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 This is 'The GNU C Library Reference Manual', for Version 2.17 of the
 GNU C Library.


* Introduction                 Purpose of the GNU C Library.
* Error Reporting              How library functions report errors.
* Memory                       Allocating virtual memory and controlling
* Character Handling           Character testing and conversion functions.
* String and Array Utilities   Utilities for copying and comparing strings
                                    and arrays.
* Character Set Handling       Support for extended character sets.
* Locales                      The country and language can affect the
                                    behavior of library functions.
* Message Translation          How to make the program speak the user's
* Searching and Sorting        General searching and sorting functions.
* Pattern Matching             Matching shell "globs" and regular
* I/O Overview                 Introduction to the I/O facilities.
* I/O on Streams               High-level, portable I/O facilities.
* Low-Level I/O                Low-level, less portable I/O.
* File System Interface        Functions for manipulating files.
* Pipes and FIFOs              A simple interprocess communication
* Sockets                      A more complicated IPC mechanism, with
                                    networking support.
* Low-Level Terminal Interface How to change the characteristics of a
                                    terminal device.
* Syslog                       System logging and messaging.
* Mathematics                  Math functions, useful constants, random
* Arithmetic                   Low level arithmetic functions.
* Date and Time                Functions for getting the date and time and
                                    formatting them nicely.
* Resource Usage And Limitation Functions for examining resource usage and
                                    getting and setting limits.
* Non-Local Exits              Jumping out of nested function calls.
* Signal Handling              How to send, block, and handle signals.
* Program Basics               Writing the beginning and end of your
* Processes                    How to create processes and run other
* Inter-Process Communication  All about inter-process communication.
* Job Control                  All about process groups and sessions.
* Name Service Switch          Accessing system databases.
* Users and Groups             How users are identified and classified.
* System Management            Controlling the system and getting
                                    information about it.
* System Configuration         Parameters describing operating system
* Cryptographic Functions      DES encryption and password handling.
* Debugging Support            Functions to help debugging applications.
* POSIX Threads                POSIX Threads.
* Internal Probes              Probes to monitor libc internal behavior.
* Language Features            C language features provided by the library.
* Library Summary              A summary showing the syntax, header file,
                                    and derivation of each library feature.
* Installation                 How to install the GNU C Library.
* Maintenance                  How to enhance and port the GNU C Library.
* Platform                     Describe all platform-specific facilities
* Contributors                 Who wrote what parts of the GNU C Library.
* Free Manuals                 Free Software Needs Free Documentation.
* Copying                      The GNU Lesser General Public License says
                                   how you can copy and share the GNU C Library.
* Documentation License        This manual is under the GNU Free
                                   Documentation License.
* Concept Index                Index of concepts and names.
* Type Index                   Index of types and type qualifiers.
* Function Index               Index of functions and function-like macros.
* Variable Index               Index of variables and variable-like macros.
* File Index                   Index of programs and files.
  -- The Detailed Node Listing --
* Getting Started             What this manual is for and how to use it.
* Standards and Portability   Standards and sources upon which the GNU
                                  C library is based.
* Using the Library           Some practical uses for the library.
* Roadmap to the Manual       Overview of the remaining chapters in
                                  this manual.
 Standards and Portability
* ISO C                       The international standard for the C
                                  programming language.
* POSIX                       The ISO/IEC 9945 (aka IEEE 1003) standards
                                  for operating systems.
* Berkeley Unix               BSD and SunOS.
* SVID                        The System V Interface Description.
* XPG                         The X/Open Portability Guide.
* POSIX Safety Concepts       Safety concepts from POSIX.
* Unsafe Features             Features that make functions unsafe.
* Conditionally Safe Features Features that make functions unsafe
                                  in the absence of workarounds.
* Other Safety Remarks        Additional safety features and remarks.
 Using the Library
* Header Files                How to include the header files in your
* Macro Definitions           Some functions in the library may really
                                  be implemented as macros.
* Reserved Names              The C standard reserves some names for
                                  the library, and some for users.
* Feature Test Macros         How to control what names are defined.
 Error Reporting
* Checking for Errors         How errors are reported by library functions.
* Error Codes                 Error code macros; all of these expand
                                  into integer constant values.
* Error Messages              Mapping error codes onto error messages.
* Memory Concepts             An introduction to concepts and terminology.
* Memory Allocation           Allocating storage for your program data
* Resizing the Data Segment   'brk', 'sbrk'
* Locking Pages               Preventing page faults
 Memory Allocation
* Memory Allocation and C     How to get different kinds of allocation in C.
* Unconstrained Allocation    The 'malloc' facility allows fully general
 		 		 dynamic allocation.
* Allocation Debugging        Finding memory leaks and not freed memory.
* Obstacks                    Obstacks are less general than malloc
 				 but more efficient and convenient.
* Variable Size Automatic     Allocation of variable-sized blocks
 				 of automatic storage that are freed when the
 				 calling function returns.
 Unconstrained Allocation
* Basic Allocation            Simple use of 'malloc'.
* Malloc Examples             Examples of 'malloc'.  'xmalloc'.
* Freeing after Malloc        Use 'free' to free a block you
 				 got with 'malloc'.
* Changing Block Size         Use 'realloc' to make a block
 				 bigger or smaller.
* Allocating Cleared Space    Use 'calloc' to allocate a
 				 block and clear it.
* Efficiency and Malloc       Efficiency considerations in use of
 				 these functions.
* Aligned Memory Blocks       Allocating specially aligned memory.
* Malloc Tunable Parameters   Use 'mallopt' to adjust allocation
* Heap Consistency Checking   Automatic checking for errors.
