dpkg/scripts/dpkg-source.pl

#!/usr/bin/perl

$dpkglibdir= ".";
$version= '1.3.0'; # This line modified by Makefile

$sourcestyle= 'X';

use POSIX;
use POSIX qw(:errno_h :signal_h);

push(@INC,$dpkglibdir);
require 'controllib.pl';

sub usageversion {
    print STDERR
"Debian GNU/Linux dpkg-source $version.  Copyright (C) 1996
Ian Jackson.  This is free software; see the GNU General Public Licence
version 2 or later for copying conditions.  There is NO warranty.

Usage:  dpkg-source -x <filename>.dsc
        dpkg-source -b <directory> [<orig-directory>|<orig-targz>|\'\']
Build options:   -c<controlfile>     get control info from this file
                 -l<changelogfile>   get per-version info from this file
                 -F<changelogformat> force change log format
                 -V<name>=<value>    set a substitution variable
                 -T<varlistfile>     read variables here, not debian/substvars
                 -D<field>=<value>   override or add a .dsc field and value
                 -U<field>           remove a field
                 -sa                 auto select orig source (-sA is default)
                 -sk                 use packed orig source (unpack & keep)
                 -sp                 use packed orig source (unpack & remove)
                 -su                 use unpacked orig source (pack & keep)
                 -sr                 use unpacked orig source (pack & remove)
                 -ss                 trust packed & unpacked orig src are same
                 -sn                 there is no diff, do main tarfile only
                 -sA,-sK,-sP,-sU,-sR like -sa,-sp,-sk,-su,-sr but may overwrite
Extract options: -sp (default)       leave orig source packed in current dir
                 -sn                 do not copy original source to current dir
                 -su                 unpack original source tree too
General options: -h                  print this message
";
}

$i=100;grep($fieldimps{$_}=$i--,
          qw(Source Version Binary Maintainer Architecture Standards-Version));

while (@ARGV && $ARGV[0] =~ m/^-/) {
    $_=shift(@ARGV);
    if (m/^-b$/) {
        &setopmode('build');
    } elsif (m/^-x$/) {
        &setopmode('extract');
    } elsif (m/^-s([akpursnAKPUR])$/) {
        $sourcestyle= $1;
    } elsif (m/^-c/) {
        $controlfile= $';
    } elsif (m/^-l/) {
        $changelogfile= $';
    } elsif (m/^-F([0-9a-z]+)$/) {
        $changelogformat=$1;
    } elsif (m/^-D([^\=:]+)[=:]/) {
        $override{$1}= $';
    } elsif (m/^-U([^\=:]+)$/) {
        $remove{$1}= 1;
    } elsif (m/^-V(\w[-:0-9A-Za-z]*)[=:]/) {
        $substvar{$1}= $';
    } elsif (m/^-T/) {
        $varlistfile= $';
    } elsif (m/^-h$/) {
        &usageversion; exit(0);
    } elsif (m/^--$/) {
        last;
    } else {
        &usageerr("unknown option $_");
    }
}

defined($opmode) || &usageerr("need -x or -b");

if ($opmode eq 'build') {

    $sourcestyle =~ y/X/A/;
    $sourcestyle =~ m/[akpursnAKPUR]/ ||
        &usageerr("source handling style -s$sourcestyle not allowed with -b");

    @ARGV || &usageerr("-b needs a directory");
    @ARGV<=2 || &usageerr("-b takes at most a directory and an orig source argument");
    $dir= shift(@ARGV);
    $dir= "./$dir" unless $dir =~ m:^/:; $dir =~ s,/*$,,;
    stat($dir) || &error("cannot stat directory $dir: $!");
    -d $dir || &error("directory argument $dir is not a directory");

    $changelogfile= "$dir/debian/changelog" unless defined($changelogfile);
    $controlfile= "$dir/debian/control" unless defined($controlfile);
    
    &parsechangelog;
    &parsecontrolfile;

