1 files changed, 80 insertions, 0 deletions
diff --git a/procps/watch.c b/procps/watch.c
new file mode 100644
index 0000000..2ad0564
--- /dev/null
+++ b/procps/watch.c
@@ -0,0 +1,80 @@
+/* vi: set sw=4 ts=4: */
+/*
+ * 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)
+ *
+ * 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. */
+
+#include "libbb.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)
+{
+	unsigned opt;
+	unsigned period = 2;
+	unsigned cmdlen = 1; // 1 for terminal NUL
+	char *header = NULL;
+	char *cmd;
+	char *tmp;
+	char **p;
+
+	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;
+
+	p = argv;
+	while (*p)
+		cmdlen += strlen(*p++) + 1;
+	tmp = cmd = xmalloc(cmdlen);
+	while (*argv) {
+		tmp += sprintf(tmp, " %s", *argv);
+		argv++;
+	}
+	cmd++; // skip initial space
+
+	while (1) {
+		printf("\033[H\033[J");
+		if (!(opt & 0x2)) { // no -t
+			int width, len;
+			char *thyme;
+			time_t t;
+
+			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 :)
+}