X-Git-Url: https://git.donarmstrong.com/?a=blobdiff_plain;f=Debian%2FDebhelper%2FDh_Lib.pm;h=badbe87ede4361d8a69b0ed4196a07a4b91a3209;hb=4f8a46b36e961d1a64d466a63f3a7ef6c90bafe2;hp=82877340729920eec93ac569f7cd22ca59b47753;hpb=dffd90e48bd1c4bb45cf42b6394478a7d2590b5a;p=debhelper.git

diff --git a/Debian/Debhelper/Dh_Lib.pm b/Debian/Debhelper/Dh_Lib.pm
index 8287734..badbe87 100644
--- a/Debian/Debhelper/Dh_Lib.pm
+++ b/Debian/Debhelper/Dh_Lib.pm
@@ -2,7 +2,7 @@
 #
 # Library functions for debhelper programs, perl version.
 #
-# Joey Hess, GPL copyright 1997, 1998.
+# Joey Hess, GPL copyright 1997-2000.
 
 package Debian::Debhelper::Dh_Lib;
 use strict;
@@ -11,15 +11,20 @@ use Exporter;
 use vars qw(@ISA @EXPORT %dh);
 @ISA=qw(Exporter);
 @EXPORT=qw(&init &doit &complex_doit &verbose_print &error &warning &tmpdir
-	    &pkgfile &pkgext &isnative &autoscript &filearray &GetPackages
-	    &xargs
-	    %dh);
+	    &pkgfile &pkgext &pkgfilename &isnative &autoscript &filearray
+	    &filedoublearray &getpackages &basename &dirname &xargs %dh
+	    &compat &addsubstvar &delsubstvar &excludefile &package_arch
+	    &is_udeb &udeb_filename &debhelper_script_subst &escape_shell
+	    &inhibit_log);
 
-my $max_compat=3;
+my $max_compat=7;
 
 sub init {
 	# If DH_OPTIONS is set, prepend it @ARGV.
 	if (defined($ENV{DH_OPTIONS})) {
+		# Ignore leading/trailing whitespace.
+		$ENV{DH_OPTIONS}=~s/^\s+//;
+		$ENV{DH_OPTIONS}=~s/\s+$//;
 		unshift @ARGV,split(/\s+/,$ENV{DH_OPTIONS});
 	}
 
@@ -40,6 +45,23 @@ sub init {
 		%dh=Debian::Debhelper::Dh_Getopt::parseopts();
 	}
 
+	# Another way to set excludes.
+	if (exists $ENV{DH_ALWAYS_EXCLUDE} && length $ENV{DH_ALWAYS_EXCLUDE}) {
+		push @{$dh{EXCLUDE}}, split(":", $ENV{DH_ALWAYS_EXCLUDE});
+	}
+	
+	# Generate EXCLUDE_FIND.
+	if ($dh{EXCLUDE}) {
+		$dh{EXCLUDE_FIND}='';
+		foreach (@{$dh{EXCLUDE}}) {
+			my $x=$_;
+			$x=escape_shell($x);
+			$x=~s/\./\\\\./g;
+			$dh{EXCLUDE_FIND}.="-regex .\\*$x.\\* -or ";
+		}
+		$dh{EXCLUDE_FIND}=~s/ -or $//;
+	}
+	
 	# Check to see if DH_VERBOSE environment variable was set, if so,
 	# make sure verbose is on.
 	if (defined $ENV{DH_VERBOSE} && $ENV{DH_VERBOSE} ne "") {
@@ -52,18 +74,19 @@ sub init {
 		$dh{NO_ACT}=1;
 	}
 
+	my @allpackages=getpackages();
 	# Get the name of the main binary package (first one listed in
-	# debian/control).
-	my @allpackages=GetPackages();
-	$dh{MAINPACKAGE}=$allpackages[0];
+	# debian/control). Only if the main package was not set on the
+	# command line.
+	if (! exists $dh{MAINPACKAGE} || ! defined $dh{MAINPACKAGE}) {
+		$dh{MAINPACKAGE}=$allpackages[0];
+	}
 
