The Linux Programming Interface

Praise for The Linux Programming Interface; Dedication; Preface;; Chapter 1: History and Standards; 1.1 A Brief History of UNIX and C; 1.2 A Brief History of Linux; 1.3 Standardization; 1.4 Summary; Chapter 2: Fundamental Concepts; 2.1 The Core Operating System: The Kernel; 2.2 The Shell; 2.3 Users and Groups; 2.4 Single Directory Hierarchy, Directories, Links, and Files; 2.5 File I/O Model; 2.6 Programs; 2.7 Processes; 2.8 Memory Mappings; 2.9 Static and Shared Libraries; 2.10 Interprocess Communication and Synchronization; 2.11 Signals; 2.12 Threads; 2.13 Process Groups and Shell Job Control; 2.14 Sessions, Controlling Terminals, and Controlling Processes; 2.15 Pseudoterminals; 2.16 Date and Time; 2.17 Client-Server Architecture; 2.18 Realtime; 2.19 The /proc File System; 2.20 Summary; Chapter 3: System Programming Concepts; 3.1 System Calls; 3.2 Library Functions; 3.3 The Standard C Library; The GNU C Library (glibc); 3.4 Handling Errors from System Calls and Library Functions; 3.5 Notes on the Example Programs in This Book; 3.6 Portability Issues; 3.7 Summary; 3.8 Exercise; Chapter 4: File I/O: The Universal I/O Model; 4.1 Overview; 4.2 Universality of I/O; 4.3 Opening a File: open(); 4.4 Reading from a File: read(); 4.5 Writing to a File: write(); 4.6 Closing a File: close(); 4.7 Changing the File Offset: lseek(); 4.8 Operations Outside the Universal I/O Model: ioctl(); 4.9 Summary; 4.10 Exercises; Chapter 5: File I/O: Further Details; 5.1 Atomicity and Race Conditions; 5.2 File Control Operations: fcntl(); 5.3 Open File Status Flags; 5.4 Relationship Between File Descriptors and Open Files; 5.5 Duplicating File Descriptors; 5.6 File I/O at a Specified Offset: pread() and pwrite(); 5.7 Scatter-Gather I/O: readv() and writev(); 5.8 Truncating a File: truncate() and ftruncate(); 5.9 Nonblocking I/O; 5.10 I/O on Large Files; 5.11 The /dev/fd Directory; 5.12 Creating Temporary Files; 5.13 Summary; 5.14 Exercises; Chapter 6: Processes; 6.1 Processes and Programs; 6.2 Process ID and Parent Process ID; 6.3 Memory Layout of a Process; 6.4 Virtual Memory Management; 6.5 The Stack and Stack Frames; 6.6 Command-Line Arguments (argc, argv); 6.7 Environment List; 6.8 Performing a Nonlocal Goto: setjmp() and long jmp(); 6.9 Summary; 6.10 Exercises; Chapter 7: Memory Allocation; 7.1 Allocating Memory on the Heap; 7.2 Allocating Memory on the Stack: alloca(); 7.3 Summary; 7.4 Exercises; Chapter 8: Users and Groups; 8.1 The Password File: /etc/passwd; 8.2 The Shadow Password File: /etc/shadow; 8.3 The Group File: /etc/group; 8.4 Retrieving User and Group Information; 8.5 Password Encryption and User Authentication; 8.6 Summary; 8.7 Exercises; Chapter 9: Process Credentials; 9.1 Real User ID and Real Group ID; 9.2 Effective User ID and Effective Group ID; 9.3 Set-User-ID and Set-Group-ID Programs; 9.4 Saved Set-User-ID and Saved Set-Group-ID; 9.5 File-System User ID and File-System Group ID; 9.6 Supplementary Group IDs; 9.7 Retrieving and Modifying Process Credentials; 9.8 Summary; 9.9 Exercises; Chapter 10: Time; 10.1 Calendar Time; 10.2 Time-Conversion Functions; 10.3 Timezones; 10.4 Locales; 10.5 Updating the System Clock; 10.6 The Software Clock (Jiffies); 10.7 Process Time; 10.8 Summary; 10.9 Exercise; Chapter 11: System Limits and Options; 11.1 System Limits; 11.2 Retrieving System Limits (and Options) at Run Time; 11.3 Retrieving File-Related Limits (and Options) at Run Time; 11.4 Indeterminate Limits; 11.5 System Options; 11.6 Summary; 11.7 Exercises; Chapter 12: System and Process Information; 12.1 The /proc File System; 