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<?xml version="1.0" encoding="ISO-8859-1"?>
<!DOCTYPE sect1 PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN"
"http://www.oasis-open.org/docbook/xml/4.5/docbookx.dtd" [
<!ENTITY % general-entities SYSTEM "../general.ent">
%general-entities;
]>
<sect1 id="ch-system-strippingagain">
<?dbhtml filename="strippingagain.html"?>
<title>Stripping Again</title>
<para>This section is optional. If the intended user is not a
programmer and does not plan to do
any debugging on the system software, the system size can be decreased
by about 2 GB by removing the debugging symbols from binaries and
libraries. This causes no inconvenience other than not being able to
debug the software fully anymore.</para>
<para>Most people who use the commands mentioned below do not
experience any difficulties. However, it is easy to make a typo and
render the new system unusable, so before running the
<command>strip</command> commands, it is a good idea to make a
backup of the LFS system in its current state.</para>
<para>The debugging symbols for selected libraries are placed
in separate files. This debugging information is needed if running
regression tests that use <ulink
url='&blfs-book;/general/valgrind.html'>valgrind</ulink> or <ulink
url='&blfs-book;/general/gdb.html'>gdb</ulink> later in BLFS.
</para>
<para>Note that <command>strip</command> will overwrite the binary or library
file it is processing. This may crash the processes using code or data from
the file. If the process running <command>strip</command> itself is
affected, the binary or library being stripped may be destroyed. This may
make the system completely unusable. To avoid it, we'll copy some libraries
and binaries into <filename class="directory">/tmp</filename>, strip them
there, and install them back with the <command>install</command> command.
Read the related entry in <xref linkend="pkgmgmt-upgrade-issues"/> for the
rationale to use the <command>install</command> command here.</para>
<note><para>The ELF loader's name is ld-linux-x86-64.so.2 on 64-bit systems
and ld-linux.so.2 on 32-bit systems. The contruct below selects the
correct name for the current architecture.</para></note>
<!-- also of interest are libgfortan, libgo, libgomp, and libobjc from GCC -->
<!--<screen><userinput>save_lib="ld-2.25.so libc-2.25.so libpthread-2.25.so libthread_db-1.0.so"-->
<screen><userinput>save_usrlib="$(cd /usr/lib; ls ld_linux*)
libc.so.6
libthread_db.so.1
libquadmath.so.&libquadmath-version;
libstdc++.so.&libstdcpp-version;
libitm.so.&libitm-version;
libatomic.so.&libatomic-version;"
cd /usr/lib
for LIB in $save_usrlib; do
objcopy --only-keep-debug $LIB $LIB.dbg
cp $LIB /tmp/$LIB
strip --strip-unneeded /tmp/$LIB
objcopy --add-gnu-debuglink=$LIB.dbg /tmp/$LIB
install -vm755 /tmp/$LIB /usr/lib
rm /tmp/$LIB
done
online_usrbin="bash find strip"
online_usrlib="libbfd-&binutils-version;.so
libhistory.so.&readline-version;
libncursesw.so.&ncurses-version;
libm.so.6
libreadline.so.&readline-version;
libz.so.&zlib-version;
$(cd /usr/lib; find libnss*.so* -type f)"
for BIN in $online_usrbin; do
cp /usr/bin/$BIN /tmp/$BIN
strip --strip-unneeded /tmp/$BIN
install -vm755 /tmp/$BIN /usr/bin
rm /tmp/$BIN
done
for LIB in $online_usrlib; do
cp /usr/lib/$LIB /tmp/$LIB
strip --strip-unneeded /tmp/$LIB
install -vm755 /tmp/$LIB /usr/lib
rm /tmp/$LIB
done
for i in $(find /usr/lib -type f -name \*.so* ! -name \*dbg) \
$(find /usr/lib -type f -name \*.a) \
$(find /usr/{bin,sbin,libexec} -type f); do
case "$online_usrbin $online_usrlib $save_usrlib" in
*$(basename $i)* )
;;
* ) strip --strip-unneeded $i
;;
esac
done
unset BIN LIB save_usrlib online_usrbin online_usrlib
</userinput></screen>
<para>A large number of files will be reported as having their file
format not recognized. These warnings can be safely ignored. These
warnings indicate that those files are scripts instead of
binaries.</para>
</sect1>
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