* Hooks for Malloc            You can use these hooks for debugging
 				 programs that use 'malloc'.
* Statistics of Malloc        Getting information about how much
 				 memory your program is using.
* Summary of Malloc           Summary of 'malloc' and related functions.
 Allocation Debugging
* Tracing malloc               How to install the tracing functionality.
* Using the Memory Debugger    Example programs excerpts.
* Tips for the Memory Debugger Some more or less clever ideas.
* Interpreting the traces      What do all these lines mean?
* Creating Obstacks           How to declare an obstack in your program.
* Preparing for Obstacks      Preparations needed before you can
 				 use obstacks.
* Allocation in an Obstack    Allocating objects in an obstack.
* Freeing Obstack Objects     Freeing objects in an obstack.
* Obstack Functions           The obstack functions are both
 				 functions and macros.
* Growing Objects             Making an object bigger by stages.
* Extra Fast Growing          Extra-high-efficiency (though more
 				 complicated) growing objects.
* Status of an Obstack        Inquiries about the status of an obstack.
* Obstacks Data Alignment     Controlling alignment of objects in obstacks.
* Obstack Chunks              How obstacks obtain and release chunks;
 				 efficiency considerations.
* Summary of Obstacks
 Variable Size Automatic
* Alloca Example              Example of using 'alloca'.
* Advantages of Alloca        Reasons to use 'alloca'.
* Disadvantages of Alloca     Reasons to avoid 'alloca'.
* GNU C Variable-Size Arrays  Only in GNU C, here is an alternative
 				 method of allocating dynamically and
 				 freeing automatically.
 Locking Pages
* Why Lock Pages                Reasons to read this section.
* Locked Memory Details         Everything you need to know locked
* Page Lock Functions           Here's how to do it.
 Character Handling
* Classification of Characters       Testing whether characters are
 			                letters, digits, punctuation, etc.
* Case Conversion                    Case mapping, and the like.
* Classification of Wide Characters  Character class determination for
                                         wide characters.
* Using Wide Char Classes            Notes on using the wide character
* Wide Character Case Conversion     Mapping of wide characters.
 String and Array Utilities
* Representation of Strings   Introduction to basic concepts.
* String/Array Conventions    Whether to use a string function or an
 				 arbitrary array function.
* String Length               Determining the length of a string.
* Copying and Concatenation   Functions to copy the contents of strings
 				 and arrays.
* String/Array Comparison     Functions for byte-wise and character-wise
* Collation Functions         Functions for collating strings.
* Search Functions            Searching for a specific element or substring.
* Finding Tokens in a String  Splitting a string into tokens by looking
 				 for delimiters.
* strfry                      Function for flash-cooking a string.
* Trivial Encryption          Obscuring data.
* Encode Binary Data          Encoding and Decoding of Binary Data.
* Argz and Envz Vectors       Null-separated string vectors.
 Argz and Envz Vectors
* Argz Functions              Operations on argz vectors.
* Envz Functions              Additional operations on environment vectors.
 Character Set Handling
* Extended Char Intro              Introduction to Extended Characters.
* Charset Function Overview        Overview about Character Handling
* Restartable multibyte conversion Restartable multibyte conversion
* Non-reentrant Conversion         Non-reentrant Conversion Function.
* Generic Charset Conversion       Generic Charset Conversion.
 Restartable multibyte conversion
* Selecting the Conversion     Selecting the conversion and its properties.
* Keeping the state            Representing the state of the conversion.
* Converting a Character       Converting Single Characters.
* Converting Strings           Converting Multibyte and Wide Character
* Multibyte Conversion Example A Complete Multibyte Conversion Example.
 Non-reentrant Conversion
* Non-reentrant Character Conversion  Non-reentrant Conversion of Single
* Non-reentrant String Conversion     Non-reentrant Conversion of Strings.
* Shift State                         States in Non-reentrant Functions.
 Generic Charset Conversion
* Generic Conversion Interface    Generic Character Set Conversion Interface.
* iconv Examples                  A complete 'iconv' example.
* Other iconv Implementations     Some Details about other 'iconv'
* glibc iconv Implementation      The 'iconv' Implementation in the GNU C
* Effects of Locale           Actions affected by the choice of
* Choosing Locale             How the user specifies a locale.
* Locale Categories           Different purposes for which you can
                                  select a locale.
* Setting the Locale          How a program specifies the locale
                                  with library functions.
* Standard Locales            Locale names available on all systems.
* Locale Names                Format of system-specific locale names.
* Locale Information          How to access the information for the locale.
* Formatting Numbers          A dedicated function to format numbers.
* Yes-or-No Questions         Check a Response against the locale.
 Locale Information
* The Lame Way to Locale Data   ISO C's 'localeconv'.
* The Elegant and Fast Way      X/Open's 'nl_langinfo'.
 The Lame Way to Locale Data
* General Numeric             Parameters for formatting numbers and
                                  currency amounts.
* Currency Symbol             How to print the symbol that identifies an
                                  amount of money (e.g. '$').
* Sign of Money Amount        How to print the (positive or negative) sign
                                  for a monetary amount, if one exists.
 Message Translation
* Message catalogs a la X/Open  The 'catgets' family of functions.
* The Uniforum approach         The 'gettext' family of functions.
 Message catalogs a la X/Open
* The catgets Functions      The 'catgets' function family.
* The message catalog files  Format of the message catalog files.
* The gencat program         How to generate message catalogs files which
                                 can be used by the functions.
* Common Usage               How to use the 'catgets' interface.
 The Uniforum approach
* Message catalogs with gettext  The 'gettext' family of functions.
