1 /* vi: set sw=4 ts=4: */
3 * Mini watch implementation for busybox
5 * Copyright (C) 2001 by Michael Habermann <mhabermann@gmx.de>
6 * Copyrigjt (C) Mar 16, 2003 Manuel Novoa III (mjn3@codepoet.org)
8 * Licensed under GPLv2 or later, see file LICENSE in this source tree.
11 /* BB_AUDIT SUSv3 N/A */
12 /* BB_AUDIT GNU defects -- only option -n is supported. */
14 //usage:#define watch_trivial_usage
15 //usage: "[-n SEC] [-t] PROG ARGS"
16 //usage:#define watch_full_usage "\n\n"
17 //usage: "Run PROG periodically\n"
18 //usage: "\n -n Loop period in seconds (default 2)"
19 //usage: "\n -t Don't print header"
21 //usage:#define watch_example_usage
22 //usage: "$ watch date\n"
23 //usage: "Mon Dec 17 10:31:40 GMT 2000\n"
24 //usage: "Mon Dec 17 10:31:42 GMT 2000\n"
25 //usage: "Mon Dec 17 10:31:44 GMT 2000"
30 // watch [-d] [-n seconds]
31 // [--differences[=cumulative]] [--interval=seconds] command
34 // watch [-dt] [-n seconds]
35 // [--differences[=cumulative]] [--interval=seconds] [--no-title] command
37 // (procps 3.x and procps 2.x are forks, not newer/older versions of the same)
39 int watch_main(int argc
, char **argv
) MAIN_EXTERNALLY_VISIBLE
;
40 int watch_main(int argc UNUSED_PARAM
, char **argv
)
44 unsigned width
, new_width
;
48 #if 0 // maybe ENABLE_DESKTOP?
49 // procps3 compat - "echo TEST | watch cat" doesn't show TEST:
51 xopen("/dev/null", O_RDONLY
);
54 opt_complementary
= "-1:n+"; // at least one param; -n NUM
55 // "+": stop at first non-option (procps 3.x only)
56 opt
= getopt32(argv
, "+dtn:", &period
);
59 // watch from both procps 2.x and 3.x does concatenation. Example:
60 // watch ls -l "a /tmp" "2>&1" - ls won't see "a /tmp" as one param
63 cmd
= xasprintf("%s %s", cmd
, *argv
); // leaks cmd
65 width
= (unsigned)-1; // make sure first time new_width != width
68 /* home; clear to the end of screen */
69 printf("\033[H""\033[J");
70 if (!(opt
& 0x2)) { // no -t
71 const unsigned time_len
= sizeof("1234-67-90 23:56:89");
74 // STDERR_FILENO is procps3 compat:
75 // "watch ls 2>/dev/null" does not detect tty size
76 get_terminal_width_height(STDERR_FILENO
, &new_width
, NULL
);
77 if (new_width
!= width
) {
80 header
= xasprintf("Every %us: %-*s", period
, (int)width
, cmd
);
84 strftime(header
+ width
- time_len
, time_len
,
85 "%Y-%m-%d %H:%M:%S", localtime(&t
));
87 // compat: empty line between header and cmd output
88 printf("%s\n\n", header
);
91 // TODO: 'real' watch pipes cmd's output to itself
92 // and does not allow it to overflow the screen
93 // (taking into account linewrap!)
97 return 0; // gcc thinks we can reach this :)