 	# Check if packages to build have been specified, if not, fall back to
 	# the default, doing them all.
 	if (! defined $dh{DOPACKAGES} || ! @{$dh{DOPACKAGES}}) {
 		if ($dh{DOINDEP} || $dh{DOARCH} || $dh{DOSAME}) {
-			# User specified that all arch (in)dep package be 
-			# built, and there are none of that type.
-			error("I have no package to act on");
+			error("You asked that all arch in(dep) packages be built, but there are none of that type.");
 		}
 		push @{$dh{DOPACKAGES}},@allpackages;
 	}
@@ -79,19 +102,58 @@ sub init {
 	# the command line may affect it.
 	$dh{FIRSTPACKAGE}=${$dh{DOPACKAGES}}[0];
 
-	# Split the U_PARAMS up into an array.
-	my $u=$dh{U_PARAMS};
-	undef $dh{U_PARAMS};
-	if (defined $u) {
-		push @{$dh{U_PARAMS}}, split(/\s+/,$u);
+	# If no error handling function was specified, just propigate
+	# errors out.
+	if (! exists $dh{ERROR_HANDLER} || ! defined $dh{ERROR_HANDLER}) {
+		$dh{ERROR_HANDLER}='exit \$?';
+	}
+}
+
+# Run at exit. Add the command to the log files for the packages it acted
+# on, if it's exiting successfully.
+my $write_log=1;
+sub END {
+	if ($? == 0 && $write_log) {
+		my $cmd=basename($0);
+		foreach my $package (@{$dh{DOPACKAGES}}) {
+			my $ext=pkgext($package);
+			open(LOG, ">>", "debian/${ext}debhelper.log") || error("failed to write to log");
+			print LOG $cmd."\n";
+			close LOG;
+		}
 	}
 }
 
-# Escapes out shell metacharacters in a word of shell script.
-sub escape_shell { my $word=shift;
-	# This list is from _Unix in a Nutshell_. (except '#')
-	$word=~s/([\s!"\$()*+#;<>?@\[\]\\`|~])/\\$1/g;
-	return $word;
+sub inhibit_log {
+	$write_log=0;
+}
+
+# Pass it an array containing the arguments of a shell command like would
+# be run by exec(). It turns that into a line like you might enter at the
+# shell, escaping metacharacters and quoting arguments that contain spaces.
+sub escape_shell {
+	my @args=@_;
+	my $line="";
+	my @ret;
+	foreach my $word (@args) {
+		if ($word=~/\s/) {
+			# Escape only a few things since it will be quoted.
+			# Note we use double quotes because you cannot
+			# escape ' in single quotes, while " can be escaped
+			# in double.
+			# This does make -V"foo bar" turn into "-Vfoo bar",
+			# but that will be parsed identically by the shell
+			# anyway..
+			$word=~s/([\n`\$"\\])/\\$1/g;
+			push @ret, "\"$word\"";
+		}
+		else {
+			# This list is from _Unix in a Nutshell_. (except '#')
+			$word=~s/([\s!"\$()*+#;<>?@\[\]\\`|~])/\\$1/g;
+			push @ret,$word;
+		}
+	}
+	return join(' ', @ret);
 }
 
 # Run a command, and display the command to stdout if verbose mode is on.
@@ -101,12 +163,11 @@ sub escape_shell { my $word=shift;
 # Note that this cannot handle complex commands, especially anything
 # involving redirection. Use complex_doit instead.
 sub doit {
-	verbose_print(join(" ",map { escape_shell($_) } @_));
-	
+	verbose_print(escape_shell(@_));
+
 	if (! $dh{NO_ACT}) {
-		system(@_) == 0
-			|| error("command returned error code");
-		
+		my $ret=system(@_);
+		$ret == 0 || error("command returned error code $ret");
 	}
 }
 
@@ -132,7 +193,8 @@ sub xargs {
 	my $args=shift;
 
         # The kernel can accept command lines up to 20k worth of characters.
-	my $command_max=20000;
+	my $command_max=20000; # LINUX SPECIFIC!!
+			# I could use POSIX::ARG_MAX, but that would be slow.
 