    $archspecific=0;
    for $_ (keys %fi) {
        $v= $fi{$_};
        if (s/^C //) {
#print STDERR "G key >$_< value >$v<\n";
            if (m/^Source$/) { &setsourcepackage; }
            elsif (m/^Standards-Version$|^Maintainer$/) { $f{$_}= $v; }
            elsif (s/^X[BC]*S[BC]*-//i) { $f{$_}= $v; }
            elsif (m/^(Section|Priority|Files)$/ || m/^X[BC]+-/i) { }
            else { &unknown('general section of control info file'); }
        } elsif (s/^C(\d+) //) {
#print STDERR "P key >$_< value >$v<\n";
            $i=$1; $p=$fi{"C$i Package"};
            push(@binarypackages,$p) unless $packageadded{$p}++;
            if (m/^Architecture$/) {
#print STDERR "$p >$v< >".join(' ',@sourcearch)."<\n";
                if ($v eq 'any') {
                    @sourcearch= ('any');
                } elsif ($v eq 'all') {
                    if (!@sourcearch || $sourcearch[0] eq 'all') {
                        @sourcearch= ('all');
                    } else {
                        @sourcearch= ('any');
                    }
                } else {
                    if (grep($sourcearch[0] eq $_, 'any','all')) {
                        @sourcearch= ('any');
                    } else {
                        for $a (split(/\s+/,$v)) {
                            &error("architecture $a only allowed on its own".
                                   " (list for package $p is \`$a')")
                                   if grep($a eq $_, 'any','all');
                            push(@sourcearch,$a) unless $archadded{$a}++;
                        }
                    }
                }
                $f{'Architecture'}= join(' ',@sourcearch);
            } elsif (s/^X[BC]*S[BC]*-//i) {
                $f{$_}= $v;
            } elsif (m/^(Package|Essential|Pre-Depends|Depends|Provides)$/ ||
                     m/^(Recommends|Suggests|Optional|Conflicts|Replaces)$/ ||
                     m/^(Description|Section|Priority)$/ ||
                     m/^X[CS]+-/i) {
            } else {
                &unknown("package's section of control info file");
            }
        } elsif (s/^L //) {
#print STDERR "L key >$_< value >$v<\n";
            if (m/^Source$/) {
                &setsourcepackage;
            } elsif (m/^Version$/) {
                $f{$_}= $v;
            } elsif (s/^X[BS]*C[BS]*-//i) {
                $f{$_}= $v;
            } elsif (m/^(Maintainer|Changes|Urgency|Distribution|Date)$/ ||
                     m/^X[BS]+-/i) {
            } else {
                &unknown("parsed version of changelog");
            }
        } else {
            &internerr("value from nowhere, with key >$_< and value >$v<");
        }
    }

    $f{'Binary'}= join(', ',@binarypackages);
    for $f (keys %override) { $f{&capit($f)}= $override{$f}; }

    for $f (qw(Version)) {
        defined($f{$f}) || &error("missing information for critical output field $f");
    }
    for $f (qw(Maintainer Architecture Standards-Version)) {
        defined($f{$f}) || &warn("missing information for output field $f");
    }
    defined($sourcepackage) || &error("unable to determine source package name !");
    $f{'Source'}= $sourcepackage;
    for $f (keys %remove) { delete $f{&capit($f)}; }

    $version= $f{'Version'};
    $version =~ s/^\d+://; $upstreamversion= $version; $upstreamversion =~ s/-[^-]*$//;
    $basenamerev= $sourcepackage.'_'.$version;
    $basename= $sourcepackage.'_'.$upstreamversion;
    $basedirname= $basename;
#print STDERR ">$basedirname<\n";
    $basedirname =~ s/_/-/;
#print STDERR ">$basedirname<\n";

    $origdir= "$dir.orig";
    $origtargz= "$basename.orig.tar.gz";
    if (@ARGV) {
        $origarg= shift(@ARGV);
        if (length($origarg)) {
            stat($origarg) || &error("cannot stat orig argument $origarg: $!");
            if (-d _) {
                $origdir= $origarg;
                $origdir= "./$origdir" unless $origdir =~ m,^/,; $origdir =~ s,/*$,,;
                $sourcestyle =~ y/aA/rR/;
                $sourcestyle =~ m/[ursURS]/ ||
                    &error("orig argument is unpacked but source handling style".
                           " -s$sourcestyle calls for packed (.orig.tar.gz)");
            } elsif (-f _) {
                $origtargz= $origarg;
                $sourcestyle =~ y/aA/pP/;
                $sourcestyle =~ m/[kpsKPS]/ ||
                    &error("orig argument is packed but source handling style".
                           " -s$sourcestyle calls for unpacked (.orig/)");
            } else {
                &error("orig argument $origarg is not a plain file or directory");
            }
        } else {
            $sourcestyle =~ y/aA/nn/;
            $sourcestyle =~ m/n/ ||
                &error("orig argument is empty (means no orig, no diff)".
                       " but source handling style -s$sourcestyle wants something");
        }
    }

