/* vi: set sw=4 ts=4: */ /* * Mini watch implementation for busybox * * Copyright (C) 2001 by Michael Habermann * Copyrigjt (C) Mar 16, 2003 Manuel Novoa III (mjn3@codepoet.org) * * Licensed under GPLv2 or later, see file LICENSE in this source tree. */ //config:config WATCH //config: bool "watch (5.2 kb)" //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-$(CONFIG_WATCH) += watch.o //usage:#define watch_trivial_usage //usage: "[-n SEC] [-t] PROG ARGS" //usage:#define watch_full_usage "\n\n" //usage: "Run PROG periodically\n" //usage: "\n -n SEC Period (default 2)" //usage: "\n -t Don't print header" //usage: //usage:#define watch_example_usage //usage: "$ 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" /* BB_AUDIT SUSv3 N/A */ /* BB_AUDIT GNU defects -- only option -n is supported. */ #include "libbb.h" #define ESC "\033" // 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) { duration_t period; char *period_str = (char*) "2"; unsigned opt; 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 // "+": stop at first non-option (procps 3.x only); -n NUM // at least one param opt = getopt32(argv, "^+" "dtn:" "\0" "-1", &period_str); 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 period = parse_duration_str(period_str); width = (unsigned)-1; // make sure first time new_width != width header = NULL; while (1) { /* home; clear to the end of screen */ printf(ESC"[H" ESC"[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" " %"IF_FLOAT_DURATION(".1")DURATION_FMT"s:" " %-*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_for_duration(period); } return 0; // gcc thinks we can reach this :) }