#!/usr/bin/perl -w
# Copyright © 2005-2019 Jamie Zawinski <jwz@jwz.org>
#
# Permission to use, copy, modify, distribute, and sell this software and its
# documentation for any purpose is hereby granted without fee, provided that
# the above copyright notice appear in all copies and that both that
# copyright notice and this permission notice appear in supporting
# documentation. No representations are made about the suitability of this
# software for any purpose. It is provided "as is" without express or
# implied warranty.
#
# This program writes some text to stdout, based on preferences in the
# .xscreensaver file. It may load a file, a URL, run a program, or just
# print the date.
#
# In a native MacOS build of xscreensaver, this script is included in
# the Contents/Resources/ directory of each screen saver .bundle that
# uses it; and in that case, it looks up its resources using
# /usr/bin/defaults instead.
#
# Created: 19-Mar-2005.
require 5;
#use diagnostics; # Fails on some MacOS 10.5 systems
use strict;
# Some Linux systems don't install LWP by default!
# Only error out if we're actually loading a URL instead of local data.
BEGIN { eval 'use LWP::UserAgent;' }
# Not sure how prevalent this is. Hope it's part of the default install.
BEGIN { eval 'use HTML::Entities;' }
use Socket;
use POSIX qw(strftime);
use Text::Wrap qw(wrap);
#use bytes; # This breaks shit.
my $progname = $0; $progname =~ s@.*/@@g;
my ($version) = ('$Revision: 1.48 $' =~ m/\s(\d[.\d]+)\s/s);
my $verbose = 0;
my $http_proxy = undef;
my $config_file = $ENV{HOME} . "/.xscreensaver";
my $text_mode = 'date';
my $text_literal = '';
my $text_file = '';
my $text_program = '';
my $text_url = 'https://en.wikipedia.org/w/index.php?title=Special:NewPages&feed=rss';
# Default URL needs to be set and match what's in OSX/XScreenSaverView.m
my $wrap_columns = undef;
my $truncate_lines = undef;
my $latin1_p = 0;
my $nyarlathotep_p = 0;
# Convert any HTML entities to Latin1 characters.
#
sub de_entify($) {
my ($text) = @_;
return '' unless defined($text);
return $text unless ($text =~ m/&/s);
# Convert any HTML entities to Unicode characters,
# if the HTML::Entities module is installed.
eval {
my $t2 = $text;
$text = undef;
$text = HTML::Entities::decode_entities ($t2);
};
return $text if defined($text);
# If it's not installed, just complain instead of trying to halfass it.
print STDOUT ("\n\tPerl is broken. Do this to repair it:\n" .
"\n\tsudo cpan HTML::Entities\n\n");
exit (1);
}
# Convert any Unicode characters to Latin1 if possible.
# Unconvertable bytes are left alone.
#
sub utf8_to_latin1($) {
my ($text) = @_;
utf8::encode ($text); # Unpack Unicode back to multi-byte UTF-8.
# Maybe it would be better to handle this in the Unicode domain
# by doing things like s/\x{2018}/\"/g, but without decoding the
# string back to UTF-8 first, I'm at a loss as to how to have
# "á" print as "\340" instead of as "\303\240".
$text =~ s/ \xC2 ( [\xA0-\xFF] ) / $1 /gsex;
$text =~ s/ \xC3 ( [\x80-\xFF] ) / chr (ord($1) | 0x40) /gsex;