* Helper programs for gettext    Programs to handle message catalogs
                                     for 'gettext'.
 Message catalogs with gettext
* Translation with gettext       What has to be done to translate a message.
* Locating gettext catalog       How to determine which catalog to be used.
* Advanced gettext functions     Additional functions for more complicated
* Charset conversion in gettext  How to specify the output character set
                                     'gettext' uses.
* GUI program problems           How to use 'gettext' in GUI programs.
* Using gettextized software     The possibilities of the user to influence
                                     the way 'gettext' works.
 Searching and Sorting
* Comparison Functions        Defining how to compare two objects.
 				 Since the sort and search facilities
                                  are general, you have to specify the
* Array Search Function       The 'bsearch' function.
* Array Sort Function         The 'qsort' function.
* Search/Sort Example         An example program.
* Hash Search Function        The 'hsearch' function.
* Tree Search Function        The 'tsearch' function.
 Pattern Matching
* Wildcard Matching    Matching a wildcard pattern against a single string.
* Globbing             Finding the files that match a wildcard pattern.
* Regular Expressions  Matching regular expressions against strings.
* Word Expansion       Expanding shell variables, nested commands,
 			    arithmetic, and wildcards.
 			    This is what the shell does with shell commands.
* Calling Glob             Basic use of 'glob'.
* Flags for Globbing       Flags that enable various options in 'glob'.
* More Flags for Globbing  GNU specific extensions to 'glob'.
 Regular Expressions
* POSIX Regexp Compilation    Using 'regcomp' to prepare to match.
* Flags for POSIX Regexps     Syntax variations for 'regcomp'.
* Matching POSIX Regexps      Using 'regexec' to match the compiled
 				   pattern that you get from 'regcomp'.
* Regexp Subexpressions       Finding which parts of the string were matched.
* Subexpression Complications Find points of which parts were matched.
* Regexp Cleanup              Freeing storage; reporting errors.
 Word Expansion
* Expansion Stages            What word expansion does to a string.
* Calling Wordexp             How to call 'wordexp'.
* Flags for Wordexp           Options you can enable in 'wordexp'.
* Wordexp Example             A sample program that does word expansion.
* Tilde Expansion             Details of how tilde expansion works.
* Variable Substitution       Different types of variable substitution.
 I/O Overview
* I/O Concepts       Some basic information and terminology.
* File Names         How to refer to a file.
 I/O Concepts
* Streams and File Descriptors    The GNU C Library provides two ways
 			             to access the contents of files.
* File Position                   The number of bytes from the
                                      beginning of the file.
 File Names
* Directories                 Directories contain entries for files.
* File Name Resolution        A file name specifies how to look up a file.
* File Name Errors            Error conditions relating to file names.
* File Name Portability       File name portability and syntax issues.
 I/O on Streams
* Streams                     About the data type representing a stream.
* Standard Streams            Streams to the standard input and output
 				 devices are created for you.
* Opening Streams             How to create a stream to talk to a file.
* Closing Streams             Close a stream when you are finished with it.
* Streams and Threads         Issues with streams in threaded programs.
* Streams and I18N            Streams in internationalized applications.
* Simple Output               Unformatted output by characters and lines.
* Character Input             Unformatted input by characters and words.
* Line Input                  Reading a line or a record from a stream.
* Unreading                   Peeking ahead/pushing back input just read.
* Block Input/Output          Input and output operations on blocks of data.
* Formatted Output            'printf' and related functions.
* Customizing Printf          You can define new conversion specifiers for
 				 'printf' and friends.
* Formatted Input             'scanf' and related functions.
* EOF and Errors              How you can tell if an I/O error happens.
* Error Recovery              What you can do about errors.
* Binary Streams              Some systems distinguish between text files
 				 and binary files.
* File Positioning            About random-access streams.
* Portable Positioning        Random access on peculiar ISO C systems.
* Stream Buffering            How to control buffering of streams.
* Other Kinds of Streams      Streams that do not necessarily correspond
 				 to an open file.
* Formatted Messages          Print strictly formatted messages.
* Unreading Idea              An explanation of unreading with pictures.
* How Unread                  How to call 'ungetc' to do unreading.
 Formatted Output
* Formatted Output Basics     Some examples to get you started.
* Output Conversion Syntax    General syntax of conversion
* Table of Output Conversions Summary of output conversions and
 				 what they do.
* Integer Conversions         Details about formatting of integers.
* Floating-Point Conversions  Details about formatting of
 				 floating-point numbers.
* Other Output Conversions    Details about formatting of strings,
 				 characters, pointers, and the like.
* Formatted Output Functions  Descriptions of the actual functions.
* Dynamic Output              Functions that allocate memory for the output.
* Variable Arguments Output   'vprintf' and friends.
* Parsing a Template String   What kinds of args does a given template
 				 call for?
* Example of Parsing          Sample program using 'parse_printf_format'.
 Customizing Printf
* Registering New Conversions         Using 'register_printf_function'
 					 to register a new output conversion.
* Conversion Specifier Options        The handler must be able to get
 					 the options specified in the
 					 template when it is called.
* Defining the Output Handler         Defining the handler and arginfo
 					 functions that are passed as arguments
 					 to 'register_printf_function'.
* Printf Extension Example            How to define a 'printf'
 					 handler function.
* Predefined Printf Handlers          Predefined 'printf' handlers.
 Formatted Input
* Formatted Input Basics      Some basics to get you started.
* Input Conversion Syntax     Syntax of conversion specifications.
* Table of Input Conversions  Summary of input conversions and what they do.
* Numeric Input Conversions   Details of conversions for reading numbers.
* String Input Conversions    Details of conversions for reading strings.