 	# Figure out length of static portion of command.
 	my $static_length=0;
@@ -160,60 +222,98 @@ sub xargs {
 }
 
 # Print something if the verbose flag is on.
-sub verbose_print { my $message=shift;
+sub verbose_print {
+	my $message=shift;
+	
 	if ($dh{VERBOSE}) {
 		print "\t$message\n";
 	}
 }
 
 # Output an error message and exit.
-sub error { my $message=shift;
+sub error {
+	my $message=shift;
+
 	warning($message);
 	exit 1;
 }
 
 # Output a warning.
-sub warning { my $message=shift;
+sub warning {
+	my $message=shift;
+	
 	print STDERR basename($0).": $message\n";
 }
 
 # Returns the basename of the argument passed to it.
-sub basename { my $fn=shift;
+sub basename {
+	my $fn=shift;
+
+	$fn=~s/\/$//g; # ignore trailing slashes
 	$fn=~s:^.*/(.*?)$:$1:;
 	return $fn;
 }
 
 # Returns the directory name of the argument passed to it.
-sub dirname { my $fn=shift;
+sub dirname {
+	my $fn=shift;
+	
+	$fn=~s/\/$//g; # ignore trailing slashes
 	$fn=~s:^(.*)/.*?$:$1:;
 	return $fn;
 }
 
-# Pass in a number, will return true iff the current compatability level
+# Pass in a number, will return true iff the current compatibility level
 # is less than or equal to that number.
-sub compat {
-	my $num=shift;
+{
+	my $warned_compat=0;
+	my $c;
+
+	sub compat {
+		my $num=shift;
 	
-	my $c=1;
-	if (defined $ENV{DH_COMPAT}) {
-		$c=$ENV{DH_COMPAT};
-	}
+		if (! defined $c) {
+			$c=1;
+			if (defined $ENV{DH_COMPAT}) {
+				$c=$ENV{DH_COMPAT};
+			}
+			elsif (-e 'debian/compat') {
+				# Try the file..
+				open (COMPAT_IN, "debian/compat") || error "debian/compat: $!";
+				my $l=<COMPAT_IN>;
+				if (! defined $l || ! length $l) {
+					warning("debian/compat is empty, assuming level $c");
+				}
+				else {
+					chomp $l;
+					$c=$l;
+				}
+			}
+		}
 
-	if ($c > $max_compat) {
-		error("Sorry, but $max_compat is the highest compatability level of debhelper currently supported.");
-	}
+		if ($c < 4 && ! $warned_compat) {
+			warning("Compatibility levels before 4 are deprecated.");
+			$warned_compat=1;
+		}
+	
+		if ($c > $max_compat) {
+			error("Sorry, but $max_compat is the highest compatibility level supported by this debhelper.");
+		}
 
-	return ($c <= $num);
+		return ($c <= $num);
+	}
 }
 
 # Pass it a name of a binary package, it returns the name of the tmp dir to
 # use, for that package.
-sub tmpdir { my $package=shift;
+sub tmpdir {
+	my $package=shift;
+
 	if ($dh{TMPDIR}) {
 		return $dh{TMPDIR};
 	}
 	elsif (compat(1) && $package eq $dh{MAINPACKAGE}) {
-		# This is for back-compatability with the debian/tmp tradition.
+		# This is for back-compatibility with the debian/tmp tradition.
 		return "debian/tmp";
 	}
 	else {
@@ -228,31 +328,57 @@ sub tmpdir { my $package=shift;
 #   * debian/package.filename.buildarch
 #   * debian/package.filename
 #   * debian/file (if the package is the main package)
+# If --name was specified then tonly the first two are tried, and they must
+# have the name after the pacage name:
+#   * debian/package.name.filename.buildarch
+#   * debian/package.name.filename
 sub pkgfile {
 	my $package=shift;
 	my $filename=shift;
 