12.2 System Identification: uname(); 12.3 Summary; 12.4 Exercises; Chapter 13: File I/O Buffering; 13.1 Kernel Buffering of File I/O: The Buffer Cache; 13.2 Buffering in the stdio Library; 13.3 Controlling Kernel Buffering of File I/O; 13.4 Summary of I/O Buffering; 13.5 Advising the Kernel About I/O Patterns; 13.6 Bypassing the Buffer Cache: Direct I/O; 13.7 Mixing Library Functions and System Calls for File I/O; 13.8 Summary; 13.9 Exercises; Chapter 14: File Systems; 14.1 Device Special Files (Devices); 14.2 Disks and Partitions; 14.3 File Systems; 14.4 I-nodes; 14.5 The Virtual File System (VFS); 14.6 Journaling File Systems; 14.7 Single Directory Hierarchy and Mount Points; 14.8 Mounting and Unmounting File Systems; 14.9 Advanced Mount Features; 14.10 A Virtual Memory File System: tmpfs; 14.11 Obtaining Information About a File System: statvfs(); 14.12 Summary; 14.13 Exercise; Chapter 15: File Attributes; 15.1 Retrieving File Information: stat(); 15.2 File Timestamps; 15.3 File Ownership; 15.4 File Permissions; 15.5 I-node Flags (ext2 Extended File Attributes); 15.6 Summary; 15.7 Exercises; Chapter 16: Extended Attributes;;;;;; 16.1 Overview; 16.2 Extended Attribute Implementation Details; 16.3 System Calls for Manipulating Extended Attributes; 16.4 Summary; 16.5 Exercise; Chapter 17: Access Control Lists; 17.1 Overview; 17.2 ACL Permission-Checking Algorithm; 17.3 Long and Short Text Forms for ACLs; 17.4 The ACL_MASK Entry and the ACL Group Class; 17.5 The getfacl and setfacl Commands; 17.6 Default ACLs and File Creation; 17.7 ACL Implementation Limits; 17.8 The ACL API; 17.9 Summary; 17.10 Exercise; Chapter 18: Directories and Links; 18.1 Directories and (Hard) Links; 18.2 Symbolic (Soft) Links; 18.3 Creating and Removing (Hard) Links: link() and unlink(); 18.4 Changing the Name of a File: rename(); 18.5 Working with Symbolic Links: symlink() and readlink(); 18.6 Creating and Removing Directories: mkdir() and rmdir(); 18.7 Removing a File or Directory: remove(); 18.8 Reading Directories: opendir() and readdir(); 18.9 File Tree Walking: nftw(); 18.10 The Current Working Directory of a Process; 18.11 Operating Relative to a Directory File Descriptor; 18.12 Changing the Root Directory of a Process: chroot(); 18.13 Resolving a Pathname: realpath(); 18.14 Parsing Pathname Strings: dirname() and basename(); 18.15 Summary; 18.16 Exercises; Chapter 19: Monitoring File Events; 19.1 Overview; 19.2 The inotify API; 19.3 inotify Events; 19.4 Reading inotify Events; 19.5 Queue Limits and /proc Files; 19.6 An Older System for Monitoring File Events: dnotify; 19.7 Summary; 19.8 Exercise; Chapter 20: Signals: Fundamental Concepts; 20.1 Concepts and Overview; 20.2 Signal Types and Default Actions; 20.3 Changing Signal Dispositions: signal(); 20.4 Introduction to Signal Handlers; 20.5 Sending Signals: kill(); 20.6 Checking for the Existence of a Process; 20.7 Other Ways of Sending Signals: raise() and killpg(); 20.8 Displaying Signal Descriptions; 20.9 Signal Sets; 20.10 The Signal Mask (Blocking Signal Delivery); 20.11 Pending Signals; 20.12 Signals Are Not Queued; 20.13 Changing Signal Dispositions: sigaction(); 20.14 Waiting for a Signal: pause(); 20.15 Summary; 20.16 Exercises; Chapter 21: Signals: Signal Handlers; 21.1 Designing Signal Handlers; 21.2 Other Methods of Terminating a Signal Handler; 21.3 Handling a Signal on an Alternate Stack: sigaltstack(); 21.4 The SA_SIGINFO Flag; 21.5 Interruption and Restarting of System Calls; 21.6 Summary; 21.7 Exercise; Chapter 22: Signals: Advanced Features; 22.1 Core Dump Files; 22.2 Special Cases for Delivery, Disposition, and