* Dynamic String Input        String conversions that 'malloc' the buffer.
* Other Input Conversions     Details of miscellaneous other conversions.
* Formatted Input Functions   Descriptions of the actual functions.
* Variable Arguments Input    'vscanf' and friends.
 Stream Buffering
* Buffering Concepts          Terminology is defined here.
* Flushing Buffers            How to ensure that output buffers are flushed.
* Controlling Buffering       How to specify what kind of buffering to use.
 Other Kinds of Streams
* String Streams              Streams that get data from or put data in
 				 a string or memory buffer.
* Custom Streams              Defining your own streams with an arbitrary
 				 input data source and/or output data sink.
 Custom Streams
* Streams and Cookies         The "cookie" records where to fetch or
 				 store data that is read or written.
* Hook Functions              How you should define the four "hook
 				 functions" that a custom stream needs.
 Formatted Messages
* Printing Formatted Messages   The 'fmtmsg' function.
* Adding Severity Classes       Add more severity classes.
* Example                       How to use 'fmtmsg' and 'addseverity'.
 Low-Level I/O
* Opening and Closing Files           How to open and close file
* I/O Primitives                      Reading and writing data.
* File Position Primitive             Setting a descriptor's file
* Descriptors and Streams             Converting descriptor to stream
                                          or vice-versa.
* Stream/Descriptor Precautions       Precautions needed if you use both
                                          descriptors and streams.
* Scatter-Gather                      Fast I/O to discontinuous buffers.
* Memory-mapped I/O                   Using files like memory.
* Waiting for I/O                     How to check for input or output
 					 on multiple file descriptors.
* Synchronizing I/O                   Making sure all I/O actions completed.
* Asynchronous I/O                    Perform I/O in parallel.
* Control Operations                  Various other operations on file
* Duplicating Descriptors             Fcntl commands for duplicating
                                          file descriptors.
* Descriptor Flags                    Fcntl commands for manipulating
                                          flags associated with file
* File Status Flags                   Fcntl commands for manipulating
                                          flags associated with open files.
* File Locks                          Fcntl commands for implementing
                                          file locking.
* Interrupt Input                     Getting an asynchronous signal when
                                          input arrives.
* IOCTLs                              Generic I/O Control operations.
 Stream/Descriptor Precautions
* Linked Channels        Dealing with channels sharing a file position.
* Independent Channels   Dealing with separately opened, unlinked channels.
* Cleaning Streams       Cleaning a stream makes it safe to use
                             another channel.
 Asynchronous I/O
* Asynchronous Reads/Writes    Asynchronous Read and Write Operations.
* Status of AIO Operations     Getting the Status of AIO Operations.
* Synchronizing AIO Operations Getting into a consistent state.
* Cancel AIO Operations        Cancellation of AIO Operations.
* Configuration of AIO         How to optimize the AIO implementation.
 File Status Flags
* Access Modes                Whether the descriptor can read or write.
* Open-time Flags             Details of 'open'.
* Operating Modes             Special modes to control I/O operations.
* Getting File Status Flags   Fetching and changing these flags.
 File System Interface
* Working Directory           This is used to resolve relative
 				 file names.
* Accessing Directories       Finding out what files a directory
* Working with Directory Trees Apply actions to all files or a selectable
                                  subset of a directory hierarchy.
* Hard Links                  Adding alternate names to a file.
* Symbolic Links              A file that "points to" a file name.
* Deleting Files              How to delete a file, and what that means.
* Renaming Files              Changing a file's name.
* Creating Directories        A system call just for creating a directory.
* File Attributes             Attributes of individual files.
* Making Special Files        How to create special files.
* Temporary Files             Naming and creating temporary files.
 Accessing Directories
* Directory Entries           Format of one directory entry.
* Opening a Directory         How to open a directory stream.
* Reading/Closing Directory   How to read directory entries from the stream.
* Simple Directory Lister     A very simple directory listing program.
* Random Access Directory     Rereading part of the directory
                                  already read with the same stream.
* Scanning Directory Content  Get entries for user selected subset of
                                  contents in given directory.
* Simple Directory Lister Mark II  Revised version of the program.
 File Attributes
* Attribute Meanings          The names of the file attributes,
                                  and what their values mean.
* Reading Attributes          How to read the attributes of a file.
* Testing File Type           Distinguishing ordinary files,
                                  directories, links...
* File Owner                  How ownership for new files is determined,
 			         and how to change it.
* Permission Bits             How information about a file's access
                                  mode is stored.
* Access Permission           How the system decides who can access a file.
* Setting Permissions         How permissions for new files are assigned,
 			         and how to change them.
* Testing File Access         How to find out if your process can
                                  access a file.
* File Times                  About the time attributes of a file.
* File Size                   Manually changing the size of a file.
* Storage Allocation          Allocate backing storage for files.
 Pipes and FIFOs
* Creating a Pipe             Making a pipe with the 'pipe' function.
* Pipe to a Subprocess        Using a pipe to communicate with a
 				 child process.
* FIFO Special Files          Making a FIFO special file.
* Pipe Atomicity              When pipe (or FIFO) I/O is atomic.
* Socket Concepts     Basic concepts you need to know about.
* Communication StylesStream communication, datagrams and other styles.
* Socket Addresses    How socket names ("addresses") work.
* Interface Naming    Identifying specific network interfaces.
* Local Namespace     Details about the local namespace.
* Internet Namespace  Details about the Internet namespace.
* Misc Namespaces     Other namespaces not documented fully here.
* Open/Close Sockets  Creating sockets and destroying them.
* Connections         Operations on sockets with connection state.
