,0 +1,104 @@
+/* vi: set sw=4 ts=4: */
+/*
+ * Mini watch implementation for busybox
+ *
+ * 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
+ *
+ */
+
+/* getopt not needed */
+
+#include <stdio.h>
+#include <errno.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <string.h>
+#include "busybox.h"
+
+extern int watch_main(int argc, char **argv)
+{
+ const char date_argv[2][10] = { "date", "" };
+ const char clrscr[] =
+ "\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n";
+ 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;
+
+ if (argc < 2) {
+ show_usage();
+ } else {
+ cargv = argv + 1;
+ cargc = argc - 1;
+
+ /* 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;
+ }
+ }
+
+
+ /* 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, " ");
+ }
+
+ /* fill with blanks */
+ for (i = strlen(header); i < header_len; i++)
+ header[i] = ' ';
+
+ header[header_len - 1] = '\0';
+
+
+ /* thanks to lye, who showed me how to redirect stdin/stdout */
+ old_stdout = dup(1);
+
+ while (1) {
+ printf("%s%s", clrscr, 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");
+ }
+ }
+
+
+ return EXIT_SUCCESS;
+}