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/* 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 tarball for details. */ /* BB_AUDIT SUSv3 N/A */ /* BB_AUDIT GNU defects -- only option -n is supported. */ #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:n+"; // 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"); time_t t; // STDERR_FILENO is procps3 compat: // "watch ls 2>/dev/null" does not detect tty size get_terminal_width_height(STDERR_FILENO, &new_width, NULL); if (new_width != width) { width = new_width; free(header); header = xasprintf("Every %us: %-*s", period, (int)width, cmd); } time(&t); if (time_len < width) strftime(header + width - time_len, time_len, "%Y-%m-%d %H:%M:%S", localtime(&t)); // 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 :) } |