busybox/procps/watch.c
Denys Vlasenko 8131eea3dc *: introduce and use ffulsh_all()
function                                             old     new   delta
buffer_fill_and_print                                179     196     +17
fflush_all                                             -       9      +9
spawn                                                 87      92      +5
rtcwake_main                                         455     453      -2
...
alarm_intr                                            93      84      -9
readcmd                                             1072    1062     -10
bb_ask                                               345     333     -12
more_main                                            845     832     -13
flush_stdout_stderr                                   42      23     -19
xfflush_stdout                                        27       -     -27
flush_stderr                                          30       -     -30
------------------------------------------------------------------------------
(add/remove: 1/2 grow/shrink: 2/50 up/down: 31/-397)         Total: -366 bytes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2009-11-02 14:19:51 +01:00

76 lines
2.1 KiB
C

/* 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;
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) {
printf("\033[H\033[J");
if (!(opt & 0x2)) { // no -t
const unsigned time_len = sizeof("1234-67-90 23:56:89");
time_t t;
get_terminal_width_height(STDIN_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));
puts(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 :)
}