# Handles a few 3-byte sequences too.
$text =~ s/\xE2\x80\x93/--/gs;
$text =~ s/\xE2\x80\x94/--/gs;
$text =~ s/\xE2\x80\x98/`/gs;
$text =~ s/\xE2\x80\x99/'/gs;
$text =~ s/\xE2\x80\x9C/``/gs;
$text =~ s/\xE2\x80\x9D/'/gs;
$text =~ s/\xE2\x80\xA2/•/gs;
$text =~ s/\xE2\x80\xA6/.../gs;
$text =~ s/\xE2\x80\xB2/'/gs;
$text =~ s/\xE2\x84\xA2/™/gs;
$text =~ s/\xE2\x86\x90/ ← /gs;
return $text;
}
# Reads the prefs we use from ~/.xscreensaver
#
sub get_x11_prefs() {
my $got_any_p = 0;
if (open (my $in, '<', $config_file)) {
print STDERR "$progname: reading $config_file\n" if ($verbose > 1);
local $/ = undef; # read entire file
my $body = <$in>;
close $in;
$got_any_p = get_x11_prefs_1 ($body);
} elsif ($verbose > 1) {
print STDERR "$progname: $config_file: $!\n";
}
if (! $got_any_p && defined ($ENV{DISPLAY})) {
# We weren't able to read settings from the .xscreensaver file.
# Fall back to any settings in the X resource database
# (/usr/X11R6/lib/X11/app-defaults/XScreenSaver)
#
print STDERR "$progname: reading X resources\n" if ($verbose > 1);
my $body = `appres XScreenSaver xscreensaver -1`;
$got_any_p = get_x11_prefs_1 ($body);
}
if ($verbose > 1) {
print STDERR "$progname: mode: $text_mode\n";
print STDERR "$progname: literal: $text_literal\n";
print STDERR "$progname: file: $text_file\n";
print STDERR "$progname: program: $text_program\n";
print STDERR "$progname: url: $text_url\n";
}
$text_mode =~ tr/A-Z/a-z/;
$text_literal =~ s@\\n@\n@gs;
$text_literal =~ s@\\\n@\n@gs;
}
sub get_x11_prefs_1($) {
my ($body) = @_;
my $got_any_p = 0;
$body =~ s@\\\n@@gs;
$body =~ s@^[ \t]*#[^\n]*$@@gm;
if ($body =~ m/^[.*]*textMode:[ \t]*([^\s]+)\s*$/im) {
$text_mode = $1;
$got_any_p = 1;
}
if ($body =~ m/^[.*]*textLiteral:[ \t]*(.*?)[ \t]*$/im) {
$text_literal = $1;
}
if ($body =~ m/^[.*]*textFile:[ \t]*(.*?)[ \t]*$/im) {
$text_file = $1;
}
if ($body =~ m/^[.*]*textProgram:[ \t]*(.*?)[ \t]*$/im) {
$text_program = $1;
}
if ($body =~ m/^[.*]*textURL:[ \t]*(.*?)[ \t]*$/im) {
$text_url = $1;
}
return $got_any_p;
}
sub get_cocoa_prefs($) {
my ($id) = @_;
my $v;
print STDERR "$progname: reading Cocoa prefs: \"$id\"\n" if ($verbose > 1);
$v = get_cocoa_pref_1 ($id, "textMode");
$text_mode = $v if defined ($v);
# The "textMode" pref is set to a number instead of a string because I
# couldn't figure out the black magic to make Cocoa bindings work right.
#
# Update: as of 5.33, Cocoa writes strings instead of numbers, but
# pre-existing saved preferences might still have numbers in them.
#
if ($text_mode eq '0') { $text_mode = 'date'; }
elsif ($text_mode eq '1') { $text_mode = 'literal'; }
elsif ($text_mode eq '2') { $text_mode = 'file'; }
elsif ($text_mode eq '3') { $text_mode = 'url'; }
elsif ($text_mode eq '4') { $text_mode = 'program'; }
$v = get_cocoa_pref_1 ($id, "textLiteral");
$text_literal = $v if defined ($v);
$text_literal =~ s@\\n@\n@gs;
$text_literal =~ s@\\\n@\n@gs;
$v = get_cocoa_pref_1 ($id, "textFile");
$text_file = $v if defined ($v);
$v = get_cocoa_pref_1 ($id, "textProgram");
$text_program = $v if defined ($v);
$v = get_cocoa_pref_1 ($id, "textURL");
$text_url = $v if defined ($v);
}
sub get_cocoa_pref_1($$) {
my ($id, $key) = @_;
