[1765] | 1 | /* vi: set sw=4 ts=4: */
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| 2 | /*
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| 3 | * Mini watch implementation for busybox
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| 4 | *
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| 5 | * Copyright (C) 2001 by Michael Habermann <mhabermann@gmx.de>
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| 6 | * Copyrigjt (C) Mar 16, 2003 Manuel Novoa III (mjn3@codepoet.org)
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| 7 | *
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[2725] | 8 | * Licensed under GPLv2 or later, see file LICENSE in this source tree.
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[1765] | 9 | */
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| 10 |
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| 11 | /* BB_AUDIT SUSv3 N/A */
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| 12 | /* BB_AUDIT GNU defects -- only option -n is supported. */
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| 13 |
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[3232] | 14 | //usage:#define watch_trivial_usage
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| 15 | //usage: "[-n SEC] [-t] PROG ARGS"
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| 16 | //usage:#define watch_full_usage "\n\n"
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| 17 | //usage: "Run PROG periodically\n"
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| 18 | //usage: "\n -n Loop period in seconds (default 2)"
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| 19 | //usage: "\n -t Don't print header"
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| 20 | //usage:
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| 21 | //usage:#define watch_example_usage
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| 22 | //usage: "$ watch date\n"
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| 23 | //usage: "Mon Dec 17 10:31:40 GMT 2000\n"
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| 24 | //usage: "Mon Dec 17 10:31:42 GMT 2000\n"
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| 25 | //usage: "Mon Dec 17 10:31:44 GMT 2000"
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| 26 |
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[1765] | 27 | #include "libbb.h"
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| 28 |
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| 29 | // procps 2.0.18:
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| 30 | // watch [-d] [-n seconds]
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| 31 | // [--differences[=cumulative]] [--interval=seconds] command
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| 32 | //
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| 33 | // procps-3.2.3:
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| 34 | // watch [-dt] [-n seconds]
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| 35 | // [--differences[=cumulative]] [--interval=seconds] [--no-title] command
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| 36 | //
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| 37 | // (procps 3.x and procps 2.x are forks, not newer/older versions of the same)
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| 38 |
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[2725] | 39 | int watch_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
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| 40 | int watch_main(int argc UNUSED_PARAM, char **argv)
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[1765] | 41 | {
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| 42 | unsigned opt;
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| 43 | unsigned period = 2;
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[2725] | 44 | unsigned width, new_width;
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| 45 | char *header;
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[1765] | 46 | char *cmd;
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| 47 |
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[2725] | 48 | #if 0 // maybe ENABLE_DESKTOP?
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| 49 | // procps3 compat - "echo TEST | watch cat" doesn't show TEST:
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| 50 | close(STDIN_FILENO);
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| 51 | xopen("/dev/null", O_RDONLY);
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| 52 | #endif
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| 53 |
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| 54 | opt_complementary = "-1:n+"; // at least one param; -n NUM
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| 55 | // "+": stop at first non-option (procps 3.x only)
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| 56 | opt = getopt32(argv, "+dtn:", &period);
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[1765] | 57 | argv += optind;
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| 58 |
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[2725] | 59 | // watch from both procps 2.x and 3.x does concatenation. Example:
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| 60 | // watch ls -l "a /tmp" "2>&1" - ls won't see "a /tmp" as one param
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| 61 | cmd = *argv;
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| 62 | while (*++argv)
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| 63 | cmd = xasprintf("%s %s", cmd, *argv); // leaks cmd
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[1765] | 64 |
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[2725] | 65 | width = (unsigned)-1; // make sure first time new_width != width
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| 66 | header = NULL;
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[1765] | 67 | while (1) {
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[2725] | 68 | /* home; clear to the end of screen */
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| 69 | printf("\033[H""\033[J");
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[1765] | 70 | if (!(opt & 0x2)) { // no -t
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[2725] | 71 | const unsigned time_len = sizeof("1234-67-90 23:56:89");
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[1765] | 72 | time_t t;
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| 73 |
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[2725] | 74 | // STDERR_FILENO is procps3 compat:
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| 75 | // "watch ls 2>/dev/null" does not detect tty size
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| 76 | get_terminal_width_height(STDERR_FILENO, &new_width, NULL);
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| 77 | if (new_width != width) {
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| 78 | width = new_width;
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| 79 | free(header);
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| 80 | header = xasprintf("Every %us: %-*s", period, (int)width, cmd);
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| 81 | }
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[1765] | 82 | time(&t);
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[2725] | 83 | if (time_len < width)
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| 84 | strftime(header + width - time_len, time_len,
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| 85 | "%Y-%m-%d %H:%M:%S", localtime(&t));
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| 86 |
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| 87 | // compat: empty line between header and cmd output
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| 88 | printf("%s\n\n", header);
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[1765] | 89 | }
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[2725] | 90 | fflush_all();
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[1765] | 91 | // TODO: 'real' watch pipes cmd's output to itself
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| 92 | // and does not allow it to overflow the screen
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| 93 | // (taking into account linewrap!)
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| 94 | system(cmd);
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| 95 | sleep(period);
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| 96 | }
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| 97 | return 0; // gcc thinks we can reach this :)
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| 98 | }
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