FORK(S)                  XENIX System V                   FORK(S)



     Name
          fork - Creates a new process.

     Syntax
          int fork ()

     Description
          fork causes creation of a new process.  The new process
          (child process) is an exact copy of the calling process
          (parent process).  This means the child process inherits the
          following attributes from the parent process:

               environment

               close-on-exec flag (see exec(S))

               signal handling settings (that is, SIG_DFL, SIG_IGN,
               function address)

               set-user-ID mode bit

               set-group-ID mode bit

               process group ID

               tty group ID (see exit(S) and signal(S))

               current working directory

               root directory

               file mode creation mask (see umask(S))

               file size limit (see ulimit(S))

          The child process differs from the parent process in the
          following ways:

               The child process has a unique process ID.

               The child process has a different parent process ID
               (i.e., the process ID of the parent process).

               The child process has its own copy of the parent's file
               descriptors.  Each of the child's file descriptors
               shares a common file pointer with the corresponding
               file descriptor of the parent.

               All semadj values are cleared (see semop(S)).

               The child process' utime, stime, cutime, and cstime are
               set to 0; see times(S).



     Page 1                                           (printed 8/7/87)

     FORK(S)                  XENIX System V                   FORK(S)



               The time left on the parent's alarm clock is not passed
               on to the child.

          fork returns a value of 0 to the child process.

          fork returns the process ID of the child process to the
          parent process.

          fork will fail and no child process will be created if one
          or more of the following are true:

               The system-imposed limit on the total number of
               processes under execution would be exceeded.  [EAGAIN]

               The system-imposed limit on the total number of
               processes under execution by a single user would be
               exceeded.  [EAGAIN]

               Not enough memory is available to create the forked
               image.  [ENOMEM]

     Return Value
          Upon successful completion, fork returns a value of 0 to the
          child process and returns the process ID of the child
          process to the parent process.  Otherwise, a value of -1 is
          returned to the parent process, no child process is created,
          and errno is set to indicate the error.

     See Also
          exec(S), sdget(S), semop(S), shmop(S), wait(S)

























     Page 2                                           (printed 8/7/87)