Handling; 22.3 Interruptible and Uninterruptible Process Sleep States; 22.4 Hardware-Generated Signals; 22.5 Synchronous and Asynchronous Signal Generation; 22.6 Timing and Order of Signal Delivery; 22.7 Implementation and Portability of signal(); 22.8 Realtime Signals; 22.9 Waiting for a Signal Using a Mask: sigsuspend(); 22.10 Synchronously Waiting for a Signal; 22.11 Fetching Signals via a File Descriptor; 22.12 Interprocess Communication with Signals; 22.13 Earlier Signal APIs (System V and BSD); 22.14 Summary; 22.15 Exercises; Chapter 23: Timers and Sleeping; 23.1 Interval Timers; 23.2 Scheduling and Accuracy of Timers; 23.3 Setting Timeouts on Blocking Operations; 23.4 Suspending Execution for a Fixed Interval (Sleeping); 23.5 POSIX Clocks; 23.6 POSIX Interval Timers; 23.7 Timers That Notify via File Descriptors: The timerfd API; 23.8 Summary; 23.9 Exercises; Chapter 24: Process Creation; 24.1 Overview of fork(), exit(), wait(), and execve(); 24.2 Creating a New Process: fork(); 24.3 The vfork() System Call; 24.4 Race Conditions After fork(); 24.5 Avoiding Race Conditions by Synchronizing with Signals; 24.6 Summary; 24.7 Exercises; Chapter 25: Process Termination; 25.1 Terminating a Process: _exit() and exit(); 25.2 Details of Process Termination; 25.3 Exit Handlers; 25.4 Interactions Between fork(), stdio Buffers, and _exit(); 25.5 Summary; 25.6 Exercise; Chapter 26: Monitoring Child Processes; 26.1 Waiting on a Child Process; 26.2 Orphans and Zombies; 26.3 The SIGCHLD Signal; 26.4 Summary; 26.5 Exercises; Chapter 27: Program Execution; 27.1 Executing a New Program: execve(); 27.2 The exec() Library Functions; 27.3 Interpreter Scripts; 27.4 File Descriptors and exec(); 27.5 Signals and exec(); 27.6 Executing a Shell Command: system(); 27.7 Implementing system(); 27.8 Summary; 27.9 Exercises; Chapter 28: Process Creation and Program Execution in More Detail; 28.1 Process Accounting; 28.2 The clone() System Call; 28.3 Speed of Process Creation; 28.4 Effect of exec() and fork() on Process Attributes; 28.5 Summary; 28.6 Exercise; Chapter 29: Threads: Introduction; 29.1 Overview; 29.2 Background Details of the Pthreads API; 29.3 Thread Creation; 29.4 Thread Termination; 29.5 Thread IDs; 29.6 Joining with a Terminated Thread; 29.7 Detaching a Thread; 29.8 Thread Attributes; 29.9 Threads Versus Processes; 29.10 Summary; 29.11 Exercises; Chapter 30: Threads: Thread Synchronization; 30.1 Protecting Accesses to Shared Variables: Mutexes; 30.2 Signaling Changes of State: Condition Variables; 30.3 Summary; 30.4 Exercises; Chapter 31: Threads: Thread Safety and Per-Thread Storage; 31.1 Thread Safety (and Reentrancy Revisited); 31.2 One-Time Initialization; 31.3 Thread-Specific Data; 31.4 Thread-Local Storage; 31.5 Summary; 31.6 Exercises; Chapter 32: Threads: Thread Cancellation; 32.1 Canceling a Thread; 32.2 Cancellation State and Type; 32.3 Cancellation Points; 32.4 Testing for Thread Cancellation; 32.5 Cleanup Handlers; 32.6 Asynchronous Cancelability; 32.7 Summary; Chapter 33: Threads: Further Details; 33.1 Thread Stacks; 33.2 Threads and Signals; 33.3 Threads and Process Control; 33.4 Thread Implementation Models; 33.5 Linux Implementations of POSIX Threads; 33.6 Advanced Features of the Pthreads API; 33.7 Summary; 33.8 Exercises; Chapter 34: Process Groups, Sessions, and Job Control; 34.1 Overview; 34.2 Process Groups; 34.3 Sessions; 34.4 Controlling Terminals and Controlling Processes; 34.5 Foreground and Background Process Groups; 34.6 The SIGHUP Signal; 34.7 Job Control; 34.8 Summary; 34.9 Exercises; Chapter 35: Process Priorities and