HEADER FILE “process.h”

process.h

process.h is a C header file which contains function declarations and macros used in working with threads and processes. Most C compilers that target DOS, Windows 3.1x, Win32, OS/2, Novell NetWare or DOS extenders supply this header and the library functions in their C library. Neither the header file nor most of the functions are defined by either the ANSI/ISO C standard or by POSIX.

History[edit]

Microsoft’s version of the file dates back to at least 1985, according to its copyright statement.[1] An early reference to the file was in a post on the net.micro.pc usenet on Oct-26-1986.[2] The compiler used was Microsoft C compiler version 3.0. The Lattice C compiler version 3.30 (Aug-24-1988) did not have such a header file, but offered similar functions. Borland provided the header in their Turbo C compiler version 2.01. The C Ware-Personal C compiler version 1.2c (June 1989) had only the ANSI headers.

Member functions[edit]

Name Description Notes
execl, execle, execlp, execlpe load and execute a new child process by placing it in memory previously occupied by the parent process. Parameters are passed individually. DOS,Win,OS/2,POSIX
execv, execve, execvp, execvpe load and execute a new child process by placing it in memory previously occupied by the parent process. Parameters are passed as an array of pointers. DOS,Win,OS/2,POSIX
spawnl, spawnle, spawnlp, spawnlpe load and execute a new child process. Parameters are passed individually. DOS,Win,OS/2
spawnv, spawnve, spawnvp, spawnvpe load and execute a new child process. Parameters are passed as an array of pointers. DOS,Win,OS/2
beginthread, beginthreadNT creates a new thread of execution within the current process. Win,OS/2
endthread terminates a thread created by beginthread. Win,OS/2
getpid returns the process identifier. DOS,Win,OS/2
cexit restore interrupt vectors altered by the startup code. DOS,Win,OS/2

Member constants[edit]

Name Description Notes OS
_P_WAIT Suspends parent process until the child process has finished executing. synchronous spawn. MS-DOS,Win32,OS/2
_P_NOWAIT, _P_NOWAITO Continues to execute calling process concurrently with new process. asynchronous spawn. Win32,OS/2
_P_OVERLAY Overlays parent process with child, which destroys the parent. has the same effect as theexec* functions. MS-DOS,Win32,OS/2
_P_DETACH The child is run in background without access to the console or keyboard. Calls to _cwait upon the new process will fail. Asynchronous spawn. Win32,OS/2
_WAIT_CHILD used as cwait action. Obsolete on Win32. MS-DOS,OS/2
_WAIT_GRANDCHILD used as cwait action. Obsolete on Win32. MS-DOS,OS/2

Implementations[edit]

Given the fact there is no standard on which to base the implementation, the functions declared by process.h differ, depending on the compiler in use. Below is a list of compilers which provide process.h.

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