Standard Libraries93
3.9Standard Libraries
In addition to the compiler, assembler, linker and other tools, you also need standard library
files. All Linux distributions come with the GNU C library which is installed as
glibc
. How-
ever, when you are building your development environment, you may need to get the library in
source code format and install the latest version. You may also need the library in source code
format in order to cross compile it when you are building a cross-compilation environment. The
standard GNU C library provides functions for the following major areas.
•Memory management
•Error handling
•Character handling
•Strings and arrays
•Locales and international specific things, like character handling and date and time
specific functions
•Searching
•Sorting
•Pattern matching
•Input and output
•File system support
•Pipes
•Fifos
•Sockets
•Terminal I/O
•Mathematics functions
•Date and time functions
•Signal and exception handling
•Process management
•Job control
•User and groups
•System related tasks
Information about
glibc
is available on http://www.gnu.org/software/libc/libc.html.
You can download it from ftp://ftp.gnu.org/gnu/glibc/ where you can find the latest as well as old
versions. The current version at the time of writing this book is 2.2.5.
After downloading the library, you have to untar it. For the sake of this book, I untarred the
library file in
/opt
directory. The following
tar
command extracts library files in
/opt/
glibc-2.2.5
directory.
tar zxvf glibc-2.2.5.tar.gz
Now you have to extract any other components or add-ons of the library. I have added one
component, Linux threads. File
glibc-linuxthreads-2.2.5.tar.gz
can also be