polystrap/default/root/usr/bin/ldd
2011-06-22 09:50:36 +02:00

201 lines
4.4 KiB
Perl
Executable file

#!/usr/bin/perl
# fakeldd
#
# Replacement for ldd with usage of objdump
#
# (c) 2003-2010 Piotr Roszatycki <dexter@debian.org>, LGPL
use strict;
my @Libs = ();
my %Libs = ();
my $Status = 0;
my $Dynamic = 0;
my $Format = '';
my $Ldsodir = "/lib";
my @Ld_Library_Path = qw(/usr/lib /lib /usr/lib32 /lib32 /usr/lib64 /lib64);
sub ldso {
my ($lib) = @_;
return if $Libs{$lib};
my $path;
if ($lib =~ /^\//) {
$path = $lib;
}
else {
foreach my $dir (@Ld_Library_Path) {
next unless -f "$dir/$lib";
my $badformat = 0;
local *PIPE;
open PIPE, "objdump -p '$dir/$lib' 2>/dev/null |";
while (my $line = <PIPE>) {
if ($line =~ /file format (\S*)$/) {
$badformat = 1 unless $1 eq $Format;
last;
}
}
close PIPE;
next if $badformat;
$path = "$dir/$lib";
last;
}
}
push @Libs, $lib;
if (-f $path) {
$Libs{$lib} = $path;
objdump($path);
}
}
sub objdump {
my (@files) = @_;
foreach my $file (@files) {
local *PIPE;
open PIPE, "objdump -p '$file' 2>/dev/null |";
while (my $line = <PIPE>) {
$line =~ s/^\s+//;
if ($line =~ /file format (\S*)$/) {
if (not $Format) {
$Format = $1;
if ($^O eq 'linux') {
if ($Format =~ /^elf64-/) {
push @Libs, 'linux-vdso.so.1';
$Libs{'linux-vdso.so.1'} = '';
}
else {
push @Libs, 'linux-gate.so.1';
$Libs{'linux-gate.so.1'} = '';
}
}
foreach my $lib (split /:/, $ENV{LD_PRELOAD}||'') {
ldso($lib);
}
}
else {
next unless $Format eq $1;
}
}
if (not $Dynamic and $line =~ /^Dynamic Section:/) {
$Dynamic = 1;
}
next unless $line =~ /^ \s* NEEDED \s+ (.*) \s* $/x;
my $needed = $1;
if ($needed =~ /^ld(-linux)?(\.|-)/) {
$needed = "$Ldsodir/$needed";
}
ldso($needed);
}
close PIPE;
}
}
sub load_ldsoconf {
my ($file) = @_;
local *FH;
open FH, $file;
while (my $line = <FH>) {
chomp $line;
$line =~ s/#.*//;
next if $line =~ /^\s*$/;
if ($line =~ /^include\s+(.*)\s*/) {
my $include = $1;
foreach my $incfile (glob $include) {
load_ldsoconf($incfile);
}
next;
}
unshift @Ld_Library_Path, $line;
}
close FH;
}
MAIN: {
my @args = @ARGV;
if (not @args) {
print STDERR "fakeldd: missing file arguments\n";
exit 1;
}
if (not `which objdump`) {
print STDERR "fakeldd: objdump: command not found: install binutils package\n";
exit 1;
}
load_ldsoconf('/etc/ld.so.conf');
unshift @Ld_Library_Path, split(/:/, $ENV{LD_LIBRARY_PATH}||'');
while ($args[0] =~ /^-/) {
my $arg = $args[0];
shift @ARGV;
last if $arg eq "--";
}
foreach my $file (@args) {
%Libs = ();
$Dynamic = 0;
if (@args > 1) {
print "$file:\n";
}
if (not -f $file) {
print STDERR "ldd: $file: No such file or directory\n";
$Status = 1;
next;
}
objdump($file);
if ($Dynamic == 0) {
print "\tnot a dynamic executable\n";
$Status = 1;
}
elsif (scalar %Libs eq "0") {
print "\tstatically linked\n";
}
my $address = '0x' . '0' x ($Format =~ /^elf64-/ ? 16 : 8);
foreach my $lib (@Libs) {
if ($lib =~ /^\//) {
printf "\t%s (%s)\n", $lib, $address;
}
elsif (defined $Libs{$lib}) {
printf "\t%s => %s (%s)\n", $lib, $Libs{$lib}, $address;
}
else {
printf "\t%s => not found\n", $lib;
}
}
}
}
END {
$? = $Status;
}