    if ($sourcestyle =~ m/[aA]/) {
        if (stat("$origtargz")) {
            -f _ || &error("packed orig \`$origtargz' exists but is not a plain file");
            $sourcestyle =~ y/aA/pP/;
        } elsif ($! != ENOENT) {
            &syserr("unable to stat putative packed orig \`$origtargz'");
        } elsif (stat("$origdir")) {
            -d _ || &error("unpacked orig \`$origdir' exists but is not a directory");
            $sourcestyle =~ y/aA/rR/;
        } elsif ($! != ENOENT) {
            &syserr("unable to stat putative unpacked orig \`$origdir'");
        } else {
            $sourcestyle =~ y/aA/nn/;
        }
    }
    $dirbase= $dir; $dirbase =~ s,/?$,,; $dirbase =~ s,[^/]+$,,; $dirname= $&;
    $dirname eq $basedirname || &warn("source directory \`$dir' is not <sourcepackage>".
                                      "-<upstreamversion> \`$basedirname'");
    
    if ($sourcestyle ne 'n') {
        $origdirbase= $origdir; $origdirbase =~ s,/?$,,;
        $origdirbase =~ s,[^/]+$,,; $origdirname= $&;

        $origdirname eq "$basedirname.orig" ||
            &warn(".orig directory name $origdirname is not <package>".
                  "-<upstreamversion> (wanted $basedirname.orig)");
        $tardirbase= $origdirbase; $tardirname= $origdirname;

        $tarname= $origtargz;
        $tarname eq "$basename.orig.tar.gz" ||
            &warn(".orig.tar.gz name $tarname is not <package>-<upstreamversion>".
                  ".orig.tar.gz (wanted $basename.orig.tar.gz)");
    } else {
        $tardirbase= $dirbase; $tardirname= $dirname;
        $tarname= "$basename.tar.gz";
    }

#print STDERR ">$dir|$origdir|$origtargz|$sourcestyle<\n";

    if ($sourcestyle =~ m/[nurUR]/) {

        if (stat($tarname)) {
            $sourcestyle =~ m/[nUR]/ ||
                &error("tarfile \`$tarname' already exists, not overwriting,".
                       " giving up; use -sU or -sR to override");
        } elsif ($! != ENOENT) {
            &syserr("unable to check for existence of \`$tarname'");
        }

#print STDERR ">$tarname|$tardirbase|$tardirname<\n";
    
        print("$progname: building $sourcepackage in $tarname\n")
            || &syserr("write building tar message");
        &forkgzipwrite("$tarname.new");
        defined($c2= fork) || &syserr("fork for tar");
        if (!$c2) {
            chdir($tardirbase) || &syserr("chdir to above (orig) source $tardirbase");
#system('pwd && ls');
            open(STDOUT,">&GZIP") || &syserr("reopen gzip for tar");
            # FIXME: put `--' argument back when tar is fixed
            exec('tar','-cO',$tardirname); &syserr("exec tar");
        }
        close(GZIP);
        &reapgzip;
        $c2 == waitpid($c2,0) || &syserr("wait for tar");
        $? && !(WIFSIGNALED($c2) && WTERMSIG($c2) == SIGPIPE) && subprocerr("tar");
        rename("$tarname.new",$tarname) ||
            &syserr("unable to rename \`$tarname.new' (newly created) to \`$tarname'");

    } else {
        
        print("$progname: building $sourcepackage using existing $tarname\n")
            || &syserr("write using existing tar message");
        
    }
    
    addfile("$tarname");

    if ($sourcestyle =~ m/[kpKP]/) {

        if (stat($origdir)) {
            $sourcestyle =~ m/[KP]/ ||
                &error("orig dir \`$origdir' already exists, not overwriting,".
                       " giving up; use -sA, -sK or -sP to override");
            erasedir($origdir);
        } elsif ($! != ENOENT) {
            &syserr("unable to check for existence of orig dir \`$origdir'");
        }

        $expectprefix= $origdir; $expectprefix =~ s,^\./,,;
        checktarsane($origtargz,$expectprefix);
        mkdir("$origtargz.tmp-nest",0755) ||
            &syserr("unable to create \`$origdirtargz.tmp-nest'");
        extracttar($origtargz,"$origtargz.tmp-nest");
        rename("$origtargz.tmp-nest/$expectprefix",$expectprefix) ||
            &syserr("unable to rename \`$origtargz.tmp-nest/$expectprefix' to ".
                    "\`$expectprefix'");
        rmdir("$origtargz.tmp-nest") ||
            &syserr("unable to remove \`$origdirtargz.tmp-nest'");

