busybox/procps/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 "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) MAIN_EXTERNALLY_VISIBLE;
int watch_main(int argc UNUSED_PARAM, char **argv)
{
	unsigned opt;
	unsigned period = 2;
	unsigned width, new_width;
	char *header;
	char *cmd;

#if 0 // maybe ENABLE_DESKTOP?
	// procps3 compat - "echo TEST | watch cat" doesn't show TEST:
	close(STDIN_FILENO);
	xopen("/dev/null", O_RDONLY);
#endif

	opt_complementary = "-1:n+"; // at least one param; -n NUM
	// "+": stop at first non-option (procps 3.x only)
	opt = getopt32(argv, "+dtn:", &period);
	argv += optind;

	// watch from both procps 2.x and 3.x does concatenation. Example:
	// watch ls -l "a /tmp" "2>&1" - ls won't see "a /tmp" as one param
	cmd = *argv;
	while (*++argv)
		cmd = xasprintf("%s %s", cmd, *argv); // leaks cmd

	width = (unsigned)-1; // make sure first time new_width != width
	header = NULL;
	while (1) {
		/* home; clear to the end of screen */
		printf("\033[H""\033[J");
		if (!(opt & 0x2)) { // no -t
			const unsigned time_len = sizeof("1234-67-90 23:56:89");
			time_t t;

			// STDERR_FILENO is procps3 compat:
			// "watch ls 2>/dev/null" does not detect tty size
			get_terminal_width_height(STDERR_FILENO, &new_width, NULL);
			if (new_width != width) {
				width = new_width;
				free(header);
				header = xasprintf("Every %us: %-*s", period, (int)width, cmd);
			}
			time(&t);
			if (time_len < width)
				strftime(header + width - time_len, time_len,
					"%Y-%m-%d %H:%M:%S", localtime(&t));

			// compat: empty line between header and cmd output
			printf("%s\n\n", header);
		}
		fflush_all();
		// 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	niro	816	/* 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 "libbb.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) MAIN_EXTERNALLY_VISIBLE;
27			int watch_main(int argc UNUSED_PARAM, char **argv)
28			{
29			unsigned opt;
30			unsigned period = 2;
31			unsigned width, new_width;
32			char *header;
33			char *cmd;
34
35	niro	984	#if 0 // maybe ENABLE_DESKTOP?
36			// procps3 compat - "echo TEST \| watch cat" doesn't show TEST:
37			close(STDIN_FILENO);
38			xopen("/dev/null", O_RDONLY);
39			#endif
40
41	niro	816	opt_complementary = "-1:n+"; // at least one param; -n NUM
42			// "+": stop at first non-option (procps 3.x only)
43			opt = getopt32(argv, "+dtn:", &period);
44			argv += optind;
45
46			// watch from both procps 2.x and 3.x does concatenation. Example:
47	niro	984	// watch ls -l "a /tmp" "2>&1" - ls won't see "a /tmp" as one param
48	niro	816	cmd = *argv;
49			while (*++argv)
50			cmd = xasprintf("%s %s", cmd, *argv); // leaks cmd
51
52			width = (unsigned)-1; // make sure first time new_width != width
53			header = NULL;
54			while (1) {
55	niro	1123	/* home; clear to the end of screen */
56			printf("\033[H""\033[J");
57	niro	816	if (!(opt & 0x2)) { // no -t
58			const unsigned time_len = sizeof("1234-67-90 23:56:89");
59			time_t t;
60
61	niro	984	// STDERR_FILENO is procps3 compat:
62			// "watch ls 2>/dev/null" does not detect tty size
63			get_terminal_width_height(STDERR_FILENO, &new_width, NULL);
64	niro	816	if (new_width != width) {
65			width = new_width;
66			free(header);
67			header = xasprintf("Every %us: %-*s", period, (int)width, cmd);
68			}
69			time(&t);
70			if (time_len < width)
71			strftime(header + width - time_len, time_len,
72			"%Y-%m-%d %H:%M:%S", localtime(&t));
73
74	niro	984	// compat: empty line between header and cmd output
75			printf("%s\n\n", header);
76	niro	816	}
77	niro	984	fflush_all();
78	niro	816	// TODO: 'real' watch pipes cmd's output to itself
79			// and does not allow it to overflow the screen
80			// (taking into account linewrap!)
81			system(cmd);
82			sleep(period);
83			}
84			return 0; // gcc thinks we can reach this :)
85			}