# make sure there's nothing stupid/malicious in either string.
$id =~ s/[^-a-z\d. ]/_/gsi;
$key =~ s/[^-a-z\d. ]/_/gsi;
my $cmd = "defaults -currentHost read \"$id\" \"$key\"";
print STDERR "$progname: executing $cmd\n"
if ($verbose > 3);
my $val = `$cmd 2>/dev/null`;
$val =~ s/^\s+//s;
$val =~ s/\s+$//s;
print STDERR "$progname: Cocoa: $id $key = \"$val\"\n"
if ($verbose > 2);
$val = undef if ($val =~ m/^$/s);
return $val;
}
# like system() but checks errors.
#
sub safe_system(@) {
my (@cmd) = @_;
print STDERR "$progname: executing " . join(' ', @cmd) . "\n"
if ($verbose > 3);
system @cmd;
my $exit_value = $? >> 8;
my $signal_num = $? & 127;
my $dumped_core = $? & 128;
error ("$cmd[0]: core dumped!") if ($dumped_core);
error ("$cmd[0]: signal $signal_num!") if ($signal_num);
error ("$cmd[0]: exited with $exit_value!") if ($exit_value);
}
sub which($) {
my ($cmd) = @_;
if ($cmd =~ m@^\./|^/@) {
error ("cannot execute $cmd") unless (-x $cmd);
return $cmd;
}
foreach my $dir (split (/:/, $ENV{PATH})) {
my $cmd2 = "$dir/$cmd";
print STDERR "$progname: checking $cmd2\n" if ($verbose > 3);
return $cmd2 if (-x "$cmd2");
}
error ("$cmd not found on \$PATH");
}
sub output() {
binmode (STDOUT, ($latin1_p ? ':raw' : ':utf8'));
binmode (STDERR, ':utf8');
# Do some basic sanity checking (null text, null file names, etc.)
#
if (($text_mode eq 'literal' && $text_literal =~ m/^\s*$/i) ||
($text_mode eq 'file' && $text_file =~ m/^\s*$/i) ||
($text_mode eq 'program' && $text_program =~ m/^\s*$/i) ||
($text_mode eq 'url' && $text_url =~ m/^\s*$/i)) {
print STDERR "$progname: falling back to 'date'\n" if ($verbose);
$text_mode = 'date';
}
if ($text_mode eq 'literal') {
$text_literal = strftime ($text_literal, localtime);
$text_literal = utf8_to_latin1($text_literal) if ($latin1_p);
$text_literal =~ y/A-Za-z/N-ZA-Mn-za-m/ if ($nyarlathotep_p);
print STDOUT $text_literal;
print STDOUT "\n" unless ($text_literal =~ m/\n$/s);
} elsif ($text_mode eq 'file') {
$text_file =~ s@^~/@$ENV{HOME}/@s; # allow literal "~/"
if (open (my $in, '<:raw', $text_file)) {
print STDERR "$progname: reading $text_file\n" if ($verbose);
binmode (STDOUT, ':raw');
if (($wrap_columns && $wrap_columns > 0) || $truncate_lines) {
# read it, then reformat it.
local $/ = undef; # read entire file
my $body = <$in>;
$body = reformat_text ($body);
print STDOUT $body;
} else {
# stream it by lines
while (<$in>) {
$_ = utf8_to_latin1($_) if ($latin1_p);
y/A-Za-z/N-ZA-Mn-za-m/ if ($nyarlathotep_p);
print STDOUT $_;
}
}
close $in;
} else {
error ("$text_file: $!");
}
} elsif ($text_mode eq 'program') {
my ($prog, $args) = ($text_program =~ m/^([^\s]+)(.*)$/);
$text_program = which ($prog) . $args;
print STDERR "$progname: running $text_program\n" if ($verbose);
if (($wrap_columns && $wrap_columns > 0) || $truncate_lines) {
# read it, then reformat it.
my $lines = 0;
my $body = "";
my $cmd = "( $text_program ) 2>&1";
# $cmd .= " | sed -l"; # line buffer instead of 4k pipe buffer
open (my $pipe, '-|:unix', $cmd);
while (my $line = <$pipe>) {
$body .= $line;
$lines++;
last if ($truncate_lines && $lines > $truncate_lines);
}
close $pipe;
# I don't understand why we must do this here, but must not do this
# in the 'file' branch above, which reads the file with :raw...
utf8::decode ($body); # Pack multi-byte UTF-8 back into wide chars.
