xref: /linux/scripts/sphinx-pre-install (revision 37744feebc086908fd89760650f458ab19071750)
1#!/usr/bin/perl
2# SPDX-License-Identifier: GPL-2.0-or-later
3use strict;
4
5# Copyright (c) 2017-2019 Mauro Carvalho Chehab <mchehab@kernel.org>
6#
7
8my $prefix = "./";
9$prefix = "$ENV{'srctree'}/" if ($ENV{'srctree'});
10
11my $conf = $prefix . "Documentation/conf.py";
12my $requirement_file = $prefix . "Documentation/sphinx/requirements.txt";
13my $virtenv_prefix = "sphinx_";
14
15#
16# Static vars
17#
18
19my %missing;
20my $system_release;
21my $need = 0;
22my $optional = 0;
23my $need_symlink = 0;
24my $need_sphinx = 0;
25my $rec_sphinx_upgrade = 0;
26my $install = "";
27my $virtenv_dir = "";
28my $min_version;
29
30#
31# Command line arguments
32#
33
34my $pdf = 1;
35my $virtualenv = 1;
36my $version_check = 0;
37
38#
39# List of required texlive packages on Fedora and OpenSuse
40#
41
42my %texlive = (
43	'amsfonts.sty'       => 'texlive-amsfonts',
44	'amsmath.sty'        => 'texlive-amsmath',
45	'amssymb.sty'        => 'texlive-amsfonts',
46	'amsthm.sty'         => 'texlive-amscls',
47	'anyfontsize.sty'    => 'texlive-anyfontsize',
48	'atbegshi.sty'       => 'texlive-oberdiek',
49	'bm.sty'             => 'texlive-tools',
50	'capt-of.sty'        => 'texlive-capt-of',
51	'cmap.sty'           => 'texlive-cmap',
52	'ecrm1000.tfm'       => 'texlive-ec',
53	'eqparbox.sty'       => 'texlive-eqparbox',
54	'eu1enc.def'         => 'texlive-euenc',
55	'fancybox.sty'       => 'texlive-fancybox',
56	'fancyvrb.sty'       => 'texlive-fancyvrb',
57	'float.sty'          => 'texlive-float',
58	'fncychap.sty'       => 'texlive-fncychap',
59	'footnote.sty'       => 'texlive-mdwtools',
60	'framed.sty'         => 'texlive-framed',
61	'luatex85.sty'       => 'texlive-luatex85',
62	'multirow.sty'       => 'texlive-multirow',
63	'needspace.sty'      => 'texlive-needspace',
64	'palatino.sty'       => 'texlive-psnfss',
65	'parskip.sty'        => 'texlive-parskip',
66	'polyglossia.sty'    => 'texlive-polyglossia',
67	'tabulary.sty'       => 'texlive-tabulary',
68	'threeparttable.sty' => 'texlive-threeparttable',
69	'titlesec.sty'       => 'texlive-titlesec',
70	'ucs.sty'            => 'texlive-ucs',
71	'upquote.sty'        => 'texlive-upquote',
72	'wrapfig.sty'        => 'texlive-wrapfig',
73);
74
75#
76# Subroutines that checks if a feature exists
77#
78
79sub check_missing(%)
80{
81	my %map = %{$_[0]};
82
83	foreach my $prog (sort keys %missing) {
84		my $is_optional = $missing{$prog};
85
86		# At least on some LTS distros like CentOS 7, texlive doesn't
87		# provide all packages we need. When such distros are
88		# detected, we have to disable PDF output.