* Datagrams           Operations on datagram sockets.
* Inetd               Inetd is a daemon that starts servers on request.
 			   The most convenient way to write a server
 			   is to make it work with Inetd.
* Socket Options      Miscellaneous low-level socket options.
* Networks Database   Accessing the database of network names.
 Socket Addresses
* Address Formats             About 'struct sockaddr'.
* Setting Address             Binding an address to a socket.
* Reading Address             Reading the address of a socket.
 Local Namespace
* Concepts Local Namespace Concepts. What you need to understand.
* Details Local Namespace Details.   Address format, symbolic names, etc.
* Example Local Socket Example.      Example of creating a socket.
 Internet Namespace
* Internet Address Formats    How socket addresses are specified in the
                                  Internet namespace.
* Host Addresses              All about host addresses of Internet host.
* Ports                       Internet port numbers.
* Services Database           Ports may have symbolic names.
* Byte Order                  Different hosts may use different byte
                                  ordering conventions; you need to
                                  canonicalize host address and port number.
* Protocols Database          Referring to protocols by name.
* Inet Example                Putting it all together.
 Host Addresses
* Abstract Host Addresses     What a host number consists of.
* Data type Host Address Data Type.    Data type for a host number.
* Functions Host Address Functions.    Functions to operate on them.
* Names Host Names.            Translating host names to host numbers.
 Open/Close Sockets
* Creating a Socket           How to open a socket.
* Closing a Socket            How to close a socket.
* Socket Pairs                These are created like pipes.
* Connecting               What the client program must do.
* Listening                How a server program waits for requests.
* Accepting Connections    What the server does when it gets a request.
* Who is Connected         Getting the address of the
 				other side of a connection.
* Transferring Data        How to send and receive data.
* Byte Stream Example      An example program: a client for communicating
 			      over a byte stream socket in the Internet namespace.
* Server Example           A corresponding server program.
* Out-of-Band Data         This is an advanced feature.
 Transferring Data
* Sending Data                Sending data with 'send'.
* Receiving Data              Reading data with 'recv'.
* Socket Data Options         Using 'send' and 'recv'.
* Sending Datagrams    Sending packets on a datagram socket.
* Receiving Datagrams  Receiving packets on a datagram socket.
* Datagram Example     An example program: packets sent over a
                            datagram socket in the local namespace.
* Example Receiver     Another program, that receives those packets.
* Inetd Servers
* Configuring Inetd
 Socket Options
* Socket Option Functions     The basic functions for setting and getting
                                  socket options.
* Socket-Level Options        Details of the options at the socket level.
 Low-Level Terminal Interface
* Is It a Terminal            How to determine if a file is a terminal
 			         device, and what its name is.
* I/O Queues                  About flow control and typeahead.
* Canonical or Not            Two basic styles of input processing.
* Terminal Modes              How to examine and modify flags controlling
 			         details of terminal I/O: echoing,
                                  signals, editing.  Posix.
* BSD Terminal Modes          BSD compatible terminal mode setting
* Line Control                Sending break sequences, clearing
                                  terminal buffers ...
* Noncanon Example            How to read single characters without echo.
* Pseudo-Terminals            How to open a pseudo-terminal.
 Terminal Modes
* Mode Data Types             The data type 'struct termios' and
                                  related types.
* Mode Functions              Functions to read and set the terminal
* Setting Modes               The right way to set terminal attributes
* Input Modes                 Flags controlling low-level input handling.
* Output Modes                Flags controlling low-level output handling.
* Control Modes               Flags controlling serial port behavior.
* Local Modes                 Flags controlling high-level input handling.
* Line Speed                  How to read and set the terminal line speed.
* Special Characters          Characters that have special effects,
 			         and how to change them.
* Noncanonical Input          Controlling how long to wait for input.
 Special Characters
* Editing Characters          Special characters that terminate lines and
                                   delete text, and other editing functions.
* Signal Characters           Special characters that send or raise signals
                                   to or for certain classes of processes.
* Start/Stop Characters       Special characters that suspend or resume
                                   suspended output.
* Other Special               Other special characters for BSD systems:
 				  they can discard output, and print status.
* Allocation             Allocating a pseudo terminal.
* Pseudo-Terminal Pairs  How to open both sides of a
                             pseudo-terminal in a single operation.
* Overview of Syslog           Overview of a system's Syslog facility
* Submitting Syslog Messages   Functions to submit messages to Syslog
 Submitting Syslog Messages
* openlog                      Open connection to Syslog
* syslog; vsyslog              Submit message to Syslog
* closelog                     Close connection to Syslog
* setlogmask                   Cause certain messages to be ignored
* Syslog Example               Example of all of the above
* Mathematical Constants      Precise numeric values for often-used
* Trig Functions              Sine, cosine, tangent, and friends.
* Inverse Trig Functions      Arcsine, arccosine, etc.
* Exponents and Logarithms    Also pow and sqrt.
* Hyperbolic Functions        sinh, cosh, tanh, etc.
* Special Functions           Bessel, gamma, erf.
* Errors in Math Functions    Known Maximum Errors in Math Functions.
* Pseudo-Random Numbers       Functions for generating pseudo-random
* FP Function Optimizations   Fast code or small code.
 Pseudo-Random Numbers
* ISO Random                  'rand' and friends.
* BSD Random                  'random' and friends.
* SVID Random                 'drand48' and friends.
* Integers                    Basic integer types and concepts
* Integer Division            Integer division with guaranteed rounding.
* Floating Point Numbers      Basic concepts.  IEEE 754.
* Floating Point Classes      The five kinds of floating-point number.
* Floating Point Errors       When something goes wrong in a calculation.