$body = reformat_text ($body);
print STDOUT $body;
} else {
# stream it
safe_system ("$text_program");
}
} elsif ($text_mode eq 'url') {
get_url_text ($text_url);
} else { # $text_mode eq 'date'
my $n = `uname -n`;
$n =~ s/\.local\n/\n/s;
print $n;
my $unamep = 1;
if (-f "/etc/redhat-release") { # "Fedora Core release 4 (Stentz)"
safe_system ("cat", "/etc/redhat-release");
}
if (-f "/etc/release") { # "Solaris 10 3/05 s10_74L2a X86"
safe_system ("head", "-1", "/etc/release");
}
if (-f "/usr/sbin/system_profiler") { # "Mac OS X 10.4.5 (8H14)"
my $sp = # "iMac G5"
`/usr/sbin/system_profiler SPSoftwareDataType SPHardwareDataType 2>/dev/null`;
# system_profiler on OS X 10.10 generates spurious error messages.
my ($v) = ($sp =~ m/^\s*System Version:\s*(.*)$/mi);
my ($s) = ($sp =~ m/^\s*(?:CPU|Processor) Speed:\s*(.*)$/mi);
my ($t) = ($sp =~ m/^\s*(?:Machine|Model) Name:\s*(.*)$/mi);
print "$v\n" if ($v);
print "$s $t\n" if ($s && $t);
$unamep = !defined ($v);
}
if ($unamep) {
safe_system ("uname", "-sr"); # "Linux 2.6.15-1.1831_FC4"
}
print "\n";
safe_system ("date", "+%c");
print "\n";
my $ut = `uptime`;
$ut =~ s/^[ \d:]*(am|pm)?//i;
$ut =~ s/,\s*(load)/\n$1/;
print "$ut\n";
}
}
# Make an educated guess as to what's in this document.
# We don't necessarily take the Content-Type header at face value.
# Returns 'html', 'rss', or 'text';
#
sub guess_content_type($$) {
my ($ct, $body) = @_;
$body =~ s/^(.{512}).*/$1/s; # only look in first half K of file
if ($ct =~ m@^text/.*html@i) { return 'html'; }
if ($ct =~ m@\b(atom|rss|xml)\b@i) { return 'rss'; }
if ($body =~ m@^\s*<\?xml@is) { return 'rss'; }
if ($body =~ m@^\s*<!DOCTYPE RSS@is) { return 'rss'; }
if ($body =~ m@^\s*<!DOCTYPE HTML@is) { return 'html'; }
if ($body =~ m@<(BASE|HTML|HEAD|BODY|SCRIPT|STYLE|TABLE|A\s+HREF)\b@i) {
return 'html';
}
if ($body =~ m@<(RSS|CHANNEL|GENERATOR|DESCRIPTION|CONTENT|FEED|ENTRY)\b@i) {
return 'rss';
}
return 'text';
}
sub reformat_html($$) {
my ($body, $rss_p) = @_;
$_ = $body;
# In HTML, try to preserve newlines inside of PRE.
#
if (! $rss_p) {
s@(<PRE\b[^<>]*>\s*)(.*?)(</PRE)@{
my ($a, $b, $c) = ($1, $2, $3);
$b =~ s/[\r\n]/<BR>/gs;
$a . $b . $c;
}@gsexi;