89		#
90		# So, we need to ignore the packages that distros would
91		# need for LaTeX to work
92		if ($is_optional == 2 && !$pdf) {
93			$optional--;
94			next;
95		}
96
97		if ($is_optional) {
98			print "Warning: better to also install \"$prog\".\n";
99		} else {
100			print "ERROR: please install \"$prog\", otherwise, build won't work.\n";
101		}
102		if (defined($map{$prog})) {
103			$install .= " " . $map{$prog};
104		} else {
105			$install .= " " . $prog;
106		}
107	}
108
109	$install =~ s/^\s//;
110}
111
112sub add_package($$)
113{
114	my $package = shift;
115	my $is_optional = shift;
116
117	$missing{$package} = $is_optional;
118	if ($is_optional) {
119		$optional++;
120	} else {
121		$need++;
122	}
123}
124
125sub check_missing_file($$$)
126{
127	my $files = shift;
128	my $package = shift;
129	my $is_optional = shift;
130
131	for (@$files) {
132		return if(-e $_);
133	}
134
135	add_package($package, $is_optional);
136}
137
138sub findprog($)
139{
140	foreach(split(/:/, $ENV{PATH})) {
141		return "$_/$_[0]" if(-x "$_/$_[0]");
142	}
143}
144
145sub check_program($$)
146{
147	my $prog = shift;
148	my $is_optional = shift;
149
150	return if findprog($prog);
151
152	add_package($prog, $is_optional);
153}
154
155sub check_perl_module($$)
156{
157	my $prog = shift;
158	my $is_optional = shift;
159
160	my $err = system("perl -M$prog -e 1 2>/dev/null /dev/null");
161	return if ($err == 0);
162
163	add_package($prog, $is_optional);
164}
165
166sub check_python_module($$)
167{
168	my $prog = shift;
169	my $is_optional = shift;
170
171	my $err = system("python3 -c 'import $prog' 2>/dev/null /dev/null");
172	return if ($err == 0);
173	my $err = system("python -c 'import $prog' 2>/dev/null /dev/null");
174	return if ($err == 0);
175
176	add_package($prog, $is_optional);
177}
178
179sub check_rpm_missing($$)
180{
181	my @pkgs = @{$_[0]};
182	my $is_optional = $_[1];
183
184	foreach my $prog(@pkgs) {
185		my $err = system("rpm -q '$prog' 2>/dev/null >/dev/null");
186		add_package($prog, $is_optional) if ($err);
187	}
188}
189
190sub check_pacman_missing($$)
191{
192	my @pkgs = @{$_[0]};
193	my $is_optional = $_[1];
194
195	foreach my $prog(@pkgs) {
196		my $err = system("pacman -Q '$prog' 2>/dev/null >/dev/null");
197		add_package($prog, $is_optional) if ($err);
198	}
199}
200
201sub check_missing_tex($)
202{
203	my $is_optional = shift;
204	my $kpsewhich = findprog("kpsewhich");
205
206	foreach my $prog(keys %texlive) {
207		my $package = $texlive{$prog};
208		if (!$kpsewhich) {
209			add_package($package, $is_optional);
210			next;
211		}
212		my $file = qx($kpsewhich $prog);
213		add_package($package, $is_optional) if ($file =~ /^\s*$/);
214	}
215}
216
217sub get_sphinx_fname()
218{
219	my $fname = "sphinx-build";
220	return $fname if findprog($fname);
221
222	$fname = "sphinx-build-3";
223	if (findprog($fname)) {
224		$need_symlink = 1;
225		return $fname;
226	}
227
228	if ($virtualenv) {
229		my $prog = findprog("virtualenv-3");
230		$prog = findprog("virtualenv-3.5") if (!$prog);
231
232		check_program("virtualenv", 0) if (!$prog);
233		$need_sphinx = 1;
234	} else {
235		add_package("python-sphinx", 0);
236	}
237
238	return "";
239}
240
241sub check_sphinx()
242{
243	my $rec_version;
244	my $cur_version;
245
246	open IN, $conf or die "Can't open $conf";
247	while (<IN>) {
248		if (m/^\s*needs_sphinx\s*=\s*[\'\"]([\d\.]+)[\'\"]/) {
249			$min_version=$1;
250			last;
251		}
252	}
253	close IN;
254
255	die "Can't get needs_sphinx version from $conf" if (!$min_version);