    }
        
    if ($sourcestyle =~ m/[kpursKPUR]/) {
        
        print("$progname: building $sourcepackage in $basenamerev.diff.gz\n")
            || &syserr("write building diff message");
        &forkgzipwrite("$basenamerev.diff.gz");

        defined($c2= open(FIND,"-|")) || &syserr("fork for find");
        if (!$c2) {
            chdir($dir) || &syserr("chdir to $dir for find");
            exec('find','.','-print0'); &syserr("exec find");
        }
        $/= "\0";

      file:
        while (defined($fn= <FIND>)) {
            $fn =~ s/\0$//; $fn =~ s,^\./,,;
            lstat("$dir/$fn") || &syserr("cannot stat file $dir/$fn");
            if (-l _) {
                $type{$fn}= 'symlink';
                &checktype('-l') || next;
                defined($n= readlink("$dir/$fn")) ||
                    &syserr("cannot read link $dir/$fn");
                defined($n2= readlink("$origdir/$fn")) ||
                    &syserr("cannot read orig link $origdir/$fn");
                $n eq $n2 || &unrepdiff2("symlink to $n2","symlink to $n");
            } elsif (-f _) {
                $type{$fn}= 'plain file';
                if (!lstat("$origdir/$fn")) {
                    $! == ENOENT || &syserr("cannot stat orig file $origdir/$fn");
                    $ofnread= '/dev/null';
                } elsif (-f _) {
                    $ofnread= "$origdir/$fn";
                } else {
                    &unrepdiff2("something else","plain file");
                    next;
                }
                defined($c3= open(DIFFGEN,"-|")) || &syserr("fork for diff");
                if (!$c3) {
                    exec('diff','-u',
                         '-L',"$basedirname.orig/$fn",
                         '-L',"$basedirname/$fn",
                         '--',"$ofnread","$dir/$fn"); &syserr("exec diff");
                }
                $difflinefound= 0;
                $/= "\n";
                while (<DIFFGEN>) {
                    if (m/^binary/i) {
                        close(DIFFGEN); $/= "\0";
                        &unrepdiff("binary file contents changed");
                        next file;
                    } elsif (m/^[-+\@ ]/) {
                        $difflinefound=1;
                    } else {
                        s/\n$//;
                        &internerr("unknown line from diff -u on $dir/$fn: \`$_'");
                    }
                    print(GZIP $_) || &syserr("failed to write to gzip");
                }
                close(DIFFGEN); $/= "\0";
                if (WIFEXITED($?) && (($es=WEXITSTATUS($?))==0 || $es==1)) {
                    if ($es==1 && !$difflinefound) {
                        &unrepdiff("diff gave 1 but no diff lines found");
                    }
                } else {
                    subprocerr("diff on $dir/$fn");
                }
            } elsif (-p _) {
                $type{$fn}= 'pipe';
                &checktype('-p');
            } elsif (-b _ || -c _ || -S _) {
                &unrepdiff("device or socket is not allowed");
            } elsif (-d _) {
                $type{$fn}= 'directory';
            } else {
                &unrepdiff("unknown file type ($!)");
            }
        }
        close(FIND); $? && subprocerr("find on $dir");
        close(GZIP) || &syserr("finish write to gzip pipe");
        &reapgzip;

        defined($c2= open(FIND,"-|")) || &syserr("fork for 2nd find");
        if (!$c2) {
            chdir($origdir) || &syserr("chdir to $origdir for 2nd find");
            exec('find','.','-print0'); &syserr("exec 2nd find");
        }
        $/= "\0";
        while (defined($fn= <FIND>)) {
            $fn =~ s/\0$//; $fn =~ s,^\./,,;
            next if defined($type{$fn});
            lstat("$origdir/$fn") || &syserr("cannot check orig file $origdir/$fn");
            if (-f _) {
                &warn("ignoring deletion of file $fn");
            } elsif (-d _) {
                &warn("ignoring deletion of directory $fn");
            } elsif (-l _) {
                &warn("ignoring deletion of symlink $fn");
            } else {
                &unrepdiff2('not a file, directory or link','nonexistent');
            }
        }
        close(FIND); $? && subprocerr("find on $dirname");

        &addfile("$basenamerev.diff.gz");