Scheduling; 35.1 Process Priorities (Nice Values); 35.2 Overview of Realtime Process Scheduling; 35.3 Realtime Process Scheduling API; 35.4 CPU Affinity; 35.5 Summary; 35.6 Exercises; Chapter 36: Process Resources; 36.1 Process Resource Usage; 36.2 Process Resource Limits; 36.3 Details of Specific Resource Limits; 36.4 Summary; 36.5 Exercises; Chapter 37: Daemons; 37.1 Overview; 37.2 Creating a Daemon; 37.3 Guidelines for Writing Daemons; 37.4 Using SIGHUP to Reinitialize a Daemon; 37.5 Logging Messages and Errors Using syslog; 37.6 Summary; 37.7 Exercise; Chapter 38: Writing Secure Privileged Programs; 38.1 Is a Set-User-ID or Set-Group-ID Program Required?; 38.2 Operate with Least Privilege; 38.3 Be Careful When Executing a Program; 38.4 Avoid Exposing Sensitive Information; 38.5 Confine the Process; 38.6 Beware of Signals and Race Conditions; 38.7 Pitfalls When Performing File Operations and File I/O; 38.8 Don't Trust Inputs or the Environment; 38.9 Beware of Buffer Overruns; 38.10 Beware of Denial-of-Service Attacks; 38.11 Check Return Statuses and Fail Safely; 38.12 Summary; 38.13 Exercises; Chapter 39: Capabilities; 39.1 Rationale for Capabilities; 39.2 The Linux Capabilities; 39.3 Process and File Capabilities; 39.4 The Modern Capabilities Implementation; 39.5 Transformation of Process Capabilities During exec(); 39.6 Effect on Process Capabilities of Changing User IDs; 39.7 Changing Process Capabilities Programmatically; 39.8 Creating Capabilities-Only Environments; 39.9 Discovering the Capabilities Required by a Program; 39.10 Older Kernels and Systems Without File Capabilities; 39.11 Summary; 39.12 Exercise; Chapter 40: Login Accounting; 40.1 Overview of the utmp and wtmp Files; 40.2 The utmpx API; 40.3 The utmpx Structure; 40.4 Retrieving Information from the utmp and wtmp Files; 40.5 Retrieving the Login Name: getlogin(); 40.6 Updating the utmp and wtmp Files for a Login Session; 40.7 The lastlog File; 40.8 Summary; 40.9 Exercises; Chapter 41: Fundamentals of Shared Libraries; 41.1 Object Libraries; 41.2 Static Libraries; 41.3 Overview of Shared Libraries; 41.4 Creating and Using Shared Libraries--A First Pass; 41.5 Useful Tools for Working with Shared Libraries; 41.6 Shared Library Versions and Naming Conventions; 41.7 Installing Shared Libraries; 41.8 Compatible Versus Incompatible Libraries; 41.9 Upgrading Shared Libraries; 41.10 Specifying Library Search Directories in an Object File; 41.11 Finding Shared Libraries at Run Time; 41.12 Run-Time Symbol Resolution; 41.13 Using a Static Library Instead of a Shared Library; 41.14 Summary; 41.15 Exercise; Chapter 42: Advanced Features of Shared Libraries; 42.1 Dynamically Loaded Libraries; 42.2 Controlling Symbol Visibility; 42.3 Linker Version Scripts; 42.4 Initialization and Finalization Functions; 42.5 Preloading Shared Libraries; 42.6 Monitoring the Dynamic Linker: LD_DEBUG; 42.7 Summary; 42.8 Exercises; Chapter 43: Interprocess Communication Overview; 43.1 A Taxonomy of IPC Facilities; 43.2 Communication Facilities; 43.3 Synchronization Facilities; 43.4 Comparing IPC Facilities; 43.5 Summary; 43.6 Exercises; Chapter 44: Pipes and FIFOs; 44.1 Overview; 44.2 Creating and Using Pipes; 44.3 Pipes as a Method of Process Synchronization; 44.4 Using Pipes to Connect Filters; 44.5 Talking to a Shell Command via a Pipe: popen(); 44.6 Pipes and stdio Buffering; 44.7 FIFOs; 44.8 A Client-Server Application Using FIFOs; 44.9 Nonblocking I/O; 44.10 Semantics of read() and write() on Pipes and FIFOs; 44.11 Summary; 44.12 Exercises; Chapter 45: Introduction to System V IPC; 45.1 API Overview; 45.2 IPC Keys; 