-	if (-f "debian/$package.$filename.".buildarch()) {
-		return "debian/$package.$filename.".buildarch();
+	if (defined $dh{NAME}) {
+		$filename="$dh{NAME}.$filename";
 	}
-	elsif (-f "debian/$package.$filename") {
-		return "debian/$package.$filename";
+	
+	my @try=("debian/$package.$filename.".buildarch(),
+		 "debian/$package.$filename");
+	if ($package eq $dh{MAINPACKAGE}) {
+		push @try, "debian/$filename";
 	}
-	elsif ($package eq $dh{MAINPACKAGE} && -f "debian/$filename") {
-		return "debian/$filename";
+	
+	foreach my $file (@try) {
+		if (-f $file &&
+		    (! $dh{IGNORE} || ! exists $dh{IGNORE}->{$file})) {
+			return $file;
+		}
+
 	}
-	else {
+
+	return "";
+
+}
+
+# Pass it a name of a binary package, it returns the name to prefix to files
+# in debian/ for this package.
+sub pkgext {
+	my $package=shift;
+
+	if (compat(1) and $package eq $dh{MAINPACKAGE}) {
 		return "";
 	}
+	return "$package.";
 }
 
-# Pass it a name of a binary package, it returns the name to prefix to files
-# in debian for this package.
-sub pkgext { my $package=shift;
-	if ($package ne $dh{MAINPACKAGE}) {
-		return "$package.";
+# Pass it the name of a binary package, it returns the name to install
+# files by in eg, etc. Normally this is the same, but --name can override
+# it.
+sub pkgfilename {
+	my $package=shift;
+
+	if (defined $dh{NAME}) {
+		return $dh{NAME};
 	}
-	return "";
+	return $package;
 }
 
 # Returns 1 if the package is a native debian package, null otherwise.
@@ -261,33 +387,31 @@ sub pkgext { my $package=shift;
 	# Caches return code so it only needs to run dpkg-parsechangelog once.
 	my %isnative_cache;
 	
-	sub isnative { my $package=shift;
-		if (! defined $isnative_cache{$package}) {
-			# Make sure we look at the correct changelog.
-			my $isnative_changelog=pkgfile($package,"changelog");
-			if (! $isnative_changelog) {
-				$isnative_changelog="debian/changelog";
-			}
+	sub isnative {
+		my $package=shift;
 
-			# Get the package version.
-			my $version=`dpkg-parsechangelog -l$isnative_changelog`;
-			($dh{VERSION})=$version=~m/Version:\s*(.*)/m;
-
-			# Did the changelog parse fail?
-			if (! defined $dh{VERSION}) {
-				error("changelog parse failure");
-			}
+		return $isnative_cache{$package} if defined $isnative_cache{$package};
+		
+		# Make sure we look at the correct changelog.
+		my $isnative_changelog=pkgfile($package,"changelog");
+		if (! $isnative_changelog) {
+			$isnative_changelog="debian/changelog";
+		}
+		# Get the package version.
+		my $version=`dpkg-parsechangelog -l$isnative_changelog`;
+		($dh{VERSION})=$version=~m/Version:\s*(.*)/m;
+		# Did the changelog parse fail?
+		if (! defined $dh{VERSION}) {
+			error("changelog parse failure");
+		}
 
