343 lines
8.3 KiB
Perl
Executable File
343 lines
8.3 KiB
Perl
Executable File
#!/usr/bin/perl -w
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# tail.pl - an example client for LCDproc
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#
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# This client for LCDproc displays the tail of a specified file.
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# It's possible to change the visible part of the file with LCDproc
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# controlled keys
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#
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#
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# Copyright (c) 1999, William Ferrell, Scott Scriven
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# 2001, David Glaude
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# 2001, Jarda Benkovsky
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# 2002, Jonathan Oxer
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# 2002, Rene Wagner <reenoo@gmx.de>
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# 2008, Peter Marschall
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#
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# This file is free software; you can redistribute it and/or modify
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# it under the terms of the GNU General Public License as published by
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# the Free Software Foundation; either version 2 of the License, or
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# any later version.
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#
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# This file is distributed in the hope that it will be useful,
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# but WITHOUT ANY WARRANTY; without even the implied warranty of
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# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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# GNU General Public License for more details.
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#
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# You should have received a copy of the GNU General Public License
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# along with this file; if not, write to the Free Software
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# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301
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#
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use 5.005;
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use strict;
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use Getopt::Std;
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use IO::Socket;
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use Fcntl;
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############################################################
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# Configurable part. Set it according your setup.
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############################################################
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# Host which runs LCDproc daemon (LCDd)
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my $SERVER = "localhost";
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# Port on which LCDd listens to requests
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my $PORT = "13666";
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############################################################
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# End of user configurable parts
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############################################################
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# These define the visible part of the file...
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my $top = 3; # How far from the end of the file should we start by default?
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my $lines = 3; # How many lines to display by default ?
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my $left = 1; # Left/right scrolling position,
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my $width = 20; # and number of characters per line to show
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my $progname = $0;
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$progname =~ s#.*/(.*?)$#$1#;
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# declare functions
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sub error($@);
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sub usage($);
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## main routine ##
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my %opt = ();
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# get options #
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if (getopts('F:s:p:hV', \%opt) == 0) {
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usage(1);
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}
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# check options
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usage(0) if ($opt{h});
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if ($opt{V}) {
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print STDERR $progname ." version 1.1\n";
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exit(0);
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}
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# check number of arguments
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usage(1) if ($#ARGV != 0);
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# set variables
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$SERVER = defined($opt{s}) ? $opt{s} : $SERVER;
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$PORT = defined($opt{p}) ? $opt{p} : $PORT;
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my $filename = shift @ARGV;
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my $slow = 1; # Should we pause after the current frame?
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# Connect to the server...
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my $remote = IO::Socket::INET->new(
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Proto => 'tcp',
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PeerAddr => $SERVER,
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PeerPort => $PORT,
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)
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or error(1, "cannot connect to LCDd daemon at $SERVER:$PORT");
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# Make sure our messages get there right away
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$remote->autoflush(1);
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sleep 1; # Give server plenty of time to notice us...
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print $remote "hello\n";
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# Note: it's good practice to listen for a response after a print to the
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# server even if there isn't meant to be one. If you don't, you may find
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# your program crashes after running for a while when the buffers fill up.
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my $lcdresponse = <$remote>;
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#print $lcdresponse;
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# get width & height from server's greet message
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if ($lcdresponse =~ /\bwid\s+(\d+)\b/) {
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$width = 0 + $1;
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}
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if ($lcdresponse =~ /\bhgt\s+(\d+)\b/) {
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$lines = (0 + $1) - 1;
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$top = $lines;
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}
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# Turn off blocking mode...
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fcntl($remote, F_SETFL, O_NONBLOCK);
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# Set up some screen widgets...
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print $remote "client_set name {$progname}\n";
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$lcdresponse = <$remote>;
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print $remote "screen_add tail\n";
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$lcdresponse = <$remote>;
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print $remote "screen_set tail name {Tail $filename}\n";
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$lcdresponse = <$remote>;
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print $remote "widget_add tail title title\n";
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$lcdresponse = <$remote>;
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print $remote "widget_set tail title {Tail: $filename}\n";
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$lcdresponse = <$remote>;
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# create one widget called lineX (x in {1,2,...}) per line
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for (my $i = 1; $i <= $lines; $i++) {
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print $remote "widget_add tail line$i string\n";
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$lcdresponse = <$remote>;
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}
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# NOTE: You have to ask LCDd to send you keys you want to handle
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print $remote "client_add_key Left\n";
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$lcdresponse = <$remote>;
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print $remote "client_add_key Right\n";
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$lcdresponse = <$remote>;
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print $remote "client_add_key Up\n";
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$lcdresponse = <$remote>;
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print $remote "client_add_key Down\n";
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$lcdresponse = <$remote>;
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# Forever, we should do stuff...
