查看“Fortran程序调用”的源代码

先要给要调用的Fortran程序写一个接口，例

接口程序：

 SUBROUTINE SUM_ARRAY(argc, argv)  !Called by IDL
 INTEGER*4 argc, argv(*)           !Argc and Argv are integers
 j = LOC(argc)         !Obtains the number of arguments (argc)
                      !Because argc is passed by VALUE.
 ;
 ! Call subroutine SUM_ARRAY1, converting the IDL parameters
 ! to standard Fortran, passed by reference arguments:
 CALL SUM_ARRAY1(%VAL(argv(1)), %VAL(argv(2)), %VAL(argv(3)))
 RETURN
 END

调用程序：

 ! This subroutine is called by SUM_ARRAY and has no  IDL specific code.
 SUBROUTINE SUM_ARRAY1(array, n, sum)
 INTEGER*4 n
 REAL*4 array(n), sum
 sum=0.0
 DO i=1,n
 sum = sum + array(i)
 ENDDO
 RETURN
 END

编译生成动态链接库文件
 ifort -shared -fpic  SUM_ARRAY.f SUM_ARRAY1.f -o example1.so
 -shared   produce a shared object
 -fpic  generate position independent code (-fno-pic/-fno-PIC is DEFAULT)

然后在IDL中的调用方法如下
 X = FINDGEN(10) ; Make an array.
 sum = 0.0
 S = CALL_EXTERNAL('example1.so', 'sum_array_', X, N_ELEMENTS(X), sum)