17. File Functions

You use the file management APL functions to manage files in . These functions include:

  • readFileBinary

  • fileDelete

  • fileMove

  • fileListFiles

  • fileListDirectories

Note!

These functions can only be used for the directories in your local file system.

readFileBinary

Reads a binary file and returns its contents in the  bytearray data format.

bytearray readFileBinary (string  path  )   
ParameterDescription

path

The physical path and name of the file

Returns

The contents as a bytearray

fileDelete

The fileDelete command takes the absolute path of a file and deletes that file.

If the delete is successful, null is returned. If there is an error, an error string is returned.

string fileDelete (string  fileName  )
ParameterDescription

fileName

The absolute path to the file to delete

Returns

Null if the deletion was successful, otherwise an error string


fileMove

The fileMove command takes the path to the file to be moved, and the path to the new destination.

If the move is successful, null is returned. If there is an error, an error string is returned.

string fileMove 
(string fileName ,
 string newFileName )
ParameterDescription

fileName

The absolute path to the file you want to move

newFileName

The absolute path to the new destination of the file

(e.g "/home/files/20110505/movedFile.csv").

Returns

Null if the file was moved successfully, otherwise an error string

fileListFiles

The fileListFiles command lists all files in a given directory.

The command only returns actual files from the directory, it does not return any sub directories or files from sub directories. If there are no files in the given directory, an empty list is returned. If there is an error, null is returned.

list<string> fileListFiles 
(string  directory,
 regex filter (optional)) 
ParameterDescription

directory

The absolute path to the directory for which you want to list files

filter

You can enter a regular expression to filter out which files you want to list. 

Returns

A list (may be empty) of the files in the given directory, or null if there is an error

Note!

The files will not necessarily be listed in alphabetical, or any other specific order.

fileListDirectories

The fileListDirectories command lists all sub directories in a given directory.

The command only returns sub directories in the given directory, it does not return files or sub directories to the sub directories. If there are no directories in the given directory, an empty list is returned. If there is an error, null is returned.

list<string> fileListDirectories 
 (string  directory , 
 regex  filter  (optional))
ParameterDescription

directory

The absolute path to the directory for which you want to list sub directories

filter

You can enter a regular expression to filter out which directories you want to list.

Returns

A list (may be empty) of the directories in the given directory, or null if there is an error