    }

    if ($sourcestyle =~ m/[prPR]/) {
        erasedir($origdir);
    }

    print("$progname: building $sourcepackage in $basenamerev.dsc\n")
        || &syserr("write building message");
    open(STDOUT,"> $basenamerev.dsc") || &syserr("create $basenamerev.dsc");
    &outputclose;

    if ($ur) {
        print(STDERR "$progname: unrepresentable changes to source\n")
            || &syserr("write error msg: $!");
        exit(1);
    }
    exit(0);

} else {

    $sourcestyle =~ y/X/p/;
    $sourcestyle =~ m/[pun]/ ||
        &usageerr("source handling style -s$sourcestyle not allowed with -b");

    @ARGV==1 || &usageerr("-x needs exactly one argument, the .dsc");
    $dsc= shift(@ARGV);
    $dsc= "./$dsc" unless $dsc =~ m:^/:;
    $dscdir= $dsc; $dscdir= "./$dscdir" unless $dsc =~ m,^/|^\./,;
    $dscdir =~ s,/[^/]+$,,;

    open(CDATA,"< $dsc") || &error("cannot open .dsc file $dsc: $!");
    &parsecdata('S',-1,"source control file $dsc");

    for $f (qw(Source Version Files)) {
        defined($fi{"S $f"}) ||
            &error("missing critical source control field $f");
    }

    $sourcepackage= $fi{'S Source'};
    $sourcepackage =~ m/[^-+.0-9a-z]/ &&
        &error("source package name contains illegal character \`$&'");
    $sourcepackage =~ m/^[0-9a-z]./ ||
        &error("source package name is too short or starts with non-alphanum");

    $version= $fi{'S Version'};
    $version =~ m/[^-+:.0-9a-zA-Z]/ &&
        &error("version number contains illegal character \`$&'");
    $version =~ s/^\d+://;
    if ($version =~ m/-([^-]+)$/) {
        $baseversion= $`; $revision= $1;
    } else {
        $baseversion= $version; $revision= '';
    }

    $files= $fi{'S Files'};
    for $file (split(/\n /,$files)) {
        next if $file eq '';
        $file =~ m/^([0-9a-f]{32})[ \t]+(\d+)[ \t]+([0-9a-zA-Z][-+:.,=0-9a-zA-Z_]+)$/
            || &error("Files field contains bad line \`$file'");
        ($md5sum{$3},$size{$3},$file) = ($1,$2,$3);
        &setfile(\$tarfile) if $file =~ m/\.tar\.gz$/;
        &setfile(\$difffile) if $file =~ m/\.diff\.gz$/;
    }

    $newdirectory= $sourcepackage.'-'.$baseversion;
    $expectprefix= $newdirectory; $expectprefix.= '.orig' if length($difffile);
    
    length($tarfile) || &error("no tarfile in Files field");
    checkstats($tarfile);
    checkstats($difffile) if length($difffile);

    checktarsane("$dscdir/$tarfile",$expectprefix);

    if (length($difffile)) {
        if (!$dirincluded{"$expectprefix/debian"}) {
            $mkdebian=1; $dirincluded{"$expectprefix/debian"}= 1;
        }
            
        &forkgzipread("$dscdir/$difffile");
        $/="\n";
        while (length($_=<GZIP>)) {
            s/\n$// || &error("diff is missing trailing newline");
            if (m/^--- /) {
                $fn= $';
                substr($fn,0,length($expectprefix)+1) eq "$expectprefix/" ||
                    &error("diff patches file ($fn) not in expected subdirectory");
                $fn =~ m/\.dpkg-orig$/ &&
                    &error("diff patches file with name ending .dpkg-orig");
                $dirname= $fn;
                $dirname =~ s,/[^/]+$,, && defined($dirincluded{$dirname}) ||
                    &error("diff patches file ($fn) whose directory does not appear".
                           " in tarfile");
                defined($notfileobject{$fn}) &&
                    &error("diff patches something which is not a plain file");
                $_= <GZIP>; s/\n$// ||
                    &error("diff finishes in middle of ---/+++ (line $.)");
                $_ eq '+++ '.$newdirectory.substr($fn,length($expectprefix)) ||
                    &error("line after --- for file $fn isn't as expected");
                $filepatched{$fn}++ && &error("diff patches file $fn twice");
            } elsif (!m/^[-+ \@]/) {
                &error("diff contains unknown line \`$_'");
            }
        }
        close(GZIP);
        
        &reapgzip;
    }

    print("$progname: extracting $sourcepackage in $newdirectory\n")
        || &syserr("write extracting message");
    