* Rounding                    Controlling how results are rounded.
* Control Functions           Saving and restoring the FPU's state.
* Arithmetic Functions        Fundamental operations provided by the library.
* Complex Numbers             The types.  Writing complex constants.
* Operations on Complex       Projection, conjugation, decomposition.
* Parsing of Numbers          Converting strings to numbers.
* System V Number Conversion  An archaic way to convert numbers to strings.
 Floating Point Errors
* FP Exceptions               IEEE 754 math exceptions and how to detect them.
* Infinity and NaN            Special values returned by calculations.
* Status bit operations       Checking for exceptions after the fact.
* Math Error Reporting        How the math functions report errors.
 Arithmetic Functions
* Absolute Value              Absolute values of integers and floats.
* Normalization Functions     Extracting exponents and putting them back.
* Rounding Functions          Rounding floats to integers.
* Remainder Functions         Remainders on division, precisely defined.
* FP Bit Twiddling            Sign bit adjustment.  Adding epsilon.
* FP Comparison Functions     Comparisons without risk of exceptions.
* Misc FP Arithmetic          Max, min, positive difference, multiply-add.
 Parsing of Numbers
* Parsing of Integers         Functions for conversion of integer values.
* Parsing of Floats           Functions for conversion of floating-point
 Date and Time
* Time Basics                 Concepts and definitions.
* Elapsed Time                Data types to represent elapsed times
* Processor And CPU Time      Time a program has spent executing.
* Calendar Time               Manipulation of "real" dates and times.
* Setting an Alarm            Sending a signal after a specified time.
* Sleeping                    Waiting for a period of time.
 Processor And CPU Time
* CPU Time                    The 'clock' function.
* Processor Time              The 'times' function.
 Calendar Time
* Simple Calendar Time        Facilities for manipulating calendar time.
* High-Resolution Calendar    A time representation with greater precision.
* Broken-down Time            Facilities for manipulating local time.
* High Accuracy Clock         Maintaining a high accuracy system clock.
* Formatting Calendar Time    Converting times to strings.
* Parsing Date and Time       Convert textual time and date information back
                                  into broken-down time values.
* TZ Variable                 How users specify the time zone.
* Time Zone Functions         Functions to examine or specify the time zone.
* Time Functions Example      An example program showing use of some of
 				 the time functions.
 Parsing Date and Time
* Low-Level Time String Parsing  Interpret string according to given format.
* General Time String Parsing    User-friendly function to parse data and
                                     time strings.
 Resource Usage And Limitation
* Resource Usage              Measuring various resources used.
* Limits on Resources         Specifying limits on resource usage.
* Priority                    Reading or setting process run priority.
* Memory Resources            Querying memory available resources.
* Processor Resources         Learn about the processors available.
* Absolute Priority               The first tier of priority.  Posix
* Realtime Scheduling             Scheduling among the process nobility
* Basic Scheduling Functions      Get/set scheduling policy, priority
* Traditional Scheduling          Scheduling among the vulgar masses
* CPU Affinity                    Limiting execution to certain CPUs
 Traditional Scheduling
* Traditional Scheduling Intro
* Traditional Scheduling Functions
 Memory Resources
* Memory Subsystem           Overview about traditional Unix memory handling.
* Query Memory Parameters    How to get information about the memory
 Non-Local Exits
* Intro Non-Local Intro.        When and how to use these facilities.
* Details Non-Local Details.    Functions for non-local exits.
* Non-Local Exits and Signals  Portability issues.
* System V contexts            Complete context control a la System V.
 Signal Handling
* Concepts of Signals         Introduction to the signal facilities.
* Standard Signals            Particular kinds of signals with
                                  standard names and meanings.
* Signal Actions              Specifying what happens when a
                                  particular signal is delivered.
* Defining Handlers           How to write a signal handler function.
* Interrupted Primitives      Signal handlers affect use of 'open',
 				 'read', 'write' and other functions.
* Generating Signals          How to send a signal to a process.
* Blocking Signals            Making the system hold signals temporarily.
* Waiting for a Signal        Suspending your program until a signal
* Signal Stack                Using a Separate Signal Stack.
* BSD Signal Handling         Additional functions for backward
 			         compatibility with BSD.
 Concepts of Signals
* Kinds of Signals            Some examples of what can cause a signal.
* Signal Generation           Concepts of why and how signals occur.
* Delivery of Signal          Concepts of what a signal does to the
 Standard Signals
* Program Error Signals       Used to report serious program errors.
* Termination Signals         Used to interrupt and/or terminate the
* Alarm Signals               Used to indicate expiration of timers.
* Asynchronous I/O Signals    Used to indicate input is available.
* Job Control Signals         Signals used to support job control.
* Operation Error Signals     Used to report operational system errors.
* Miscellaneous Signals       Miscellaneous Signals.
* Signal Messages             Printing a message describing a signal.
 Signal Actions
* Basic Signal Handling       The simple 'signal' function.
* Advanced Signal Handling    The more powerful 'sigaction' function.
* Signal and Sigaction        How those two functions interact.
* Sigaction Function Example  An example of using the sigaction function.
* Flags for Sigaction         Specifying options for signal handling.
* Initial Signal Actions      How programs inherit signal actions.
 Defining Handlers
* Handler Returns             Handlers that return normally, and what
                                  this means.
* Termination in Handler      How handler functions terminate a program.
* Longjmp in Handler          Nonlocal transfer of control out of a
                                  signal handler.
* Signals in Handler          What happens when signals arrive while
                                  the handler is already occupied.
* Merged Signals              When a second signal arrives before the
 				 first is handled.
