The FILE_INFO function returns status information about a specified file or files.
Examples
To get information for dist.pro within the IDL library:
HELP,/STRUCTURE, FILE_INFO(FILEPATH('dist.pro', $
SUBDIRECTORY = 'lib'))
Executing the above command will produce output similar to:
** Structure FILE_INFO, 21 tags, length=72:
NAME STRING '/usr/local/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 438
ATIME LONG64 970241431
CTIME LONG64 970241595
MTIME LONG64 969980845
SIZE LONG64 1717
Syntax
Result = FILE_INFO(Path [, /NOEXPAND_PATH] )
Return Value
The FILE_INFO function returns a structure expression of type FILE_INFO containing status information about the specified file or files. The result will contain one structure for each element in the Path argument.
Fields of the FILE_INFO Structure
The FILE_INFO structure consists of the following fields:
|
Field Name |
Meaning |
|
NAME |
The name of the file.
|
|
EXISTS |
True (1) if the file exists. False (0) if it does not exist.
|
|
READ |
True (1) if the file is exists and is readable by the user. False (0) if it is not readable.
|
|
WRITE |
True (1) if the file exists and is writable by the user. False (0) if it is not writable.
|
|
EXECUTE |
True (1) if the file exists and is executable by the user. False (0) if it is not executable. The source of this information differs between operating systems:
UNIX: IDL checks the execute bit maintained by the operating system.
Microsoft Windows: The determination is made on the basis of the file name extension (e.g. .exe).
|
|
REGULAR |
True (1) if the file exists and is a regular disk file and not a directory, pipe, socket, or other special file type. False (0) if it is not a regular disk file (it maybe a directory, pipe, socket, or other special file type).
|
|
DIRECTORY |
True (1) if the file exists and is a directory. False (0) if it is not a directory.
|
|
BLOCK_SPECIAL |
True (1) if the file exists and is a UNIX block special device. On non-UNIX operating systems, this field will always be False (0).
|
|
CHARACTER_SPECIAL
|
True (1) if the file exists and is a UNIX character special device. On non-UNIX operating systems, this field will always be False (0).
|
|
NAMED_PIPE |
True (1) if the file exists and is a UNIX named pipe (fifo) device. On non-UNIX operating systems, this field will always be False (0).
|
|
SETGID |
True (1) if the file exists and has its Set-Group-ID bit set. On non-UNIX operating systems, this field will always be False (0).
|
|
SETUID |
True (1) if the file exists and has its Set-User-ID bit set. On non-UNIX operating systems, this field will always be False (0).
|
|
SOCKET |
True (1) if the file exists and is a UNIX domain socket. On non-UNIX operating systems, this field will always be False (0).
|
|
STICKY_BIT |
True (1) if the file exists and has its sticky bit set. On non-UNIX operating systems, this field will always be False (0).
|
|
SYMLINK |
True (1) if the file exists and is a UNIX symbolic link. On non-UNIX operating systems, this field will always be False (0).
|
|
DANGLING_SYMLINK
|
True (1) if the file exists and is a UNIX symbolic link that points at a non-existent file. On non-UNIX operating systems, this field will always be False (0).
|
| MODE |
File permissions in octal notation. See Numeric Notation on Wikipedia.org for more information. |
|
ATIME, CTIME, MTIME
|
The date of last access, date of file status change, and date of last modification given in seconds since 1 January 1970 UTC. Use the SYSTIME function to convert these dates into a textual representation. On Windows platforms the CTIME field will contain the file creation time. On Unix platforms the CTIME field will contain the time of the last file status change.
Note: Some file systems do not maintain all of these dates (e.g. MS DOS FAT file systems), and may return 0. On some non-UNIX operating systems, access time is not maintained, and ATIME and MTIME will always return the same date.
Tip: If you only need the file modification time, it is faster to use the FILE_MODTIME function instead.
|
|
SIZE |
The current length of the file in bytes. If Path is not to a regular file (possibly to a directory, pipe, socket, or other special file type), the value of SIZE will not contain any useful information.
|
Arguments
Path
A string or string array containing the path or paths to the file or files about which information is required.
Note: Windows platforms have a file name length limit of 260 characters, while Unix platforms have a limit of 1024 characters. File names longer than this limit will return a structure with the EXISTS field set to zero.
Note: If the file pointed to by Path is currently open, use FSTAT to query for its info. FILE_INFO does not always obtain information on changes that have occurred in a file that is currently open. FSTAT, however, maintains current information on files it opens.
Keywords
NOEXPAND_PATH
If specified, FILE_INFO uses Path exactly as specified, without applying the usual file path expansion.
Version History
See Also
FILE_MODTIME, FILE_TEST, FSTAT, General File Access