Make a subdirectory in F90

[TommyCee]

Does anyone know whether it's possible to create ("open") a subdirectory in the working directory of a project at runtime? What I'd like to do is, early in the program, create the subdirctory if it's non-existent. If it already exists (e.g., from an earlier execution), ignore and move on.

Output files will then opened on a path that includes this subdirctory.

I researched this and did not see any such possibility.

[Brian_Allison]

if not exist (dir) mkdir (dir)

Make sure to tab this entry

[Steven_L_Intel1]

MAKEDIRQQ - see the description in the Language Reference.

[TommyCee]

Could I please get a bit more help. Some syntax?
I find no refs for the command mkdir in any of my Visual Fortran manuals.

The line:
mkdir (Output)

and

if (.not exist. (Output)) mkdir (Output)

trigger an error:
Syntax error, found END-OF-STATEMENT when expecting one of: ( % . = =>

[mecej4]

You need to recognize that concepts such as directories are external to Fortran. Therefore, there are no "commands" or "verbs" in Fortran to manipulate or enquire about directories.

However, compilers usually provide Fortran callable library routines to provide a bridge between Fortran code and operating system services. These libraries are compiler/OS specific, and are described in the compiler documentation, not in a Fortran language reference book.

[Steven_L_Intel1]

The suggestion for using "mkdir" would mean that you'd have to use SYSTEMQQ or RUNQQ to executa a command line. You don't need to do that - as I wrote above, MAKEDIRQQ does exactly what you want.

USE IFPORT
if (.not. MAKEDIRQQ("subdir")) then
print *, "Failed to create subdirectory"
end if

[TommyCee]

Thanks Steve - that's just the nudge what I needed. That was huge!

[bash]use DFLIB
LOGICAL(4) result
result = MakeDirQQ('mynewdir')

IF (result) THEN
  WRITE (*,*) 'New subdirectory successfully created'
ELSE
  WRITE (*,*) 'Failed to create subdirectory'
END IF
END[/bash]

[Les_Neilson]

You can also use the INQUIRE statement to see if the directory exists.

logical:: L_EXISTS
character(12) :: C_DIRSPEC
C_DIRSPEC = "subdirectory"
inquire(directory=C_DIRSPEC, exist=L_EXISTS)

if(.not.L_EXISTS) then
print *,"The directory ",C_DIRSPEC," does not exist"
endif

Les

[Steven_L_Intel1]

Note that the DIRECTORY keyword to INQUIRE is our extension to the standard.