mknod -m 0666 /dev/null c 1 3: Glibc needs a null device to compile properly. All other devices will be created in the next section. touch /etc/ld.so.conf One of the final steps of the Glibc installation is running ldconfig to update the dynamic loader cache. If this file doesn't exist, the installation will abort with an error that it can't read the file, so we simply create an empty file (the empty file will have Glibc default to using /lib and /usr/lib which is fine). sed 's%\$(PERL)%/usr/bin/perl%' malloc/Makefile > tmp~: This sed command searches through malloc/Makefile and converts all occurances of $(PERL) to /usr/bin/perl. The output is then written to the file tmp~. This is done because Glibc can't autodetect perl since it hasn't been installed yet. mv tmp~ malloc/Makefile: The file tmp~ is now moved back to malloc/Makefile. We do this because when using sed, we can't write straight back to this file so we need to use a temporary file in between. sed 's/root/0' login/Makefile > tmp~: This sed command replaces all occurances of root in login/Makefile with 0. This is because as we don't have glibc on the LFS system yet, usernames can't be resolved to their user id's. Therefore, we replace the username root with the id 0. mv tmp~ login/Makefile: As above, we are using a temporary file (tmp~) to store the edited Makefile and then copying it back over the original. --enable-add-ons: This enables the add-on that we install with Glibc: linuxthreads --libexecdir=/usr/bin: This will cause the pt_chown program to be installed in the /usr/bin directory. sed 's/cross-compiling = yes/cross-compiling = no/' config.make > config.make~: This time, we're replacing cross-compiling = yes with cross-compiling = no. We do this because we are only building for our own system. Cross-compiling is used, for instance, to build a package for an Apple Power PC on an Intel system. The reason Glibc thinks we're cross-compiling is that it can't compile a test program to determine this, so it automatically defaults to a cross-compiler. The reason for the failed program is because Glibc hasn't been installed yet. mv config.make~ config.make: Again, we are moving the temporary file over the original. exec /bin/bash:This command will start a new bash shell which will replace the current shell. This is done to get rid of the "I have no name!" message in the command prompt, which was caused by bash's inability to resolve a userid to a username (which in turn was caused by the missing Glibc installation).