* Nonreentrancy               Do not call any functions unless you know they
                                  are reentrant with respect to signals.
* Atomic Data Access          A single handler can run in the middle of
                                  reading or writing a single object.
 Atomic Data Access
* Non-atomic Example          A program illustrating interrupted access.
* Types Atomic Types.          Data types that guarantee no interruption.
* Usage Atomic Usage.          Proving that interruption is harmless.
 Generating Signals
* Signaling Yourself          A process can send a signal to itself.
* Signaling Another Process   Send a signal to another process.
* Permission for kill         Permission for using 'kill'.
* Kill Example                Using 'kill' for Communication.
 Blocking Signals
* Why Block                           The purpose of blocking signals.
* Signal Sets                         How to specify which signals to
* Process Signal Mask                 Blocking delivery of signals to your
 				         process during normal execution.
* Testing for Delivery                Blocking to Test for Delivery of
                                          a Signal.
* Blocking for Handler                Blocking additional signals while a
 				         handler is being run.
* Checking for Pending Signals        Checking for Pending Signals
* Remembering a Signal                How you can get almost the same
                                          effect as blocking a signal, by
                                          handling it and setting a flag
                                          to be tested later.
 Waiting for a Signal
* Using Pause                 The simple way, using 'pause'.
* Pause Problems              Why the simple way is often not very good.
* Sigsuspend                  Reliably waiting for a specific signal.
 BSD Signal Handling
* BSD Handler                 BSD Function to Establish a Handler.
* Blocking in BSD             BSD Functions for Blocking Signals.
 Program Basics
* Program Arguments           Parsing your program's command-line arguments
* Environment Variables       Less direct parameters affecting your program
* Auxiliary Vector            Least direct parameters affecting your program
* System Calls                Requesting service from the system
* Program Termination         Telling the system you're done; return status
 Program Arguments
* Argument Syntax             By convention, options start with a hyphen.
* Parsing Program Arguments   Ways to parse program options and arguments.
 Parsing Program Arguments
* Getopt                      Parsing program options using 'getopt'.
* Argp                        Parsing program options using 'argp_parse'.
* Suboptions                  Some programs need more detailed options.
* Suboptions Example          This shows how it could be done for 'mount'.
 Environment Variables
* Environment Access          How to get and set the values of
 				 environment variables.
* Standard Environment        These environment variables have
                 		 standard interpretations.
 Program Termination
* Normal Termination          If a program calls 'exit', a
                                  process terminates normally.
* Exit Status                 The 'exit status' provides information
                                  about why the process terminated.
* Cleanups on Exit            A process can run its own cleanup
                                  functions upon normal termination.
* Aborting a Program          The 'abort' function causes
                                  abnormal program termination.
* Termination Internals       What happens when a process terminates.
* Running a Command           The easy way to run another program.
* Process Creation Concepts   An overview of the hard way to do it.
* Process Identification      How to get the process ID of a process.
* Creating a Process          How to fork a child process.
* Executing a File            How to make a process execute another program.
* Process Completion          How to tell when a child process has completed.
* Process Completion Status   How to interpret the status value
                                  returned from a child process.
* BSD Wait Functions          More functions, for backward compatibility.
* Process Creation Example    A complete example program.
 Inter-Process Communication
* Semaphores  Support for creating and managing semaphores
 Job Control
* Concepts of Job Control     Jobs can be controlled by a shell.
* Job Control is Optional     Not all POSIX systems support job control.
* Controlling Terminal        How a process gets its controlling terminal.
* Access to the Terminal      How processes share the controlling terminal.
* Orphaned Process Groups     Jobs left after the user logs out.
* Implementing a Shell        What a shell must do to implement job control.
* Functions for Job Control   Functions to control process groups.
 Implementing a Shell
* Data Structures             Introduction to the sample shell.
* Initializing the Shell      What the shell must do to take
 				 responsibility for job control.
* Launching Jobs              Creating jobs to execute commands.
* Foreground and Background   Putting a job in foreground of background.
* Stopped and Terminated Jobs  Reporting job status.
* Continuing Stopped Jobs     How to continue a stopped job in
 				 the foreground or background.
* Missing Pieces              Other parts of the shell.
 Functions for Job Control
* Identifying the Terminal    Determining the controlling terminal's name.
* Process Group Functions     Functions for manipulating process groups.
* Terminal Access Functions   Functions for controlling terminal access.
 Name Service Switch
* NSS Basics                  What is this NSS good for.
* NSS Configuration File      Configuring NSS.
* NSS Module Internals        How does it work internally.
* Extending NSS               What to do to add services or databases.
 NSS Configuration File
* Services in the NSS configuration  Service names in the NSS configuration.
* Actions in the NSS configuration  React appropriately to the lookup result.
* Notes on NSS Configuration File  Things to take care about while
                                      configuring NSS.
 NSS Module Internals
* NSS Module Names            Construction of the interface function of
                                 the NSS modules.
* NSS Modules Interface       Programming interface in the NSS module
 Extending NSS
* Adding another Service to NSS  What is to do to add a new service.
* NSS Module Function Internals  Guidelines for writing new NSS
                                         service functions.
 Users and Groups
* User and Group IDs          Each user has a unique numeric ID;
 				 likewise for groups.
* Process Persona             The user IDs and group IDs of a process.
* Why Change Persona          Why a program might need to change
 				 its user and/or group IDs.
* How Change Persona          Changing the user and group IDs.
* Reading Persona             How to examine the user and group IDs.
* Setting User ID             Functions for setting the user ID.
* Setting Groups              Functions for setting the group IDs.
* Enable/Disable Setuid       Turning setuid access on and off.