    &erasedir($newdirectory);
    &erasedir("$newdirectory.orig");

    extracttar("$dscdir/$tarfile",'.');
    
    if (length($difffile)) {
        rename($expectprefix,$newdirectory) ||
            &syserr("failed to rename newly-extracted $expectprefix to $newdirectory");

        if ($sourcestyle =~ m/u/) {
            extracttar("$dscdir/$tarfile",'.');
        } elsif ($sourcestyle =~ m/p/) {
            stat("$dscdir/$tarfile") ||
                &syserr("failed to stat \`$dscdir/$tarfile' to see if need to copy");
            ($dsctardev,$dsctarino) = stat _;
            $dumptar= $sourcepackage.'_'.$baseversion.'.orig.tar.gz';
            if (!stat($dumptar)) {
                $! == ENOENT || &syserr("failed to check destination \`$dumptar'".
                                        " to see if need to copy");
            } else {
                ($dumptardev,$dumptarino) = stat _;
                if ($dumptardev == $dsctardev && $dumptarino == $dsctarino) {
                    $dumptar= '';
                }
            }
            if (length($dumptar)) {
                system('cp','--',"$dscdir/$tarfile","$dumptar");
                $? && subprocerr("cp $dscdir/$tarfile to $dumptar");
            }
        }                

        if ($mkdebian) {
            mkdir("$newdirectory/debian",0777) ||
                &syserr("failed to create $newdirectory/debian subdirectory");
        }
        &forkgzipread("$dscdir/$difffile");
        defined($c2= fork) || &syserr("fork for patch");
        if (!$c2) {
            open(STDIN,"<&GZIP") || &syserr("reopen gzip for patch");
            chdir($newdirectory) || &syserr("chdir to $newdirectory for patch");
            exec('patch','-s','-t','-F','0','-N','-p1','-u',
                 '-V','never','-b','.dpkg-orig');
            &syserr("exec patch");
        }
        close(GZIP);
        $c2 == waitpid($c2,0) || &syserr("wait for patch");
        $? && subprocerr("patch");
        &reapgzip;

        for $fn (keys %filepatched) {
            $ftr= "$newdirectory/".substr($fn,length($expectprefix)+1).".dpkg-orig";
            unlink($ftr) || &syserr("remove patch backup file $ftr");
        }

        if (!(@s= lstat("$newdirectory/debian/rules"))) {
            $! == ENOENT || &syserr("cannot stat $newdirectory/debian/rules");
            &warn("$newdirectory/debian/rules does not exist");
        } elsif (-f _) {
            chmod($s[2] | 0111, "$newdirectory/debian/rules") ||
                &syserr("cannot make $newdirectory/debian/rules executable");
        } else {
            &warn("$newdirectory/debian/rules is not a plain file");
        }
    }

    $execmode= 0777 & ~umask;
    (@s= stat('.')) || &syserr("cannot stat \`.'");
    $dirmode= $execmode | ($s[2] & 02000);
    $plainmode= $execmode & ~0111;
    $fifomode= ($plainmode & 0222) | (($plainmode & 0222) << 1);
    for $fn (@filesinarchive) {
        $fn= substr($fn,length($expectprefix)+1);
        $fn= "$newdirectory/$fn";
        (@s= lstat($fn)) || &syserr("cannot stat extracted object \`$fn'");
        $mode= $s[2];
        if (-d _) {
            $newmode= $dirmode;
        } elsif (-f _) {
            $newmode= ($mode & 0111) ? $execmode : $plainmode;
        } elsif (-p _) {
            $newmode= $fifomode;
        } elsif (!-l _) {
            &internerr("unknown object \`$fn' after extract (mode ".
                       sprintf("0%o",$mode).")");
        }
        next if ($mode & 07777) == $newmode;
        chmod($newmode,$fn) ||
            &syserr(sprintf("cannot change mode of \`%s' to 0%o from 0%o",
                            $fn,$newmode,$mode));
    }
    exit(0);
}

sub checkstats {
    my ($f)= @_;
    my @s,$m;
    open(STDIN,"< $dscdir/$f") || &syserr("cannot read $dscdir/$f");
    (@s= stat(STDIN)) || &syserr("cannot fstat $dscdir/$f");
    $s[7] == $size{$f} || &error("file $f has size $s[7] instead of expected $size{$f}");
    $m= `md5sum`; $? && subprocerr("md5sum $f"); $m =~ s/\n$//;
    $m =~ m/^[0-9a-f]{32}$/ || &failure("md5sum of $f gave bad output \`$m'");
    $m eq $md5sum{$f} || &error("file $f has md5sum $m instead of expected $md5sum{$f}");
    open(STDIN,"</dev/null") || &syserr("reopen stdin from /dev/null");
}