-			# Is this a native Debian package?
-			if ($dh{VERSION}=~m/.*-/) {
-				$isnative_cache{$package}=0;
-			}
-			else {
-				$isnative_cache{$package}=1;
-			}
+		# Is this a native Debian package?
+		if ($dh{VERSION}=~m/.*-/) {
+			return $isnative_cache{$package}=0;
+		}
+		else {
+			return $isnative_cache{$package}=1;
 		}
-	
-		return $isnative_cache{$package};
 	}
 }
 
@@ -299,8 +423,13 @@ sub pkgext { my $package=shift;
 # 2: script to add to
 # 3: filename of snippet
 # 4: sed to run on the snippet. Ie, s/#PACKAGE#/$PACKAGE/
-sub autoscript { my $package=shift; my $script=shift; my $filename=shift; my $sed=shift || "";
-	# This is the file we will append to.
+sub autoscript {
+	my $package=shift;
+	my $script=shift;
+	my $filename=shift;
+	my $sed=shift || "";
+
+	# This is the file we will modify.
 	my $outfile="debian/".pkgext($package)."$script.debhelper";
 
 	# Figure out what shell script snippet to use.
@@ -318,25 +447,140 @@ sub autoscript { my $package=shift; my $script=shift; my $filename=shift; my $se
 		}
 	}
 
-	# TODO: do this in perl, perhaps?
-	complex_doit("echo \"# Automatically added by ".basename($0)."\">> $outfile");
-	complex_doit("sed \"$sed\" $infile >> $outfile");
-	complex_doit("echo '# End automatically added section' >> $outfile");
+	if (-e $outfile && ($script eq 'postrm' || $script eq 'prerm')
+	   && !compat(5)) {
+		# Add fragments to top so they run in reverse order when removing.
+		complex_doit("echo \"# Automatically added by ".basename($0)."\"> $outfile.new");
+		complex_doit("sed \"$sed\" $infile >> $outfile.new");
+		complex_doit("echo '# End automatically added section' >> $outfile.new");
+		complex_doit("cat $outfile >> $outfile.new");
+		complex_doit("mv $outfile.new $outfile");
+	}
+	else {
+		complex_doit("echo \"# Automatically added by ".basename($0)."\">> $outfile");
+		complex_doit("sed \"$sed\" $infile >> $outfile");
+		complex_doit("echo '# End automatically added section' >> $outfile");
+	}
 }
 
