Returning Information About a File

Using IDL: Getting Information About Files and Data

Returning Information About a File

You can use the FILE_INFO function to retrieve information about a file that is not currently open. To get information about an open file (for which there is an IDL Logical Unit Number), use the HELP procedure or the FSTAT function. See Returning Information About a File Unit.

The FILE_INFO function returns a structure expression of type FILE_INFO containing information about the file. For example, get information on dist.pro:

HELP,/STRUCTURE, FILE_INFO(FILEPATH('dist.pro', 
SUBDIRECTORY='lib'))

The above command will produce output similar to:

** Structure FILE_INFO, 21 tags, length=72:  
        NAME            STRING   '/usr/local/itt/idl/lib/dist.pro'  
        EXISTS          BYTE         1  
        READ            BYTE         1  
        WRITE           BYTE         0  
        EXECUTE         BYTE         0  
        REGULAR         BYTE         1  
        DIRECTORY       BYTE         0  
        BLOCK_SPECIAL   BYTE         0  
        CHARACTER_SPECIAL  
                        BYTE         0  
        NAMED_PIPE      BYTE         0  
        SETGID          BYTE         0  
        SETUID          BYTE         0  
        SOCKET          BYTE         0  
        STICKY_BIT      BYTE         0  
        SYMLINK         BYTE         0  
        DANGLING_SYMLINK  
                        BYTE         0  
        MODE            LONG               420  
        ATIME           LONG64                 970241431  
        CTIME           LONG64                 970241595  
        MTIME           LONG64                 969980845  
        SIZE            LONG64                      1717

The fields of the FILE_INFO structure provide various information about the file, such as the size of the file, and the dates of last access, creation, and last modification. For more information on the fields of the FILE_INFO structure, see FILE_INFO. See FILE_LINES for information on how to retrieve the number of lines of text in a file.

IDL Online Help (March 06, 2007)