blob: 0397f21bf2b01a77509920d609188ff85f4e8efb
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 source tree. |
9 | */ |
10 | |
11 | /* BB_AUDIT SUSv3 N/A */ |
12 | /* BB_AUDIT GNU defects -- only option -n is supported. */ |
13 | |
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" |
20 | //usage: |
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" |
26 | |
27 | #include "libbb.h" |
28 | |
29 | // procps 2.0.18: |
30 | // watch [-d] [-n seconds] |
31 | // [--differences[=cumulative]] [--interval=seconds] command |
32 | // |
33 | // procps-3.2.3: |
34 | // watch [-dt] [-n seconds] |
35 | // [--differences[=cumulative]] [--interval=seconds] [--no-title] command |
36 | // |
37 | // (procps 3.x and procps 2.x are forks, not newer/older versions of the same) |
38 | |
39 | int watch_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; |
40 | int watch_main(int argc UNUSED_PARAM, char **argv) |
41 | { |
42 | unsigned opt; |
43 | unsigned period = 2; |
44 | unsigned width, new_width; |
45 | char *header; |
46 | char *cmd; |
47 | |
48 | #if 0 // maybe ENABLE_DESKTOP? |
49 | // procps3 compat - "echo TEST | watch cat" doesn't show TEST: |
50 | close(STDIN_FILENO); |
51 | xopen("/dev/null", O_RDONLY); |
52 | #endif |
53 | |
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); |
57 | argv += optind; |
58 | |
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 |
61 | cmd = *argv; |
62 | while (*++argv) |
63 | cmd = xasprintf("%s %s", cmd, *argv); // leaks cmd |
64 | |
65 | width = (unsigned)-1; // make sure first time new_width != width |
66 | header = NULL; |
67 | while (1) { |
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"); |
72 | |
73 | // STDERR_FILENO is procps3 compat: |
74 | // "watch ls 2>/dev/null" does not detect tty size |
75 | get_terminal_width_height(STDERR_FILENO, &new_width, NULL); |
76 | if (new_width != width) { |
77 | width = new_width; |
78 | free(header); |
79 | header = xasprintf("Every %us: %-*s", period, (int)width, cmd); |
80 | } |
81 | if (time_len < width) { |
82 | strftime_YYYYMMDDHHMMSS( |
83 | header + width - time_len, |
84 | time_len, |
85 | /*time_t*:*/ NULL |
86 | ); |
87 | } |
88 | |
89 | // compat: empty line between header and cmd output |
90 | printf("%s\n\n", header); |
91 | } |
92 | fflush_all(); |
93 | // TODO: 'real' watch pipes cmd's output to itself |
94 | // and does not allow it to overflow the screen |
95 | // (taking into account linewrap!) |
96 | system(cmd); |
97 | sleep(period); |
98 | } |
99 | return 0; // gcc thinks we can reach this :) |
100 | } |
101 |