-# Reads in the specified file, one word at a time, and returns an array of
-# the result.
-sub filearray { my $file=shift;
+# Removes a whole substvar line.
+sub delsubstvar {
+	my $package=shift;
+	my $substvar=shift;
+
+	my $ext=pkgext($package);
+	my $substvarfile="debian/${ext}substvars";
+
+	if (-e $substvarfile) {
+		complex_doit("grep -s -v '^${substvar}=' $substvarfile > $substvarfile.new || true");
+		doit("mv", "$substvarfile.new","$substvarfile");
+	}
+}
+				
+# Adds a dependency on some package to the specified
+# substvar in a package's substvar's file.
+sub addsubstvar {
+	my $package=shift;
+	my $substvar=shift;
+	my $deppackage=shift;
+	my $verinfo=shift;
+	my $remove=shift;
+
+	my $ext=pkgext($package);
+	my $substvarfile="debian/${ext}substvars";
+	my $str=$deppackage;
+	$str.=" ($verinfo)" if defined $verinfo && length $verinfo;
+
+	# Figure out what the line will look like, based on what's there
+	# now, and what we're to add or remove.
+	my $line="";
+	if (-e $substvarfile) {
+		my %items;
+		open(SUBSTVARS_IN, "$substvarfile") || error "read $substvarfile: $!";
+		while (<SUBSTVARS_IN>) {
+			chomp;
+			if (/^\Q$substvar\E=(.*)/) {
+				%items = map { $_ => 1} split(", ", $1);
+				
+				last;
+			}
+		}
+		close SUBSTVARS_IN;
+		if (! $remove) {
+			$items{$str}=1;
+		}
+		else {
+			delete $items{$str};
+		}
+		$line=join(", ", sort keys %items);
+	}
+	elsif (! $remove) {
+		$line=$str;
+	}
+
+	if (length $line) {
+		 complex_doit("(grep -s -v ${substvar} $substvarfile; echo ".escape_shell("${substvar}=$line").") > $substvarfile.new");
+		 doit("mv", "$substvarfile.new", $substvarfile);
+	}
+	else {
+		delsubstvar($package,$substvar);
+	}
+}
+
+# Reads in the specified file, one line at a time. splits on words, 
+# and returns an array of arrays of the contents.
+# If a value is passed in as the second parameter, then glob
+# expansion is done in the directory specified by the parameter ("." is
+# frequently a good choice).
+sub filedoublearray {
+	my $file=shift;
+	my $globdir=shift;
+
 	my @ret;
-	open (DH_FARRAY_IN,"<$file") || error("cannot read $file: $1");
+	open (DH_FARRAY_IN, $file) || error("cannot read $file: $1");
 	while (<DH_FARRAY_IN>) {
-		push @ret,split(' ',$_);
+		chomp;
+		# Only ignore comments and empty lines in v5 mode.
+		if (! compat(4)) {
+			next if /^#/ || /^$/;
+		}
+		my @line;
+		# Only do glob expansion in v3 mode.
+		#
+		# The tricky bit is that the glob expansion is done
+		# as if we were in the specified directory, so the
+		# filenames that come out are relative to it.
+		if (defined $globdir && ! compat(2)) {
+			for (map { glob "$globdir/$_" } split) {
+				s#^$globdir/##;
+				push @line, $_;
+			}
+		}
+		else {
+			@line = split;
+		}
+		push @ret, [@line];
 	}
 	close DH_FARRAY_IN;
 	
 	return @ret;
 }
 
+# Reads in the specified file, one word at a time, and returns an array of
+# the result. Can do globbing as does filedoublearray.
+sub filearray {
+	return map { @$_ } filedoublearray(@_);
+}
+
+# Passed a filename, returns true if -X says that file should be excluded.
+sub excludefile {
+        my $filename = shift;
+        foreach my $f (@{$dh{EXCLUDE}}) {
+                return 1 if $filename =~ /\Q$f\E/;
+        }
+        return 0;
+}
+
 # Returns the build architecture. (Memoized)
 {
 	my $arch;
@@ -344,17 +588,37 @@ sub filearray { my $file=shift;
 	sub buildarch {
   		return $arch if defined $arch;
 
-		$arch=`dpkg --print-architecture` || error($!);
+		$arch=`dpkg-architecture -qDEB_HOST_ARCH 2>/dev/null` || error("dpkg-architecture failed");
 		chomp $arch;
 		return $arch;
 	}
 }
 
+# Passed an arch and a list of arches to match against, returns true if matched
+sub samearch {
+	my $arch=shift;
+	my @archlist=split(/\s+/,shift);
+
+	foreach my $a (@archlist) {
+		system("dpkg-architecture", "-a$arch", "-i$a") == 0 && return 1;
+	}
+
+	return 0;
+}
+
 # Returns a list of packages in the control file.
 # Must pass "arch" or "indep" or "same" to specify arch-dependant or
 # -independant or same arch packages. If nothing is specified, returns all
 # packages.
-sub GetPackages { my $type=shift;
+# As a side effect, populates %package_arches and %package_types with the
+# types of all packages (not only those returned).
+my (%package_types, %package_arches);
+sub getpackages {
+	my $type=shift;
+
+	%package_types=();
+	%package_arches=();
+	
 	$type="" if ! defined $type;
 	