sub erasedir {
    my ($dir) = @_;
    if (!lstat($dir)) {
        $! == ENOENT && return;
        &syserr("cannot stat directory $dir (before removal)");
    }
    system 'rm','-rf','--',$dir;
    $? && subprocerr("rm -rf $dir");
    if (!stat($dir)) {
        $! == ENOENT && return;
        &syserr("unable to check for removal of dir \`$dir'");
    }
    &failure("rm -rf failed to remove \`$dir'");
}

sub checktarsane {
    my ($tarfileread,$epfx) = @_;
    my $c2,$fn,$pname,$slash,$mode,$dirname,$type;

    &forkgzipread("$tarfileread");
    defined($c2= open(CPIO,"-|")) || &syserr("fork for cpio");
    if (!$c2) {
        open(STDIN,"<&GZIP") || &syserr("reopen gzip for cpio");
        &cpiostderr;
        exec('cpio','-0t'); &syserr("exec cpio");
    }
    $/= "\0";
    close(GZIP);
  file:
    while (defined($fn= <CPIO>)) {
        $fn =~ s/\0$//; $pname= $fn; $pname =~ y/ -~/?/c;
        if ($fn =~ m/\n/) {
            if (!@filesinarchive) {
                &error("first output from cpio -0t (from \`$tarfileread') ".
                       "contains newline - you probably have an out of ".
                       "date version of cpio.  2.4.2-2 is known to work");
            } else {
                &error("tarfile \`$tarfileread' contains object with".
                       " newline in its name ($pname)");
            }
        }
        $slash= substr($fn,length($epfx),1);
        (($slash eq '/' || $slash eq '') &&
         substr($fn,0,length($epfx)) eq $epfx) ||
             &error("tarfile \`$tarfileread' contains object ($pname) ".
                    "not in expected directory ($epfx)");
        $fn =~ m,/\.\./, &&
            &error("tarfile \`$tarfilread' contains object with".
                   " /../ in its name ($pname)");
        push(@filesinarchive,$fn);
    }
    close(CPIO); $? && subprocerr("cpio");
    
    $/= "\n";
    &reapgzip;
    &forkgzipread("$tarfileread");
    defined($c2= open(TAR,"-|")) || &syserr("fork for tar -t");
    if (!$c2) {
        $ENV{'LANG'}= 'C';
        open(STDIN,"<&GZIP") || &syserr("reopen gzip for tar -t");
        exec('tar','-vvtf','-'); &syserr("exec tar -vvtf -");
    }
    close(GZIP);
    $efix= 0;
  file:
    while (length($_= <TAR>)) {
        s/\n$//;
        m,^(\S{10})\s, ||
            &error("tarfile \`$tarfileread' contains unknown object ".
                   "listed by tar as \`$_'");
        $fn= $filesinarchive[$efix++]; $mode= $1;
        if ($mode =~ m/^l/) { $_ =~ s/ -\> .*//; }
        substr($_,length($_)-length($fn)-1) eq " $fn" ||
            &error("tarfile \`$tarfileread' contains unexpected object".
                   " listed by tar as \`$_', expected \`$fn'");
        $mode =~ s/^([-dpsl])// ||
            &error("tarfile \`$tarfileread' contains object \`$fn' with ".
                   "unknown or forbidden type \`".substr($_,0,1)."'");
        $fn =~ m/\.dpkg-orig$/ &&
            &error("tarfile \`$tarfileread' contains file with name ending .dpkg-orig");
        $type= $&;
        $mode =~ m/[sStT]/ && $type ne 'd' &&
            &error("tarfile \`$tarfileread' contains setuid, setgid".
                   " or sticky object \`$fn'");
        $fn eq "$epfx/debian" && $type ne 'd' &&
            &error("tarfile \`$tarfileread' contains object \`debian'".
                   " that isn't a directory");
        $fn =~ s,/$,, if $type eq 'd';
        $dirname= $fn;
        $dirname =~ s,/[^/]+$,, && !defined($dirincluded{$dirname}) &&
            &error("tarfile \`$tarfileread' contains object \`$fn' but its containing ".
                   "directory \`$dirname' does not precede it");
        $dirincluded{$fn}= 1 if $type eq 'd';
        $notfileobject{$fn}= 1 if $type ne '-';
    }
    close(TAR); $? && subprocerr("tar -t");
    &reapgzip;
}