256
257	open IN, $requirement_file or die "Can't open $requirement_file";
258	while (<IN>) {
259		if (m/^\s*Sphinx\s*==\s*([\d\.]+)$/) {
260			$rec_version=$1;
261			last;
262		}
263	}
264	close IN;
265
266	die "Can't get recommended sphinx version from $requirement_file" if (!$min_version);
267
268	$virtenv_dir = $virtenv_prefix . $rec_version;
269
270	my $sphinx = get_sphinx_fname();
271	return if ($sphinx eq "");
272
273	open IN, "$sphinx --version 2>&1 |" or die "$sphinx returned an error";
274	while (<IN>) {
275		if (m/^\s*sphinx-build\s+([\d\.]+)(\+\/[\da-f]+)?$/) {
276			$cur_version=$1;
277			last;
278		}
279		# Sphinx 1.2.x uses a different format
280		if (m/^\s*Sphinx.*\s+([\d\.]+)$/) {
281			$cur_version=$1;
282			last;
283		}
284	}
285	close IN;
286
287	die "$sphinx didn't return its version" if (!$cur_version);
288
289	if ($cur_version lt $min_version) {
290		printf "ERROR: Sphinx version is %s. It should be >= %s (recommended >= %s)\n",
291		       $cur_version, $min_version, $rec_version;;
292		$need_sphinx = 1;
293		return;
294	}
295
296	if ($cur_version lt $rec_version) {
297		printf "Sphinx version %s\n", $cur_version;
298		print "Warning: It is recommended at least Sphinx version $rec_version.\n";
299		$rec_sphinx_upgrade = 1;
300		return;
301	}
302
303	# On version check mode, just assume Sphinx has all mandatory deps
304	exit (0) if ($version_check);
305}
306
307#
308# Ancillary subroutines
309#
310
311sub catcheck($)
312{
313  my $res = "";
314  $res = qx(cat $_[0]) if (-r $_[0]);
315  return $res;
316}
317
318sub which($)
319{
320	my $file = shift;
321	my @path = split ":", $ENV{PATH};
322
323	foreach my $dir(@path) {
324		my $name = $dir.'/'.$file;
325		return $name if (-x $name );
326	}
327	return undef;
328}
329
330#
331# Subroutines that check distro-specific hints
332#
333
334sub give_debian_hints()
335{
336	my %map = (
337		"python-sphinx"		=> "python3-sphinx",
338		"sphinx_rtd_theme"	=> "python3-sphinx-rtd-theme",
339		"virtualenv"		=> "virtualenv",
340		"dot"			=> "graphviz",
341		"convert"		=> "imagemagick",
342		"Pod::Usage"		=> "perl-modules",
343		"xelatex"		=> "texlive-xetex",
344		"rsvg-convert"		=> "librsvg2-bin",
345	);
346
347	if ($pdf) {
348		check_missing_file(["/usr/share/fonts/truetype/dejavu/DejaVuSans.ttf"],
349				   "fonts-dejavu", 2);
350
351		check_missing_file(["/usr/share/fonts/noto-cjk/NotoSansCJK-Regular.ttc",
352				   "/usr/share/fonts/opentype/noto/NotoSerifCJK-Regular.ttc"],
353				   "fonts-noto-cjk", 2);
354	}
355
356	check_program("dvipng", 2) if ($pdf);
357	check_missing(\%map);
358
359	return if (!$need && !$optional);
360	printf("You should run:\n\n\tsudo apt-get install $install\n");
361}
362
363sub give_redhat_hints()
364{
365	my %map = (
366		"python-sphinx"		=> "python3-sphinx",
367		"sphinx_rtd_theme"	=> "python3-sphinx_rtd_theme",
368		"virtualenv"		=> "python3-virtualenv",
369		"dot"			=> "graphviz",
370		"convert"		=> "ImageMagick",
371		"Pod::Usage"		=> "perl-Pod-Usage",
372		"xelatex"		=> "texlive-xetex-bin",
373		"rsvg-convert"		=> "librsvg2-tools",
374	);
375
376	my @fedora26_opt_pkgs = (
377		"graphviz-gd",		# Fedora 26: needed for PDF support
378	);
379
380	my @fedora_tex_pkgs = (
381		"texlive-collection-fontsrecommended",
382		"texlive-collection-latex",
383		"texlive-xecjk",
384		"dejavu-sans-fonts",
385		"dejavu-serif-fonts",
386		"dejavu-sans-mono-fonts",
387	);
388
389	#
390	# Checks valid for RHEL/CentOS version 7.x.