}
if (! $rss_p) {
# In HTML, unfold lines.
# In RSS, assume \n means literal line break.
s@[\r\n]@ @gsi;
}
# This right here is the part where I doom us all to inhuman
# toil for the One whose Name cannot be expressed in the
# Basic Multilingual Plane. http://jwz.org/b/yhAT He comes.
s@<!--.*?-->@@gsi; # lose comments
s@<(STYLE|SCRIPT)\b[^<>]*>.*?</\1\s*>@@gsi; # lose css and js
s@</?(BR|TR|TD|LI|DIV)\b[^<>]*>@\n@gsi; # line break at BR, TD, DIV, etc
s@</?(P|UL|OL|BLOCKQUOTE)\b[^<>]*>@\n\n@gsi; # two line breaks
s@<lj\s+user=\"?([^<>\"]+)\"?[^<>]*>?@$1@gsi; # handle <LJ USER=>
s@</?[BI]>@*@gsi; # bold, italic => asterisks
s@<[^<>]*>?@@gs; # lose all other HTML tags
$_ = de_entify ($_); # convert HTML entities
# For Wikipedia: delete anything inside {{ }} and unwrap [[tags]],
# among other things.
#
if ($rss_p eq 'wiki') {
s@<!--.*?-->@@gsi; # lose HTML comments again
# Creation line is often truncated: screws up parsing with unbalanced {{.
s@(: +[^a-zA-Z ]* *Created page) with [^\n]+@$1@s;
s@/\*.*?\*/@@si; # /* ... */
# Try to omit all tables, since they're impossible to read as text.
#
1 while (s/\{\{[^{}]*}}/ /gs); # {{ ... }}
1 while (s/\{\|.*?\|\}/\n\n/gs); # {| ... |}
1 while (s/\|-.*?\|/ /gs); # |- ... | (table cell)
# Convert anchors to something more readable.
#
s/\[\[([^\[\]\|]+)\|([^\[\]]+)\]\]/$2/gs; # [[link|anchor]]
s/\[\[([^:\[\]\|]+)\]\]/$1/gs; # [[anchor]]
s/\[https?:[^\[\]\s]+\s+([^\[\]]+)\]/$1/gs; # [url anchor]
# Convert all references to asterisks.
s@\s*<ref>\s*.*?</ref>@*@gs; # <ref> ... <ref> -> "*"
s@\n[ \t]*\d+\s*\^\s*http[^\s]+[ \t]*\n@\n@gs; # 1 ^ URL (a Reflist)
s@\[\[File:([^\|\]]+).*?\]\]@\n$1\n@gs; # [[File: X | ... ]]
s@\[\[Category:.*?\]\]@@gs; # omit categories
s/<[^<>]*>//gs; # Omit all remaining tags
s/\'{3,}//gs; # Omit ''' and ''''
s/\'\'/\"/gs; # '' -> "
s/\`\`/\"/gs; # `` -> "
s/\"\"+/\"/gs; # "" -> "
s/^[ \t]*[*#]+[ \t]*$//gm; # Omit lines with just * or # on them
# Omit trailing headlines with no text after them (e.g. == Notes ==)
1 while (s/\n==+[ \t]*[^\n=]+[ \t]*==+\s*$/\n/s);
$_ = de_entify ($_); # convert HTML entities, again
}
# elide any remaining non-Latin1 binary data.
if ($latin1_p) {
utf8::encode ($_); # Unpack Unicode back to multi-byte UTF-8.
s/([^\000-\176]+(\s*[^\000-\176]+)[^a-z\d]*)/\xAB...\xBB /g;
}
$_ .= "\n";
s/[ \t]+$//gm; # lose whitespace at end of line
s@\n\n\n+@\n\n@gs; # compress blank lines
if (!defined($wrap_columns) || $wrap_columns > 0) {
$Text::Wrap::columns = ($wrap_columns || 72);
$Text::Wrap::break = '[\s/|]'; # wrap on slashes for URLs
$_ = wrap ("", " ", $_); # wrap the lines as a paragraph
s/[ \t]+$//gm; # lose whitespace at end of line again
}
s/^\n+//gs;
if ($truncate_lines) {
s/^(([^\n]*\n){$truncate_lines}).*$/$1/s;
}
$_ = utf8_to_latin1($_) if ($latin1_p);
y/A-Za-z/N-ZA-Mn-za-m/ if ($nyarlathotep_p);
return $_;
}
sub reformat_rss($) {
my ($body) = @_;
my $wiki_p = ($body =~ m@<generator>[^<>]*Wiki@si);
$body =~ s/(<(ITEM|ENTRY)\b)/\001\001$1/gsi;
my @items = split (/\001\001/, $body);
print STDERR "$progname: converting RSS ($#items items)...\n"
if ($verbose > 2);
shift @items;