sub extracttar {
    my ($tarfileread,$dirchdir) = @_;
    &forkgzipread("$tarfileread");
    defined($c2= fork) || &syserr("fork for cpio -i");
    if (!$c2) {
        chdir("$dirchdir") || &syserr("cannot chdir to \`$dirchdir' for tar extract");
        open(STDIN,"<&GZIP") || &syserr("reopen gzip for cpio -i");
        &cpiostderr;
        exec('cpio','-Hustar','-im','--no-preserve-owner'); &syserr("exec cpio -i");
    }
    close(GZIP);
    $c2 == waitpid($c2,0) || &syserr("wait for cpio -i");
    $? && subprocerr("cpio -i");
    &reapgzip;
}

sub cpiostderr {
    open(STDERR,"| egrep -v '^[0-9]+ blocks\$' >&2") ||
        &syserr("reopen stderr for cpio to grep out blocks message");
}

sub setfile {
    my ($varref)= @_;
    &error("repeated file type - files ".$$varref." and $file") if length($$varref);
    $$varref= $file;
}

sub checktype {
    if (!lstat("$origdir/$fn")) {
        &unrepdiff2("nonexistent",$type{$fn});
    } else {
        $v= eval("$_[0] _ ? 2 : 1"); $v || &internerr("checktype $@ ($_[0])");
        return 1 if $v == 2;
        &unrepdiff2("something else",$type{$fn});
    }
    return 0;
}

sub setopmode {
    defined($opmode) && &usageerr("only one of -x or -b allowed, and only once");
    $opmode= $_[0];
}

sub unrepdiff {
    print(STDERR "$progname: cannot represent change to $fn: $_[0]\n")
        || &syserr("write syserr unrep");
    $ur++;
}

sub unrepdiff2 {
    print(STDERR "$progname: cannot represent change to $fn:\n".
          "$progname:  new version is $_[1]\n".
          "$progname:  old version is $_[0]\n")
        || &syserr("write syserr unrep");
    $ur++;
}

sub forkgzipwrite {
#print STDERR "forkgzipwrite $_[0]\n";
    open(GZIPFILE,"> $_[0]") || &syserr("create file $_[0]");
    pipe(GZIPREAD,GZIP) || &syserr("pipe for gzip");
    defined($cgz= fork) || &syserr("fork for gzip");
    if (!$cgz) {
        open(STDIN,"<&GZIPREAD") || &syserr("reopen gzip pipe"); close(GZIPREAD);
        close(GZIP); open(STDOUT,">&GZIPFILE") || &syserr("reopen tar.gz");
        exec('gzip','-9'); &syserr("exec gzip");
    }
    close(GZIPREAD);
    $gzipsigpipeok= 0;
}

sub forkgzipread {
#print STDERR "forkgzipread $_[0]\n";
    open(GZIPFILE,"< $_[0]") || &syserr("read file $_[0]");
    pipe(GZIP,GZIPWRITE) || &syserr("pipe for gunzip");
    defined($cgz= fork) || &syserr("fork for gunzip");
    if (!$cgz) {
        open(STDOUT,">&GZIPWRITE") || &syserr("reopen gunzip pipe"); close(GZIPWRITE);
        close(GZIP); open(STDIN,"<&GZIPFILE") || &syserr("reopen input file");
        exec('gunzip'); &syserr("exec gunzip");
    }
    close(GZIPWRITE);
    $gzipsigpipeok= 1;
}

sub reapgzip {
#print STDERR "reapgzip $_[0]\n";
    $cgz == waitpid($cgz,0) || &syserr("wait for gzip");
    !$? || ($gzipsigpipeok && WIFSIGNALED($?) && WTERMSIG($?)==SIGPIPE) ||
        subprocerr("gzip");
    close(GZIPFILE);
}

sub addfile {
    my ($filename)= @_;
    stat($filename) || &syserr("could not stat output file \`$filename'");
    $size= (stat _)[7];
    my $md5sum= `md5sum <$filename`;
    $? && &subprocerr("md5sum $filename");
    $md5sum =~ s/^([0-9a-f]{32})\n$/$1/ || &failure("md5sum gave bogus output \`$_'");
    $f{'Files'}.= "\n $md5sum $size $filename";
}