PXFFORK (L*X, M*X)

POSIX Subroutine: Creates a child process that differs from the parent process only in its PID.

Module

USE IFPOSIX

Syntax

CALL PXFFORK (ipid,ierror)

ipid

(Output) INTEGER(4). The returned PID of the new child process.

ierror

(Output) INTEGER(4). The error status.

If successful, ierror is set to zero; otherwise, an error code.

The PXFFORK subroutine creates a child process that differs from the parent process only in its PID. If successful, the PID of the child process is returned in the parent's thread of execution, and a zero is returned in the child's thread of execution. Otherwise, a -1 is returned in the parent's context and no child process is created.

Example

program t1

use ifposix

integer(4) ipid, istat, ierror, ipid_ret, istat_ret

print *," the child process will be born"

call PXFFORK(IPID, IERROR)

call PXFGETPID(IPID_RET,IERROR)

if(IPID.EQ.0) then

print *," I am a child process"

print *," My child's pid is", IPID_RET

call PXFGETPPID(IPID_RET,IERROR)

print *," The pid of my parent is",IPID_RET

print *," Now I have exited with code 0xABCD"

call PXFEXIT(Z'ABCD')

else

print *," I am a parent process"

print *," My parent pid is ", IPID_RET

print *," I am creating the process with pid", IPID

print *," Now I am waiting for the end of the child process"

call PXFWAIT(ISTAT, IPID_RET, IERROR)

print *," The child with pid ", IPID_RET," has exited"

if( PXFWIFEXITED(ISTAT) ) then

print *, " The child exited normally"

istat_ret = IPXFWEXITSTATUS(ISTAT)

print 10," The low byte of the child exit code is", istat_ret

end if

end if

10 FORMAT (A,Z)

end program

See Also