To install the library and its header files, and the Info files of the
manual, type env LANGUAGE=C LC_ALL=C make install. This will
build things, if necessary, before installing them; however, you should
still compile everything first. If you are installing the GNU C Library as your
primary C library, we recommend that you shut the system down to
single-user mode first, and reboot afterward. This minimizes the risk
of breaking things when the library changes out from underneath.
‘make install’ will do the entire job of upgrading from a previous installation of the GNU C Library version 2.x. There may sometimes be headers left behind from the previous installation, but those are generally harmless. If you want to avoid leaving headers behind you can do things in the following order.
You must first build the library (‘make’), optionally check it (‘make check’), switch the include directories and then install (‘make install’). The steps must be done in this order. Not moving the directory before install will result in an unusable mixture of header files from both libraries, but configuring, building, and checking the library requires the ability to compile and run programs against the old library. The new /usr/include, after switching the include directories and before installing the library should contain the Linux headers, but nothing else. If you do this, you will need to restore any headers from libraries other than the GNU C Library yourself after installing the library.
You can install the GNU C Library somewhere other than where you configured it to go
by setting the install_root variable on the command line for
‘make install’. The value of this variable is prepended to all the
paths for installation. This is useful when setting up a chroot
environment or preparing a binary distribution. The directory should be
specified with an absolute file name.
The GNU C Library includes a daemon called nscd, which you
may or may not want to run. nscd caches name service lookups; it
can dramatically improve performance with NIS+, and may help with DNS as
well.
One auxiliary program, /usr/libexec/pt_chown, is installed setuid
root. This program is invoked by the grantpt function; it
sets the permissions on a pseudoterminal so it can be used by the
calling process. This means programs like xterm and
screen do not have to be setuid to get a pty. (There may be
other reasons why they need privileges.) If you are using a
Linux kernel with the devptsfs or devfs filesystems
providing pty slaves, you don't need this program; otherwise you do.
The source for pt_chown is in login/programs/pt_chown.c.
After installation you might want to configure the timezone and locale
installation of your system. The GNU C Library comes with a locale
database which gets configured with localedef. For example, to
set up a German locale with name de_DE, simply issue the command
‘localedef -i de_DE -f ISO-8859-1 de_DE’. To configure all locales
that are supported by the GNU C Library, you can issue from your build directory the
command ‘make localedata/install-locales’.
To configure the locally used timezone, set the TZ environment
variable. The script tzselect helps you to select the right value.
As an example, for Germany, tzselect would tell you to use
‘TZ='Europe/Berlin'’. For a system wide installation (the given
paths are for an installation with ‘--prefix=/usr’), link the
timezone file which is in /usr/share/zoneinfo to the file
/etc/localtime. For Germany, you might execute ‘ln -s
/usr/share/zoneinfo/Europe/Berlin /etc/localtime’.