391	#
392	my $old = 0;
393	my $rel;
394	$rel = $1 if ($system_release =~ /release\s+(\d+)/);
395
396	if (!($system_release =~ /Fedora/)) {
397		$map{"virtualenv"} = "python-virtualenv";
398
399		if ($rel && $rel < 8) {
400			$old = 1;
401			$pdf = 0;
402
403			printf("Note: texlive packages on RHEL/CENTOS <= 7 are incomplete. Can't support PDF output\n");
404			printf("If you want to build PDF, please read:\n");
405			printf("\thttps://www.systutorials.com/241660/how-to-install-tex-live-on-centos-7-linux/\n");
406		}
407	} else {
408		if ($rel && $rel < 26) {
409			$old = 1;
410		}
411	}
412	if (!$rel) {
413		printf("Couldn't identify release number\n");
414		$old = 1;
415		$pdf = 0;
416	}
417
418	if ($pdf) {
419		check_missing_file(["/usr/share/fonts/google-noto-cjk/NotoSansCJK-Regular.ttc"],
420				   "google-noto-sans-cjk-ttc-fonts", 2);
421	}
422
423	check_rpm_missing(\@fedora26_opt_pkgs, 2) if ($pdf && !$old);
424	check_rpm_missing(\@fedora_tex_pkgs, 2) if ($pdf);
425	check_missing_tex(2) if ($pdf);
426	check_missing(\%map);
427
428	return if (!$need && !$optional);
429
430	if (!$old) {
431		# dnf, for Fedora 18+
432		printf("You should run:\n\n\tsudo dnf install -y $install\n");
433	} else {
434		# yum, for RHEL (and clones) or Fedora version < 18
435		printf("You should run:\n\n\tsudo yum install -y $install\n");
436	}
437}
438
439sub give_opensuse_hints()
440{
441	my %map = (
442		"python-sphinx"		=> "python3-sphinx",
443		"sphinx_rtd_theme"	=> "python3-sphinx_rtd_theme",
444		"virtualenv"		=> "python3-virtualenv",
445		"dot"			=> "graphviz",
446		"convert"		=> "ImageMagick",
447		"Pod::Usage"		=> "perl-Pod-Usage",
448		"xelatex"		=> "texlive-xetex-bin",
449		"rsvg-convert"		=> "rsvg-view",
450	);
451
452	my @suse_tex_pkgs = (
453		"texlive-babel-english",
454		"texlive-caption",
455		"texlive-colortbl",
456		"texlive-courier",
457		"texlive-dvips",
458		"texlive-helvetic",
459		"texlive-makeindex",
460		"texlive-metafont",
461		"texlive-metapost",
462		"texlive-palatino",
463		"texlive-preview",
464		"texlive-times",
465		"texlive-zapfchan",
466		"texlive-zapfding",
467	);
468
469	$map{"latexmk"} = "texlive-latexmk-bin";
470
471	# FIXME: add support for installing CJK fonts
472	#
473	# I tried hard, but was unable to find a way to install
474	# "Noto Sans CJK SC" on openSUSE
475
476	check_rpm_missing(\@suse_tex_pkgs, 2) if ($pdf);
477	check_missing_tex(2) if ($pdf);
478	check_missing(\%map);
479
480	return if (!$need && !$optional);
481	printf("You should run:\n\n\tsudo zypper install --no-recommends $install\n");
482}
483
484sub give_mageia_hints()
485{
486	my %map = (
487		"python-sphinx"		=> "python3-sphinx",
488		"sphinx_rtd_theme"	=> "python3-sphinx_rtd_theme",
489		"virtualenv"		=> "python3-virtualenv",
490		"dot"			=> "graphviz",
491		"convert"		=> "ImageMagick",
492		"Pod::Usage"		=> "perl-Pod-Usage",
493		"xelatex"		=> "texlive",
494		"rsvg-convert"		=> "librsvg2-tools",
495	);
496
497	my @tex_pkgs = (
498		"texlive-fontsextra",
499	);
500
501	$map{"latexmk"} = "texlive-collection-basic";
502
503	if ($pdf) {
504		check_missing_file(["/usr/share/fonts/google-noto-cjk/NotoSansCJK-Regular.ttc"],
505				   "google-noto-sans-cjk-ttc-fonts", 2);
506	}
507
508	check_rpm_missing(\@tex_pkgs, 2) if ($pdf);
509	check_missing(\%map);
510
