CHECKFILE Function

Determines if a file can be read from or written to.

Usage

status = CHECKFILE(filename)

Input Paramters

A string containing the name of a file. If a pathname is not included, the function looks in the current directory for the file.

Returned Value

A value indicating if the file can be used for the given operation.


1	Indicates the file can be used for the specified operation.
0	Indicates the file cannot be used.

Keywords

(UNIX Only) A string containing the expanded filename is returned. Constructs such as ~user and $ENV_VAR are expanded.

Is_Dir Returns a 1 if filename is a directory.

Read If specified and nonzero, the function verifies that the file is readable.

NOTE: Either the Read keyword or the Write keyword must be specified.

Size

Returns the size of the file in bytes.

Write If specified and nonzero, the function verifies that the file is writable.

Discussion

You must supply either the Read or Write keyword. If neither of these keywords is supplied, the CHECKFILE function returns 0.

Example

status = CHECKFILE(!Data_dir + 'head.img', /Read)

PRINT, status 1

status = CHECKFILE(!Data_dir + 'new_head.img', /Write)

PRINT, status 1

status = CHECKFILE(!Data_dir + 'head_not.img', /Read)

PRINT, status 0

; Check the status of a file.

status = CHECKFILE(!Dir, /Read, Is_Dir = isdir)

PRINT, status 1

; Determine if a directory exists.

status = CHECKFILE(!Data_dir + 'head.img', Size = sz)

PRINT, sz 262144

; Check the size of a file.

See Also

PV

-WAVE GUI Application Developer's Guide

doc@boulder.vni.com

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