45.3 Associated Data Structure and Object Permissions; 45.4 IPC Identifiers and Client-Server Applications; 45.5 Algorithm Employed by System V IPC get Calls; 45.6 The ipcs and ipcrm Commands; 45.7 Obtaining a List of All IPC Objects; 45.8 IPC Limits; 45.9 Summary; 45.10 Exercises; Chapter 46: System V Message Queues; 46.1 Creating or Opening a Message Queue; 46.2 Exchanging Messages; 46.3 Message Queue Control Operations; 46.4 Message Queue Associated Data Structure; 46.5 Message Queue Limits; 46.6 Displaying All Message Queues on the System; 46.7 Client-Server Programming with Message Queues; 46.8 A File-Server Application Using Message Queues; 46.9 Disadvantages of System V Message Queues; 46.10 Summary; 46.11 Exercises; Chapter 47: System V Semaphores; 47.1 Overview; 47.2 Creating or Opening a Semaphore Set; 47.3 Semaphore Control Operations; 47.4 Semaphore Associated Data Structure; 47.5 Semaphore Initialization; 47.6 Semaphore Operations; 47.7 Handling of Multiple Blocked Semaphore Operations; 47.8 Semaphore Undo Values; 47.9 Implementing a Binary Semaphores Protocol; 47.10 Semaphore Limits; 47.11 Disadvantages of System V Semaphores; 47.12 Summary; 47.13 Exercises; Chapter 48: System V Shared Memory; 48.1 Overview; 48.2 Creating or Opening a Shared Memory Segment; 48.3 Using Shared Memory; 48.4 Example: Transferring Data via Shared Memory; 48.5 Location of Shared Memory in Virtual Memory; 48.6 Storing Pointers in Shared Memory; 48.7 Shared Memory Control Operations; 48.8 Shared Memory Associated Data Structure; 48.9 Shared Memory Limits; 48.10 Summary; 48.11 Exercises; Chapter 49: Memory Mappings; 49.1 Overview; 49.2 Creating a Mapping: mmap(); 49.3 Unmapping a Mapped Region: munmap(); 49.4 File Mappings; 49.5 Synchronizing a Mapped Region: msync(); 49.6 Additional mmap() Flags; 49.7 Anonymous Mappings; 49.8 Remapping a Mapped Region: mremap(); 49.9 MAP_NORESERVE and Swap Space Overcommitting; 49.10 The MAP_FIXED Flag; 49.11 Nonlinear Mappings: remap_file_pages(); 49.12 Summary; 49.13 Exercises; Chapter 50: Virtual Memory Operations; 50.1 Changing Memory Protection: mprotect(); 50.2 Memory Locking: mlock() and mlockall(); 50.3 Determining Memory Residence: mincore(); 50.4 Advising Future Memory Usage Patterns: madvise(); 50.5 Summary; 50.6 Exercises; Chapter 51: Introduction to POSIX IPC; 51.1 API Overview; 51.2 Comparison of System V IPC and POSIX IPC; 51.3 Summary; Chapter 52: POSIX Message Queues; 52.1 Overview; 52.2 Opening, Closing, and Unlinking a Message Queue; 52.3 Relationship Between Descriptors and Message Queues; 52.4 Message Queue Attributes; 52.5 Exchanging Messages; 52.6 Message Notification; 52.7 Linux-Specific Features; 52.8 Message Queue Limits; 52.9 Comparison of POSIX and System V Message Queues; 52.10 Summary; 52.11 Exercises; Chapter 53: POSIX Semaphores; 53.1 Overview; 53.2 Named Semaphores; 53.3 Semaphore Operations; 53.4 Unnamed Semaphores; 53.5 Comparisons with Other Synchronization Techniques; 53.6 Semaphore Limits; 53.7 Summary; 53.8 Exercises; Chapter 54: POSIX Shared Memory; 54.1 Overview; 54.2 Creating Shared Memory Objects; 54.3 Using Shared Memory Objects; 54.4 Removing Shared Memory Objects; 54.5 Comparisons Between Shared Memory APIs; 54.6 Summary; 54.7 Exercise; Chapter 55: File Locking; 55.1 Overview; 55.2 File Locking with flock(); 55.3 Record Locking with fcntl(); 55.4 Mandatory Locking; 55.5 The /proc/locks File; 55.6 Running Just One Instance of a Program; 55.7 Older Locking Techniques; 55.8 Summary; 55.9 Exercises; Chapter 56: Sockets: Introduction; 56.1 Overview; 56.2 Creating a Socket: socket(); 56.3 