Contents of /tags/mkinitrd-6_5_0/busybox/procps/watch.c
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Fri Jun 3 21:22:00 2011 UTC (13 years, 3 months ago) by niro
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Fri Jun 3 21:22:00 2011 UTC (13 years, 3 months ago) by niro
File MIME type: text/plain
File size: 2496 byte(s)
tagged 'mkinitrd-6_5_0'
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 "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 | #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 | 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 | // watch ls -l "a /tmp" "2>&1" - ls won't see "a /tmp" as one param |
48 | 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 | /* home; clear to the end of screen */ |
56 | printf("\033[H""\033[J"); |
57 | if (!(opt & 0x2)) { // no -t |
58 | const unsigned time_len = sizeof("1234-67-90 23:56:89"); |
59 | time_t t; |
60 | |
61 | // 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 | 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 | // compat: empty line between header and cmd output |
75 | printf("%s\n\n", header); |
76 | } |
77 | fflush_all(); |
78 | // 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 | } |