511	return if (!$need && !$optional);
512	printf("You should run:\n\n\tsudo urpmi $install\n");
513}
514
515sub give_arch_linux_hints()
516{
517	my %map = (
518		"sphinx_rtd_theme"	=> "python-sphinx_rtd_theme",
519		"virtualenv"		=> "python-virtualenv",
520		"dot"			=> "graphviz",
521		"convert"		=> "imagemagick",
522		"xelatex"		=> "texlive-bin",
523		"latexmk"		=> "texlive-core",
524		"rsvg-convert"		=> "extra/librsvg",
525	);
526
527	my @archlinux_tex_pkgs = (
528		"texlive-core",
529		"texlive-latexextra",
530		"ttf-dejavu",
531	);
532	check_pacman_missing(\@archlinux_tex_pkgs, 2) if ($pdf);
533
534	if ($pdf) {
535		check_missing_file(["/usr/share/fonts/noto-cjk/NotoSansCJK-Regular.ttc"],
536				   "noto-fonts-cjk", 2);
537	}
538
539	check_missing(\%map);
540
541	return if (!$need && !$optional);
542	printf("You should run:\n\n\tsudo pacman -S $install\n");
543}
544
545sub give_gentoo_hints()
546{
547	my %map = (
548		"sphinx_rtd_theme"	=> "dev-python/sphinx_rtd_theme",
549		"virtualenv"		=> "dev-python/virtualenv",
550		"dot"			=> "media-gfx/graphviz",
551		"convert"		=> "media-gfx/imagemagick",
552		"xelatex"		=> "dev-texlive/texlive-xetex media-fonts/dejavu",
553		"rsvg-convert"		=> "gnome-base/librsvg",
554	);
555
556	check_missing_file(["/usr/share/fonts/dejavu/DejaVuSans.ttf"],
557			   "media-fonts/dejavu", 2) if ($pdf);
558
559	if ($pdf) {
560		check_missing_file(["/usr/share/fonts/noto-cjk/NotoSansCJKsc-Regular.otf"],
561				   "media-fonts/noto-cjk", 2);
562	}
563
564	check_missing(\%map);
565
566	return if (!$need && !$optional);
567
568	printf("You should run:\n\n");
569
570	my $imagemagick = "media-gfx/imagemagick svg png";
571	my $cairo = "media-gfx/graphviz cairo pdf";
572	my $portage_imagemagick = "/etc/portage/package.use/imagemagick";
573	my $portage_cairo = "/etc/portage/package.use/graphviz";
574
575	if (qx(cat $portage_imagemagick) ne "$imagemagick\n") {
576		printf("\tsudo su -c 'echo \"$imagemagick\" > $portage_imagemagick'\n")
577	}
578	if (qx(cat $portage_cairo) ne  "$cairo\n") {
579		printf("\tsudo su -c 'echo \"$cairo\" > $portage_cairo'\n");
580	}
581
582	printf("\tsudo emerge --ask $install\n");
583
584}
585
586sub check_distros()
587{
588	# Distro-specific hints
589	if ($system_release =~ /Red Hat Enterprise Linux/) {
590		give_redhat_hints;
591		return;
592	}
593	if ($system_release =~ /CentOS/) {
594		give_redhat_hints;
595		return;
596	}
597	if ($system_release =~ /Scientific Linux/) {
598		give_redhat_hints;
599		return;
600	}
601	if ($system_release =~ /Oracle Linux Server/) {
602		give_redhat_hints;
603		return;
604	}
605	if ($system_release =~ /Fedora/) {
606		give_redhat_hints;
607		return;
608	}
609	if ($system_release =~ /Ubuntu/) {
610		give_debian_hints;
611		return;
612	}
613	if ($system_release =~ /Debian/) {
614		give_debian_hints;
615		return;
616	}
617	if ($system_release =~ /openSUSE/) {
618		give_opensuse_hints;
619		return;
620	}
621	if ($system_release =~ /Mageia/) {
622		give_mageia_hints;
623		return;
624	}
625	if ($system_release =~ /Arch Linux/) {
626		give_arch_linux_hints;
627		return;
628	}
629	if ($system_release =~ /Gentoo/) {
630		give_gentoo_hints;
631		return;
632	}
633
634	#
635	# Fall-back to generic hint code for other distros
636	# That's far from ideal, specially for LaTeX dependencies.
