busybox/coreutils/watch.c

/* 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 "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)
{
	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 :)
}
1	/* vi: set sw=4 ts=4: */
2	/*
3	* Mini watch implementation for busybox
4	*
5	* Copyright (C) 2001 by Michael Habermann <mhabermann@gmx.de>
6	* Copyrigjt (C) Mar 16, 2003 Manuel Novoa III (mjn3@codepoet.org)
7	*
8	* Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
9	*/
10
11	/* BB_AUDIT SUSv3 N/A */
12	/* BB_AUDIT GNU defects -- only option -n is supported. */
13
14	#include "busybox.h"
15
16	// procps 2.0.18:
17	// watch [-d] [-n seconds]
18	// [--differences[=cumulative]] [--interval=seconds] command
19	//
20	// procps-3.2.3:
21	// watch [-dt] [-n seconds]
22	// [--differences[=cumulative]] [--interval=seconds] [--no-title] command
23	//
24	// (procps 3.x and procps 2.x are forks, not newer/older versions of the same)
25
26	int watch_main(int argc, char **argv)
27	{
28	unsigned opt;
29	unsigned period = 2;
30	unsigned cmdlen = 1; // 1 for terminal NUL
31	char *header = NULL;
32	char *cmd;
33	char *tmp;
34	char **p;
35
36	opt_complementary = "-1"; // at least one param please
37	opt = getopt32(argc, argv, "+dtn:", &tmp);
38	//if (opt & 0x1) // -d (ignore)
39	//if (opt & 0x2) // -t
40	if (opt & 0x4) period = xatou(tmp);
41	argv += optind;
42
43	p = argv;
44	while (*p)
45	cmdlen += strlen(*p++) + 1;
46	tmp = cmd = xmalloc(cmdlen);
47	while (*argv) {
48	tmp += sprintf(tmp, " %s", *argv);
49	argv++;
50	}
51	cmd++; // skip initial space
52
53	while (1) {
54	printf("\033[H\033[J");
55	if (!(opt & 0x2)) { // no -t
56	int width, len;
57	char *thyme;
58	time_t t;
59
60	get_terminal_width_height(STDOUT_FILENO, &width, 0);
61	header = xrealloc(header, width--);
62	// '%-*s' pads header with spaces to the full width
63	snprintf(header, width, "Every %ds: %-*s", period, width, cmd);
64	time(&t);
65	thyme = ctime(&t);
66	len = strlen(thyme);
67	if (len < width)
68	strcpy(header + width - len, thyme);
69	puts(header);
70	}
71	fflush(stdout);
72	// TODO: 'real' watch pipes cmd's output to itself
73	// and does not allow it to overflow the screen
74	// (taking into account linewrap!)
75	system(cmd);
76	sleep(period);
77	}
78	return 0; // gcc thinks we can reach this :)
79	}