 	# Look up the build arch if we need to.
@@ -365,23 +629,41 @@ sub GetPackages { my $type=shift;
 
 	my $package="";
 	my $arch="";
+	my $package_type;
 	my @list=();
-	open (CONTROL,"<debian/control") ||
+	my %seen;
+	open (CONTROL, 'debian/control') ||
 		error("cannot read debian/control: $!\n");
 	while (<CONTROL>) {
 		chomp;
 		s/\s+$//;
 		if (/^Package:\s*(.*)/) {
 			$package=$1;
+			# Detect duplicate package names in the same control file.
+			if (! $seen{$package}) {
+				$seen{$package}=1;
+			}
+			else {
+				error("debian/control has a duplicate entry for $package");
+			}
+			$package_type="deb";
 		}
 		if (/^Architecture:\s*(.*)/) {
 			$arch=$1;
 		}
+		if (/^(?:X[BC]*-)?Package-Type:\s*(.*)/) {
+			$package_type=$1;
+		}
+		
 		if (!$_ or eof) { # end of stanza.
+			if ($package) {
+				$package_types{$package}=$package_type;
+				$package_arches{$package}=$arch;
+			}
 			if ($package &&
 			    (($type eq 'indep' && $arch eq 'all') ||
 			     ($type eq 'arch' && $arch ne 'all') ||
-			     ($type eq 'same' && ($arch eq 'any' || $arch =~ /\b$buildarch\b/)) ||
+			     ($type eq 'same' && ($arch eq 'any' || samearch($buildarch, $arch))) ||
 			     ! $type)) {
 				push @list, $package;
 				$package="";
@@ -394,4 +676,67 @@ sub GetPackages { my $type=shift;
 	return @list;
 }
 
+# Returns the arch a package will build for.
+sub package_arch {
+	my $package=shift;
+	
+	if (! exists $package_arches{$package}) {
+		warning "package $package is not in control info";
+		return buildarch();
+	}
+	return $package_arches{$package} eq 'all' ? "all" : buildarch();
+}
+
+# Return true if a given package is really a udeb.
+sub is_udeb {
+	my $package=shift;
+	
+	if (! exists $package_types{$package}) {
+		warning "package $package is not in control info";
+		return 0;
+	}
+	return $package_types{$package} eq 'udeb';
+}
+
+# Generates the filename that is used for a udeb package.
+sub udeb_filename {
+	my $package=shift;
+	
+	my $filearch=package_arch($package);
+	isnative($package); # side effect
+	my $version=$dh{VERSION};
+	$version=~s/^[0-9]+://; # strip any epoch
+	return "${package}_${version}_$filearch.udeb";
+}
+
+# Handles #DEBHELPER# substitution in a script; also can generate a new
+# script from scratch if none exists but there is a .debhelper file for it.
+sub debhelper_script_subst {
+	my $package=shift;
+	my $script=shift;
+	
+	my $tmp=tmpdir($package);
+	my $ext=pkgext($package);
+	my $file=pkgfile($package,$script);
+
+	if ($file ne '') {
+		if (-f "debian/$ext$script.debhelper") {
+			# Add this into the script, where it has #DEBHELPER#
+			complex_doit("perl -pe 's~#DEBHELPER#~qx{cat debian/$ext$script.debhelper}~eg' < $file > $tmp/DEBIAN/$script");
+		}
+		else {
+			# Just get rid of any #DEBHELPER# in the script.
+			complex_doit("sed s/#DEBHELPER#// < $file > $tmp/DEBIAN/$script");
+		}
+		doit("chown","0:0","$tmp/DEBIAN/$script");
+		doit("chmod",755,"$tmp/DEBIAN/$script");
+	}
+	elsif ( -f "debian/$ext$script.debhelper" ) {
+		complex_doit("printf '#!/bin/sh\nset -e\n' > $tmp/DEBIAN/$script");
+		complex_doit("cat debian/$ext$script.debhelper >> $tmp/DEBIAN/$script");
+		doit("chown","0:0","$tmp/DEBIAN/$script");
+		doit("chmod",755,"$tmp/DEBIAN/$script");
+	}
+}
+
 1