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while (1) {
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# Handle input... (spew it to the console)
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# Also, certain keys scroll the display
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while(defined(my $input = <$remote>)) {
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next if ($input =~ /^success$/o);
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#print $input;
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$slow = -10;
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# Make sure we handle each line...
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my @lines = split(/\n/, $input);
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foreach my $line (@lines) {
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if ($line =~ /^key (\S+)/) { # Keypresses are useful.
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my $key = $1;
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if ($key eq 'Down') {
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$top-- if ($top > $lines);
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}
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elsif ($key eq 'Up') {
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$top++;
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}
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elsif ($key eq 'Right') {
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$left++;
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}
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elsif ($key eq 'Left') {
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$left-- if ($left > 1);
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}
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}
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}
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}
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# Now, show what the file contains, if anything...
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if ( -f $filename ) {
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# Grab some text.
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my $right = $left + $width - 1;
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# get the data by calling external programs tail, head & cut
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my $text = `tail -$top $filename | head -$lines | cut -c$left-$right`;
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my @lines = split(/\n/, $text);
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# Now, display that text...
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for (my $i = 0; $i < $lines; $i++) {
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my $j = $i + 1;
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my $k = $i + 2;
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# Avoid blank lines
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my $line = ($#lines < $i) ? " " : $lines[$i];
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$line = " " if ($line =~ /^\s*$/o);
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# expand tabs to spaces
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while ((my $idx = index($line, "\t")) >= 0) {
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use integer; # calculate integers like in C
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my $w = 8 + 8 * ($idx / 8) - $idx;
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my $subst = " " x $w;
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$line =~ s/\t/" " x $w/e;
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}
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# write to the display
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print $remote "widget_set tail line$j 1 $k {$line}\n";
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my $lcdresponse = <$remote>;
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}
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}
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else { # If the file is unreadable, show an error
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print $remote "widget_set tail line1 1 2 {$filename}\n";
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$lcdresponse = <$remote>;
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print $remote "widget_set tail line2 1 3 {doesn't exist.}\n";
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$lcdresponse = <$remote>;
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print $remote "widget_set tail line3 1 4 { }\n";
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$lcdresponse = <$remote>;
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}
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# And wait a little while before we show stuff again.
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if ($slow > 0) { sleep 1; $slow++; }
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elsif ($slow > 4) { sleep 2; $slow++; }
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elsif ($slow > 64) { sleep 4; }
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else { $slow++; }
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# The "slow" thing just lets us have a better response time
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# while the user is pressing keys... But while the user
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# is inactive, it gradually decreases update frequency.
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}
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close ($remote) or error(1, "close() failed");
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exit;
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## print out error message and eventually exit ##
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# Synopsis: error($status, $message)
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sub error($@)
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{
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my $status = shift;
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my @msg = @_;
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print STDERR $progname . ": " . join(" ", @msg) . "\n";
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exit($status) if ($status);
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}
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## print out usage message and exit ##
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# Synopsis: usage($status)
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sub usage($)
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{
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my $status = shift;
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print STDERR "Usage: $progname [<options>] <file>\n";
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if (!$status) {
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print STDERR " where <options> are\n" .
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" -s <server> connect to <server> (default: $SERVER)\n" .
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" -p <port> connect to <port> on <server> (default: $PORT)\n" .
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" -h show this help page\n" .
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" -V display version number\n";
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}
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else {
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print STDERR "For help, type: $progname -h\n";
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}
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exit($status);
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}
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__END__
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=pod
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=head1 NAME
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tail.pl -- show tail of a file on LCD
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=head1 SYNOPSIS
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B<tail.pl>
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[B<-s> I<server>]
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[B<-p> I<port>]
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[B<-h>]
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[B<-V>]
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I<file>
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=head1 DESCRIPTION
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B<tail.pl> is a small example client for LCDd, the LCDproc server.
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It shows the tail of th file given as parameter on the LCD.
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If the LCD supports keys you can use the keys mapped to C<Up>, C<Down>,
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C<Left> and C<Right> to scroll the contents shown on the screen.
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=head1 OPTIONS
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=over 4
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=item B<-s> I<server>
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Connect to the LCDd daemon at host I<server> instead of the default C<localhost>.
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=item B<-p> I<port>
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Use port I<port> when connecting to the LCDd server instead of the default
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LCDd port C<13666>.
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=item B<-h>
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Display a short help page and exit.
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=item B<-V>
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Display tail.pl's version number and exit.
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=back
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=head1 SEE ALSO
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L<tail(1)>,
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L<LCDd(8)>
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=head1 AUTHORS
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tail.pl was written by various members of the LCDproc project team;
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this manual page was written by Peter Marschall.
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=cut
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# EOF
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