Intel® Fortran Compiler Classic and Intel® Fortran Compiler Developer Guide and Reference

ID 767251
Date 7/13/2023
Public

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PXFFORK

POSIX Subroutine: Creates a child process that differs from the parent process only in its PID. This routine is only available for Linux and macOS.

Module

USE IFPOSIX

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