# Let's skip forward in the stream by a random amount, so that if
# two copies of ljlatest are running at the same time (e.g., on a
# multi-headed machine), they get different text. (Put the items
# that we take off the front back on the back.)
#
if ($#items > 7) {
my $n = int (rand ($#items - 5));
print STDERR "$progname: rotating by $n items...\n" if ($verbose > 2);
while ($n-- > 0) {
push @items, (shift @items);
}
}
my $out = '';
my $i = -1;
foreach (@items) {
$i++;
my ($title, $author, $body1, $body2, $body3);
$title = $3 if (m@<((TITLE) [^<>\s]*)[^<>]*>\s*(.*?)\s*</\1>@xsi);
$author= $3 if (m@<((DC:CREATOR) [^<>\s]*)[^<>]*>\s*(.*?)\s*</\1>@xsi);
$body1 = $3 if (m@<((DESCRIPTION) [^<>\s]*)[^<>]*>\s*(.*?)\s*</\1>@xsi);
$body2 = $3 if (m@<((CONTENT) [^<>\s]*)[^<>]*>\s*(.*?)\s*</\1>@xsi);
$body3 = $3 if (m@<((SUMMARY) [^<>\s]*)[^<>]*>\s*(.*?)\s*</\1>@xsi);
# If there are both <description> and <content> or <content:encoded>,
# use whichever one contains more text.
#
if ($body3 && length($body3) >= length($body2 || '')) {
$body2 = $body3;
}
if ($body2 && length($body2) >= length($body1 || '')) {
$body1 = $body2;
}
if (! $body1) {
if ($title) {
print STDERR "$progname: no body in item $i (\"$title\")\n"
if ($verbose > 2);
} else {
print STDERR "$progname: no body or title in item $i\n"
if ($verbose > 2);
next;
}
}
$title = rss_field_to_html ($title || '');
$author= rss_field_to_html ($author || '');
$body1 = rss_field_to_html ($body1 || '');
$title = '' if ($body1 eq $title); # Identical in Twitter's atom feed.
# Omit author if it's in the title or body
$author = '' if ($author &&
($title =~ m/\Q$author\E/si ||
$body1 =~ m/\Q$author\E/si));
$title = $author if ($author && !$title);
$title = "$author: $title" if ($author && $title);
$out .= reformat_html ("$title<P>$body1", $wiki_p ? 'wiki' : 'rss');
$out .= "\n";
}
if ($truncate_lines) {
$out =~ s/^(([^\n]*\n){$truncate_lines}).*$/$1/s;
}
return $out;
}
sub rss_field_to_html($) {
my ($body) = @_;
# If <![CDATA[...]]> is present, everything inside that is HTML,
# and not double-encoded.
#
if ($body =~ m/^\s*<!\[CDATA\[(.*?)\]\s*\]/is) {
$body = $1;
} else {
$body = de_entify ($body); # convert entities to get HTML from XML
}
return $body;
}
sub reformat_text($) {
my ($body) = @_;
# only re-wrap if --cols was specified. Otherwise, dump it as is.
#
if ($wrap_columns && $wrap_columns > 0) {
print STDERR "$progname: wrapping at $wrap_columns...\n" if ($verbose > 2);
$Text::Wrap::columns = $wrap_columns;
$Text::Wrap::break = '[\s/]'; # wrap on slashes for URLs
$body = wrap ("", "", $body);
$body =~ s/[ \t]+$//gm;
}
if ($truncate_lines) {
$body =~ s/^(([^\n]*\n){$truncate_lines}).*$/$1/s;
}
$body = utf8_to_latin1($body) if ($latin1_p);
$body =~ y/A-Za-z/N-ZA-Mn-za-m/ if ($nyarlathotep_p);
return $body;
