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MQL5 ReferenceFile Functions 

File Functions

This is a group of functions for working with files.

For security reasons, work with files is strictly controlled in the MQL5 language. Files with which file operations are conducted using MQL5 means cannot be outside the file sandbox.

There are two directories (with subdirectories) in which working files can be located:

  • terminal_data_folder\MQL5\FILES\ (in the terminal menu select to view "File" - "Open the data directory");
  • the common folder for all the terminals installed on a computer - usually located in the directory C:\Documents and Settings\All Users\Application Data\MetaQuotes\Terminal\Common\Files.

There is a program method to obtain names of these catalogs using the TerminalInfoString() function, using the ENUM_TERMINAL_INFO_STRING enumeration:

//--- Folder that stores the terminal data
   string terminal_data_path=TerminalInfoString(TERMINAL_DATA_PATH);
//--- Common folder for all client terminals
   string common_data_path=TerminalInfoString(TERMINAL_COMMONDATA_PATH);

Work with files from other directories is prohibited.

File functions allow working with so-called "named pipes". To do this, simply call FileOpen() function with appropriate parameters.

Function

Action

FileFindFirst

Starts the search of files in a directory in accordance with the specified filter

FileFindNext

Continues the search started by the FileFindFirst() function

FileFindClose

Closes search handle

FileOpen

Opens a file with a specified name and flag

FileDelete

Deletes a specified file

FileFlush

Writes to a disk all data remaining in the input/output file buffer

FileGetInteger

Gets an integer property of a file

FileIsEnding

Defines the end of a file in the process of reading

FileIsLineEnding

Defines the end of a line in a text file in the process of reading

FileClose

Closes a previously opened file

FileIsExist

Checks the existence of a file

FileCopy

Copies the original file from a local or shared folder to another file

FileMove

Moves or renames a file

FileReadArray

Reads arrays of any type except for string from the file of the BIN type

FileReadBool

Reads from the file of the CSV type a string from the current position till a delimiter (or till the end of a text line) and converts the read string to a value of bool type

FileReadDatetime

Reads from the file of the CSV type a string of one of the formats: "YYYY.MM.DD HH:MM:SS", "YYYY.MM.DD" or "HH:MM:SS" - and converts it into a datetime value

FileReadDouble

Reads a double value from the current position of the file pointer

FileReadFloat

Reads a float value from the current position of the file pointer

FileReadInteger

Reads int, short or char value from the current position of the file pointer

FileReadLong

Reads a long type value from the current position of the file pointer

FileReadNumber

Reads from the file of the CSV type a string from the current position till a delimiter (or til the end of a text line) and converts the read string into double value

FileReadString

Reads a string from the current position of a file pointer from a file

FileReadStruct

Reads the contents from a binary file  into a structure passed as a parameter, from the current position of the file pointer

FileSeek

Moves the position of the file pointer by a specified number of bytes relative to the specified position

FileSize

Returns the size of a corresponding open file

FileTell

Returns the current position of the file pointer of a corresponding open file

FileWrite

Writes data to a file of CSV or TXT type

FileWriteArray

Writes arrays of any type except for string into a file of BIN type

FileWriteDouble

Writes value of the double type from the current position of a file pointer into a binary file

FileWriteFloat

Writes value of the float type from the current position of a file pointer into a binary file

FileWriteInteger

Writes value of the int type from the current position of a file pointer into a binary file

FileWriteLong

Writes value of the long type from the current position of a file pointer into a binary file

FileWriteString

Writes the value of a string parameter into a BIN or TXT file starting from the current position of the file pointer

FileWriteStruct

Writes the contents of a structure passed as a parameter into a binary file, starting from the current position of the file pointer

FolderCreate

Creates a folder in the Files directory

FolderDelete

Removes a selected directory. If the folder is not empty, then it can't be removed

FolderClean

Deletes all files in the specified folder

If the file is opened for writing using FileOpen(), all subfolders specified in the path will be created if there are no such ones.


Updated: 2015.12.03