Binding a Socket to an Address: bind(); 56.4 Generic Socket Address Structures: struct sockaddr; 56.5 Stream Sockets; 56.6 Datagram Sockets; 56.7 Summary; Chapter 57: Sockets: UNIX Domain; 57.1 UNIX Domain Socket Addresses: struct sockaddr_un; 57.2 Stream Sockets in the UNIX Domain; 57.3 Datagram Sockets in the UNIX Domain; 57.4 UNIX Domain Socket Permissions; 57.5 Creating a Connected Socket Pair: socketpair(); 57.6 The Linux Abstract Socket Namespace; 57.7 Summary; 57.8 Exercises; Chapter 58: Sockets: Fundamentals of TCP/IP Networks; 58.1 Internets; 58.2 Networking Protocols and Layers; 58.3 The Data-Link Layer; 58.4 The Network Layer: IP; 58.5 IP Addresses; 58.6 The Transport Layer; 58.7 Requests for Comments (RFCs); 58.8 Summary; Chapter 59: Sockets: Internet Domains; 59.1 Internet Domain Sockets; 59.2 Network Byte Order; 59.3 Data Representation; 59.4 Internet Socket Addresses; 59.5 Overview of Host and Service Conversion Functions; 59.6 The inet_pton() and inet_ntop() Functions; 59.7 Client-Server Example (Datagram Sockets); 59.8 Domain Name System (DNS); 59.9 The /etc/services File; 59.10 Protocol-Independent Host and Service Conversion; 59.11 Client-Server Example (Stream Sockets); 59.12 An Internet Domain Sockets Library; 59.13 Obsolete APIs for Host and Service Conversions; 59.14 UNIX Versus Internet Domain Sockets; 59.15 Further Information; 59.16 Summary; 59.17 Exercises; Chapter 60: Sockets: Server Design; 60.1 Iterative and Concurrent Servers; 60.2 An Iterative UDP echo Server; 60.3 A Concurrent TCP echo Server; 60.4 Other Concurrent Server Designs; 60.5 The inetd (Internet Superserver) Daemon; 60.6 Summary; 60.7 Exercises; Chapter 61: Sockets: Advanced Topics; 61.1 Partial Reads and Writes on Stream Sockets; 61.2 The shutdown() System Call; 61.3 Socket-Specific I/O System Calls: recv() and send(); 61.4 The sendfile() System Call; 61.5 Retrieving Socket Addresses; 61.6 A Closer Look at TCP; 61.7 Monitoring Sockets: netstat; 61.8 Using tcpdump to Monitor TCP Traffic; 61.9 Socket Options; 61.10 The SO_REUSEADDR Socket Option; 61.11 Inheritance of Flags and Options Across accept(); 61.12 TCP Versus UDP; 61.13 Advanced Features; 61.14 Summary; 61.15 Exercises; Chapter 62: Terminals; 62.1 Overview; 62.2 Retrieving and Modifying Terminal Attributes; 62.3 The stty Command; 62.4 Terminal Special Characters; 62.5 Terminal Flags; 62.6 Terminal I/O Modes; 62.7 Terminal Line Speed (Bit Rate); 62.8 Terminal Line Control; 62.9 Terminal Window Size; 62.10 Terminal Identification; 62.11 Summary; 62.12 Exercises; Chapter 63: Alternative I/O Models; 63.1 Overview; 63.2 I/O Multiplexing; 63.3 Signal-Driven I/O; 63.4 The epoll API; 63.5 Waiting on Signals and File Descriptors; 63.6 Summary; 63.7 Exercises; Chapter 64: Pseudoterminals; 64.1 Overview; 64.2 UNIX 98 Pseudoterminals; 64.3 Opening a Master: ptyMasterOpen(); 64.4 Connecting Processes with a Pseudoterminal: ptyFork(); 64.5 Pseudoterminal I/O; 64.6 Implementing script(1); 64.7 Terminal Attributes and Window Size; 64.8 BSD Pseudoterminals; 64.9 Summary; 64.10 Exercises; Tracing System Calls; Parsing Command-Line Options; Example program; GNU-specific behavior; GNU extensions; Casting the NULL Pointer; Kernel Configuration; Further Sources of Information; Manual pages; GNU info documents; The GNU C library (glibc) manual; Books; Source code of existing applications; The Linux Documentation Project; The GNU project; Newsgroups; Linux kernel mailing list; Web sites; The kernel source code; Solutions to Selected Exercises;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; Bibliography; Updates; Colophon;