}
# Figure out what the proxy server should be, either from environment
# variables or by parsing the output of the (MacOS) program "scutil",
# which tells us what the system-wide proxy settings are.
#
sub set_proxy($) {
my ($ua) = @_;
my $proxy_data = `scutil --proxy 2>/dev/null`;
foreach my $proto ('http', 'https') {
my ($server) = ($proxy_data =~ m/\b${proto}Proxy\s*:\s*([^\s]+)/si);
my ($port) = ($proxy_data =~ m/\b${proto}Port\s*:\s*([^\s]+)/si);
my ($enable) = ($proxy_data =~ m/\b${proto}Enable\s*:\s*([^\s]+)/si);
if ($server && $enable) {
# Note: this ignores the "ExceptionsList".
my $proto2 = 'http';
$ENV{"${proto}_proxy"} = ("${proto2}://" . $server .
($port ? ":$port" : "") . "/");
print STDERR "$progname: MacOS $proto proxy: " .
$ENV{"${proto}_proxy"} . "\n"
if ($verbose > 2);
}
}
$ua->env_proxy();
}
sub get_url_text($) {
my ($url) = @_;
my $ua = eval 'LWP::UserAgent->new';
if (! $ua) {
print STDOUT ("\n\tPerl is broken. Do this to repair it:\n" .
"\n\tsudo cpan LWP::UserAgent" .
" LWP::Protocol::https Mozilla::CA\n\n");
return;
}
# Half the time, random Linux systems don't have Mozilla::CA installed,
# which results in "Can't verify SSL peers without knowning which
# Certificate Authorities to trust".
#
# I'm going to take a controversial stand here and say that, for the
# purposes of plain-text being displayed in a screen saver via RSS,
# the chances of a certificate-based man-in-the-middle attack having
# a malicious effect on anyone anywhere at any time is so close to
# zero that it can be discounted. So, just don't bother validating
# SSL connections.
#
$ENV{'PERL_LWP_SSL_VERIFY_HOSTNAME'} = 0;
eval {
$ua->ssl_opts (verify_hostname => 0, SSL_verify_mode => 0);
};
set_proxy ($ua);
$ua->agent ("$progname/$version");
my $res = $ua->get ($url);
my $body;
my $ct;
if ($res && $res->is_success) {
$body = $res->decoded_content || '';
$ct = $res->header ('Content-Type') || 'text/plain';
} else {
my $err = ($res ? $res->status_line : '') || '';
$err = 'unknown error' unless $err;
$err = "$url: $err";
# error ($err);
$body = "Error loading URL $err\n\n";
$ct = 'text/plain';
}
# This is not necessary, since HTTP::Message::decoded_content() has
# already done 'decode (<charset-header>, $body)'.
# utf8::decode ($body); # Pack multi-byte UTF-8 back into wide chars.
$ct = guess_content_type ($ct, $body);
if ($ct eq 'html') {
print STDERR "$progname: converting HTML...\n" if ($verbose > 2);
$body = reformat_html ($body, 0);
} elsif ($ct eq 'rss') {
$body = reformat_rss ($body);
} else {
print STDERR "$progname: plain text...\n" if ($verbose > 2);
$body = reformat_text ($body);
}
print STDOUT $body;
}
sub error($) {
my ($err) = @_;
print STDERR "$progname: $err\n";
exit 1;
}
sub usage() {
print STDERR "usage: $progname [ --options ... ]\n" .
("\n" .
" Prints out some text for use by various screensavers,\n" .
" according to the options in the ~/.xscreensaver file.\n" .
" This may dump the contents of a file, run a program,\n" .
" or load a URL.\n".
"\n" .
" Options:\n" .
"\n" .
" --date Print the host name and current time.\n" .
"\n" .
