SYSTEM

Portability Function: Sends a command to the shell as if it had been typed at the command line.

Module: USE DFPORT

Syntax

result = SYSTEM (string)

string
(Input) Character*(*). Operating system command.

Results:

The result is of type INTEGER(4). The result is the exit status of the shell command. If -1, use IERRNO to retrieve the error. Errors can be one of the following:

• E2BIG: The argument list is too long.
• ENOENT: The command interpreter cannot be found.
• ENOEXEC: The command interpreter file has an invalid format and is not executable.
• ENOMEM: Not enough system resources are available to execute the command.

On WNT systems, the calling process waits until the command terminates. On W9* systems, the calling process does not currently wait in all cases; however, this may change in future implementations. To insure compatibility and consistent behavior, an image can be invoked directly by using the Win32 API CreateProcess( ) in your Fortran code.

Commands run with the SYSTEM routine are run in a separate shell. Defaults set with the SYSTEM function, such as current working directory or environment variables, do not affect the environment the calling program runs in.

The command line character limit for the SYSTEM function is the same limit that your operating system command interpreter accepts.

Compatibility

CONSOLE STANDARD GRAPHICS QUICKWIN GRAPHICS WINDOWS DLL LIB

See Also: SYSTEMQQ

Example

   USE DFPORT
   INTEGER(4) I, errnum
   I = SYSTEM("dir > file.lst")
   If (I .eq. -1) then
     errnum = ierrno( )
     print *, 'Error ', errnum
   end if
   END
还有在fortran内部给外部文件改名字：

integer(4) function RENAME( from , to )
改變檔案名稱，改名成功時傳回0。
character*(*) from 原始檔名
character*(*) to 新檔名
程式執行時，可以經由函式SYSTEM 再去呼叫另外一個程式來執行。