The GNU C Library Reference Manual is the definitive reference work for the GNU Project version of all the ISO C standard library and other standard functions. For printing purposes, it has been split into two stand-alone volumes.

A comprehensive guide to implementing the standard C libraries which are both POSIX & OPEN/X compliant, Fundamental Applications contains the most commonly used functions, such as: opening, reading, and closing files; screen I/O; performing math; character and string manipulation; and memory allocation. Contains code examples and usage recommendations. Every programmer, from first year students to experienced programmers, will find this book useful.

• Error reporting
• Virtual memory allocation and paging
• Character handling
• String and array utilities
• Character set handling
• Locales and internationalization
• Mathematics and arithmetic functions
• Date and time
• Message translation
• Searching and sorting
• Pattern matching
• Basic program/system interface
• Overview of input/output
• Debugging support
• Streams and input/output
• Summary of library facilities

The GNU C Library supports the features of popular Unix variants (including BSD and System V) when no conflict occurs with ISO C and POSIX standards. Different compatibility modes (selectable when you compile an application) allow peaceful coexistence of the different varieties of Unix. Highly portable, you can build libraries for any supported system with just configure & make.

The GNU C Library is fully internationalized. The messages have been translated from American English into Brazilian Portuguese, British English, Chinese, Czech, Danish, Dutch, French, Galician, German, Greek, Italian, Japanese, Korean, Norwegian, Polish, Slovak, Spanish, Swedish, and Turkish.

This reference manual:

• Gives advice on how to write programs to work under multiple C dialects.
• Contains an alphabetical listing of functions and other library symbols, and which standards each belongs to.
• Identifies which features belong to which standards, enabling identification of possible nonportability problems in advance.
• Includes overviews of the ISO C and POSIX standards, including the System V and Berkeley Unix implementations.

• ISO C 99
• ISO C Standard
• POSIX.1c 1d 1j
• POSIX.2
• GNU extensions
• 4.2, 4.3, 4.4 BSD
• Unix98
• SVID
• SunOS
• System V Unix
• XSI (X/Open System Interface)