" --text STRING Print out the given text. It may contain %\n" .
" escape sequences as per strftime(2).\n" .
"\n" .
" --file PATH Print the contents of the given file.\n" .
" If --cols is specified, re-wrap the lines;\n" .
" otherwise, print them as-is.\n" .
"\n" .
" --program CMD Run the given program and print its output.\n" .
" If --cols is specified, re-wrap the output.\n" .
"\n" .
" --url HTTP-URL Download and print the contents of the HTTP\n" .
" document. If it contains HTML, RSS, or Atom,\n" .
" it will be converted to plain-text.\n" .
"\n" .
" --cols N Wrap lines at this column. Default 72.\n" .
"\n" .
" --lines N No more than N lines of output.\n" .
"\n" .
" --latin1 Emit Latin1 instead of UTF-8.\n" .
"\n");
exit 1;
}
sub main() {
my $load_p = 1;
my $cocoa_id = undef;
while ($#ARGV >= 0) {
$_ = shift @ARGV;
if ($_ eq "--verbose") { $verbose++; }
elsif (m/^-v+$/) { $verbose += length($_)-1; }
elsif (m/^--?date$/) { $text_mode = 'date';
$load_p = 0; }
elsif (m/^--?text$/) { $text_mode = 'literal';
$text_literal = shift @ARGV || '';
$text_literal =~ s@\\n@\n@gs;
$text_literal =~ s@\\\n@\n@gs;
$load_p = 0; }
elsif (m/^--?file$/) { $text_mode = 'file';
$text_file = shift @ARGV || '';
$load_p = 0; }
elsif (m/^--?program$/) { $text_mode = 'program';
$text_program = shift @ARGV || '';
$load_p = 0; }
elsif (m/^--?url$/) { $text_mode = 'url';
$text_url = shift @ARGV || '';
$load_p = 0; }
elsif (m/^--?col(umn)?s?$/) { $wrap_columns = 0 + shift @ARGV; }
elsif (m/^--?lines?$/) { $truncate_lines = 0 + shift @ARGV; }
elsif (m/^--?cocoa$/) { $cocoa_id = shift @ARGV; }
elsif (m/^--?latin1$/) { $latin1_p++; }
elsif (m/^--?nyarlathotep$/) { $nyarlathotep_p++; }
elsif (m/^-./) { usage; }
else { usage; }
}
if ($load_p) {
if (!defined ($cocoa_id)) {
# see OSX/XScreenSaverView.m
$cocoa_id = $ENV{XSCREENSAVER_CLASSPATH};
}
if (defined ($cocoa_id)) {
get_cocoa_prefs($cocoa_id);
} else {
get_x11_prefs();
}
}
output();
if (defined ($cocoa_id)) {
#
# On MacOS, sleep for 10 seconds between when the last output is
# printed, and when this process exits. This is because MacOS
# 10.5.0 and later broke ptys in a new and exciting way: basically,
# once the process at the end of the pty exits, you have exactly
# 1 second to read all the queued data off the pipe before it is
# summarily flushed.
#
# Many of the screen savers were written to depend on being able
# to read a small number of bytes, and continue reading until they
# reached EOF. This is no longer possible.
#
# Note that the current MacOS behavior has all four of these
# awesome properties: 1) Inconvenient; 2) Has no sane workaround;
# 3) Different behavior than MacOS 10.1 through 10.4; and 4)
# Different behavior than every other Unix in the world.
#
# See http://jwz.org/b/DHke, and for those of you inside Apple,
# "Problem ID 5606018".
#
# One workaround would be to rewrite the savers to have an
# internal buffer, and always read as much data as possible as
# soon as a pipe has input available. However, that's a lot more
# work, so instead, let's just not exit right away, and hope that
# 10 seconds is enough.
#
# This will solve the problem for invocations of xscreensaver-text
# that produce little output (e.g., date-mode); and won't solve it
# in cases where a large amount of text is generated in a short
# amount of time (e.g., url-mode.)
#
sleep (10);
}
}
main();
exit 0;
