| /* 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 source tree. |
| */ |
| |
| /* BB_AUDIT SUSv3 N/A */ |
| /* BB_AUDIT GNU defects -- only option -n is supported. */ |
| |
| //config:config WATCH |
| //config: bool "watch" |
| //config: default y |
| //config: help |
| //config: watch is used to execute a program periodically, showing |
| //config: output to the screen. |
| |
| //applet:IF_WATCH(APPLET(watch, BB_DIR_BIN, BB_SUID_DROP)) |
| |
| //kbuild:lib-$(CONFIG_WATCH) += watch.o |
| |
| //usage:#define watch_trivial_usage |
| //usage: "[-n SEC] [-t] PROG ARGS" |
| //usage:#define watch_full_usage "\n\n" |
| //usage: "Run PROG periodically\n" |
| //usage: "\n -n Loop period in seconds (default 2)" |
| //usage: "\n -t Don't print header" |
| //usage: |
| //usage:#define watch_example_usage |
| //usage: "$ watch date\n" |
| //usage: "Mon Dec 17 10:31:40 GMT 2000\n" |
| //usage: "Mon Dec 17 10:31:42 GMT 2000\n" |
| //usage: "Mon Dec 17 10:31:44 GMT 2000" |
| |
| #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"; // 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"); |
| |
| // STDERR_FILENO is procps3 compat: |
| // "watch ls 2>/dev/null" does not detect tty size |
| new_width = get_terminal_width(STDERR_FILENO); |
| if (new_width != width) { |
| width = new_width; |
| free(header); |
| header = xasprintf("Every %us: %-*s", period, (int)width, cmd); |
| } |
| if (time_len < width) { |
| strftime_YYYYMMDDHHMMSS( |
| header + width - time_len, |
| time_len, |
| /*time_t*:*/ NULL |
| ); |
| } |
| |
| // 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 :) |
| } |