637	#
638	my %map = (
639		"sphinx-build" => "sphinx"
640	);
641	check_missing_tex(2) if ($pdf);
642	check_missing(\%map);
643	print "I don't know distro $system_release.\n";
644	print "So, I can't provide you a hint with the install procedure.\n";
645	print "There are likely missing dependencies.\n";
646}
647
648#
649# Common dependencies
650#
651
652sub deactivate_help()
653{
654	printf "\tIf you want to exit the virtualenv, you can use:\n";
655	printf "\tdeactivate\n";
656}
657
658sub check_needs()
659{
660	# Check for needed programs/tools
661	check_sphinx();
662
663	if ($system_release) {
664		print "Detected OS: $system_release.\n\n";
665	} else {
666		print "Unknown OS\n\n";
667	}
668
669	print "To upgrade Sphinx, use:\n\n" if ($rec_sphinx_upgrade);
670
671	# Check for needed programs/tools
672	check_perl_module("Pod::Usage", 0);
673	check_program("make", 0);
674	check_program("gcc", 0);
675	check_python_module("sphinx_rtd_theme", 1) if (!$virtualenv);
676	check_program("dot", 1);
677	check_program("convert", 1);
678
679	# Extra PDF files - should use 2 for is_optional
680	check_program("xelatex", 2) if ($pdf);
681	check_program("rsvg-convert", 2) if ($pdf);
682	check_program("latexmk", 2) if ($pdf);
683
684	check_distros();
685
686	if ($need_symlink) {
687		printf "\tsudo ln -sf %s /usr/bin/sphinx-build\n\n",
688		       which("sphinx-build-3");
689	}
690	if ($need_sphinx || $rec_sphinx_upgrade) {
691		my $min_activate = "$ENV{'PWD'}/${virtenv_prefix}${min_version}/bin/activate";
692		my @activates = glob "$ENV{'PWD'}/${virtenv_prefix}*/bin/activate";
693
694		@activates = sort {$b cmp $a} @activates;
695
696		if ($need_sphinx && scalar @activates > 0 && $activates[0] ge $min_activate) {
697			printf "\nNeed to activate a compatible Sphinx version on virtualenv with:\n";
698			printf "\t. $activates[0]\n";
699			deactivate_help();
700			exit (1);
701		} else {
702			my $rec_activate = "$virtenv_dir/bin/activate";
703			my $virtualenv = findprog("virtualenv-3");
704			my $rec_python3 = "";
705			$virtualenv = findprog("virtualenv-3.5") if (!$virtualenv);
706			$virtualenv = findprog("virtualenv") if (!$virtualenv);
707			$virtualenv = "virtualenv" if (!$virtualenv);
708
709			my $rel = "";
710			if (index($system_release, "Ubuntu") != -1) {
711				$rel = $1 if ($system_release =~ /Ubuntu\s+(\d+)[.]/);
712				if ($rel && $rel >= 16) {
713					$rec_python3 = " -p python3";
714				}
715			}
716			if (index($system_release, "Debian") != -1) {
717				$rel = $1 if ($system_release =~ /Debian\s+(\d+)/);
718				if ($rel && $rel >= 7) {
719					$rec_python3 = " -p python3";
720				}
721			}
722
723			printf "\t$virtualenv$rec_python3 $virtenv_dir\n";
724			printf "\t. $rec_activate\n";
725			printf "\tpip install -r $requirement_file\n";
726			deactivate_help();
727
728			$need++ if (!$rec_sphinx_upgrade);
729		}
730	}
731	printf "\n";
732
733	print "All optional dependencies are met.\n" if (!$optional);
734
735	if ($need == 1) {
736		die "Can't build as $need mandatory dependency is missing";
737	} elsif ($need) {
738		die "Can't build as $need mandatory dependencies are missing";
739	}
740
741	print "Needed package dependencies are met.\n";
742}
743
744#
745# Main
746#
747
748while (@ARGV) {
749	my $arg = shift(@ARGV);
750
751	if ($arg eq "--no-virtualenv") {
752		$virtualenv = 0;
753	} elsif ($arg eq "--no-pdf"){
754		$pdf = 0;
755	} elsif ($arg eq "--version-check"){
756		$version_check = 1;
757	} else {
758		print "Usage:\n\t$0 <--no-virtualenv> <--no-pdf> <--version-check>\n\n";
759		print "Where:\n";
760		print "\t--no-virtualenv\t- Recommend installing Sphinx instead of using a virtualenv\n";
761		print "\t--version-check\t- if version is compatible, don't check for missing dependencies\n";
762		print "\t--no-pdf\t- don't check for dependencies required to build PDF docs\n\n";
763		exit -1;
764	}
765}
766
767#
768# Determine the system type. There's no standard unique way that would
769# work with all distros with a minimal package install. So, several
770# methods are used here.
771#
772# By default, it will use lsb_release function. If not available, it will
773# fail back to reading the known different places where the distro name
774# is stored
775#
776
777$system_release = qx(lsb_release -d) if which("lsb_release");
778$system_release =~ s/Description:\s*// if ($system_release);
779$system_release = catcheck("/etc/system-release") if !$system_release;
780$system_release = catcheck("/etc/redhat-release") if !$system_release;
781$system_release = catcheck("/etc/lsb-release") if !$system_release;
782$system_release = catcheck("/etc/gentoo-release") if !$system_release;
783$system_release = catcheck("/etc/issue") if !$system_release;
784$system_release =~ s/\s+$//;
785
786check_needs;
787