header files Overview header files A header file is a file of C code that contains definitions, dec- larations, and structures commonly used in a given situation. By tradition, a header file always has the suffix ``.h''. Header files are invoked within a C program by the command #include, which is read by cpp, the C preprocessor; for this reason, they are also called ``include files''. Header files are one of the most useful tools available to a C programmer. They allow you to put into one place all of the in- formation that the different modules of your program share. Proper use of header files will make your programs easier to maintain and to port to other environments. COHERENT includes the following header files: access.h Check accessibility acct.h Format for process-accounting file action.h Describe parsing action and goto tables sys/alloc.h Define the allocator ar.h Format for archive files ascii.h Define non-printable ASCII characters assert.h Define assert() sys/buf.h Buffer header canon.h Portable layout of binary data sys/chars.h Character definitions sys/con.h Configure device drivers sys/const.h Declare machine-dependent constants ctype.h Header file for data tests curses.h Declare/define curses routines sys/deftty.h Default tty settings sys/dir.h Directory format dirent.h Define constant dirent dumptape.h Define data structures for dump tapes ebcdic.h Define constants for non-printable EBCDIC characters errno.h Error numbers used by errno() sys/fblk.h Define disk-free block sys/fcntl.h Manifest constants for file-handling functions" sys/fd.h Declare file-descriptor structure sys/fdioctl.h Control floppy-disk I/O sys/fdisk.h Fixed-disk constants and structures sys/filsys.h Structures and constants for super block fperr.h Constants used with floating-point exception codes grp.h Declare group structure sys/hdioctl.h Control hard-disk I/O sys/ino.h Constants and structures for i-nodes sys/inode.h Constants and structures for memory-resident i-nodes sys/io.h Constants and structures used by I/O sys/ipc.h Declarations for process communications l.out.h Object file format sys/lpioctl.h Definitions for line-printer I/O control sys/machine.h Machine-dependent definitions sys/malloc.h Definitions for memory-allocation functions math.h Declare mathematics functions sys/mdata.h Define machine-specific magic numbers mnttab.h Structure for mount table COHERENT Lexicon Page 1
header files Overview header files mon.h Read profile output files sys/mount.h Define the mount table mprec.h Multiple-precision arithmetic sys/msg.h Definitions for message facility sys/msig.h Machine-dependent signals mtab.h Currently mounted file systems sys/mtioctl.h Magnetic-tape I/O control mtype.h List processor code numbers n.out.h Define n.out file structure sys/param.h Define machine-specific parameters path.h Define/declare constants and functions used with path sys/poll.h Define structures/constants used with polling devices sys/proc.h Define structures/constants used with processes pwd.h Declare password structure sys/sched.h Define constants used with scheduling sys/seg.h Definitions used with segmentation sys/sem.h Definitions used by semaphore facility setjmp.h Define setjmp() and longjmp() sgtty.h Definitions used to control terminal I/O sys/shm.h Definitions used with shared memory signal.h Declare signals sys/stat.h Definitions and declarations used to obtain file status stddef.h Declare/define standard definitions stdio.h Declarations and definitions for I/O sys/stream.h Definitions for message facility" string.h Declare string functions termio.h Definitions used with terminal input and output time.h Give time-description structure sys/timeb.h Declare timeb structure timef.h Definitions for user-level timed functions sys/timeout.h Define the timer queue sys/times.h Definitions used with times() system call sys/tty.h Define flags used with tty processing sys/types.h Declare system-specific data types sys/uproc.h Definitions used with user processes utmp.h Login accounting information sys/utsname.h Define utsname structure v7sgtty.h UNIX Version 7-style terminal I/O ***** See Also ***** C language, #include, portability COHERENT Lexicon Page 2