* Setuid Program Example      The pertinent parts of one sample program.
* Tips for Setuid             How to avoid granting unlimited access.
* Who Logged In               Getting the name of the user who logged in,
 				 or of the real user ID of the current process.
* User Accounting Database    Keeping information about users and various
                                  actions in databases.
* User Database               Functions and data structures for
                         	 accessing the user database.
* Group Database              Functions and data structures for
                         	 accessing the group database.
* Database Example            Example program showing the use of database
 				 inquiry functions.
* Netgroup Database           Functions for accessing the netgroup database.
 User Accounting Database
* Manipulating the Database   Scanning and modifying the user
                                  accounting database.
* XPG Functions               A standardized way for doing the same thing.
* Logging In and Out          Functions from BSD that modify the user
                                  accounting database.
 User Database
* User Data Structure         What each user record contains.
* Lookup User                 How to look for a particular user.
* Scanning All Users          Scanning the list of all users, one by one.
* Writing a User Entry        How a program can rewrite a user's record.
 Group Database
* Group Data Structure        What each group record contains.
* Lookup Group                How to look for a particular group.
* Scanning All Groups         Scanning the list of all groups.
 Netgroup Database
* Netgroup Data                  Data in the Netgroup database and where
                                    it comes from.
* Lookup Netgroup                How to look for a particular netgroup.
* Netgroup Membership            How to test for netgroup membership.
 System Management
* Host Identification         Determining the name of the machine.
* Platform Type               Determining operating system and basic
                                   machine type
* Filesystem Handling         Controlling/querying mounts
* System Parameters           Getting and setting various system parameters
 Filesystem Handling
* Mount Information           What is or could be mounted?
* Mount-Unmount-Remount       Controlling what is mounted and how
 Mount Information
* fstab                       The 'fstab' file
* mtab                        The 'mtab' file
* Other Mount Information     Other (non-libc) sources of mount information
 System Configuration
* General Limits           Constants and functions that describe
 				various process-related limits that have
 				one uniform value for any given machine.
* System Options           Optional POSIX features.
* Version Supported        Version numbers of POSIX.1 and POSIX.2.
* Sysconf                  Getting specific configuration values
                                 of general limits and system options.
* Minimums                 Minimum values for general limits.
* Limits for Files         Size limitations that pertain to individual files.
                                 These can vary between file systems
                                 or even from file to file.
* Options for Files        Optional features that some files may support.
* File Minimums            Minimum values for file limits.
* Pathconf                 Getting the limit values for a particular file.
* Utility Limits           Capacity limits of some POSIX.2 utility programs.
* Utility Minimums         Minimum allowable values of those limits.
* String Parameters        Getting the default search path.
* Sysconf Definition        Detailed specifications of 'sysconf'.
* Constants for Sysconf     The list of parameters 'sysconf' can read.
* Examples of Sysconf       How to use 'sysconf' and the parameter
 				 macros properly together.
 Cryptographic Functions
* Legal Problems              This software can get you locked up, or worse.
* getpass                     Prompting the user for a password.
* crypt                       A one-way function for passwords.
* DES Encryption              Routines for DES encryption.
 Debugging Support
* Backtraces                Obtaining and printing a back trace of the
                                current stack.
 POSIX Threads
* Thread-specific Data          Support for creating and
 				  managing thread-specific data
* Non-POSIX Extensions          Additional functions to extend
 				  POSIX Thread functionality
 Non-POSIX Extensions
* Default Thread Attributes             Setting default attributes for
 					  threads in a process.
 Internal Probes
* Memory Allocation Probes  Probes in the memory allocation subsystem
 Language Features
* Consistency Checking        Using 'assert' to abort if
 				 something "impossible" happens.
* Variadic Functions          Defining functions with varying numbers
                                  of args.
* Null Pointer Constant       The macro 'NULL'.
* Important Data Types        Data types for object sizes.
* Data Type Measurements      Parameters of data type representations.
 Variadic Functions
* Why Variadic                Reasons for making functions take
                                  variable arguments.
* How Variadic                How to define and call variadic functions.
* Variadic Example            A complete example.
 How Variadic
* Variadic Prototypes  How to make a prototype for a function
 			  with variable arguments.
* Receiving Arguments  Steps you must follow to access the
 			  optional argument values.
* How Many Arguments   How to decide whether there are more arguments.
* Calling Variadics    Things you need to know about calling
 			  variable arguments functions.
* Argument Macros      Detailed specification of the macros
         		  for accessing variable arguments.
 Data Type Measurements
* Width of Type           How many bits does an integer type hold?
* Range of Type           What are the largest and smallest values
 			     that an integer type can hold?
* Floating Type Macros    Parameters that measure the floating point types.
* Structure Measurement   Getting measurements on structure types.
 Floating Type Macros
* Floating Point Concepts     Definitions of terminology.
* Floating Point Parameters   Details of specific macros.
* IEEE Floating Point         The measurements for one common
* Configuring and compiling   How to compile and test GNU libc.
* Running make install        How to install it once you've got it
* Tools for Compilation       You'll need these first.
* Linux                       Specific advice for GNU/Linux systems.
* Reporting Bugs              So they'll get fixed.
* Source Layout         How to add new functions or header files
                              to the GNU C Library.
* Porting               How to port the GNU C Library to
                              a new machine or operating system.
 Source Layout
* Platform Adding Platform-specific.             Adding platform-specific
* Hierarchy Conventions       The layout of the 'sysdeps' hierarchy.
* Porting to Unix             Porting the library to an average
                                    Unix-like system.
* PowerPC           Facilities Specific to the PowerPC Architecture
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