New WINDEV, WEBDEV and WINDEV Mobile 28 feature!
  • Handling errors
  • Position in the file
  • Managing the ANSI/UNICODE format
WindowsLinuxUniversal Windows 10 AppJavaReports and QueriesUser code (UMC)
WindowsLinuxPHPWEBDEV - Browser code
AndroidAndroid Widget iPhone/iPadIOS WidgetApple WatchMac CatalystUniversal Windows 10 App
Stored procedures
Reads a line in an external file.
WINDEVWEBDEV - Server codeReports and QueriesJavaUser code (UMC)Ajax
// Open an external file
MyFile is DiskFile
MyFile = fOpen("C:\MyDirectories\File.txt", foReadWrite)
IF NOT ErrorOccurred THEN
// Read a line in this file
ResRead = MyFile.ReadLine()
<Result> = <File used>.ReadLine([<Separator>])
<Result>: Character string or UNICODE character string
  • Line read in an external file.
  • EOT constant if the end of file has been reached.
  • Empty string ("") if an error occurred. In this case, the ErrorOccurred variable is set to True.
Remark: A line ends with a CR character (Carriage Return).
<File used>: DiskFile variable
Name of the DiskFile variable initialized with fOpen or fCreate.
<Separator>: Character string
Separator used between the lines. The default separator is the Carriage Return (CR).
New in version 28
AndroidAndroid Widget Java This parameter is now available.

Handling errors

<DiskFile variable>.ReadLine throws an error in the following cases:
  • the file is not opened,
  • the file is not accessible in read mode,
  • the file is locked by another computer or by another application. <DiskFile variable>.Unlock is used to unlock an external file.

Position in the file

When opening a file, the current position corresponds to:
  • the first file byte (by default),
  • the last byte of the file is the file is opened in "addition" mode (foAdd constant).
This position can be modified by <DiskFile variable>.Seek.
<DiskFile variable>.ReadLine reads the specified elements from the current position. Once <DiskFile variable>.ReadLine has been executed, the current position is set to the last byte read. <DiskFile variable>.ReadLine returns the EOT constant if the end of the file has been reached.
WINDEVWEBDEV - Server codeReports and QueriesUser code (UMC)Ajax

Managing the ANSI/UNICODE format

The <DiskFile variable>.ReadLine function reads:
  • a Unicode string in a Unicode file.
  • an Ansi string in an Ansi file.
The file is created or opened with fCreate/fOpen by specifying the file type.
Depending on the format of the external file used, some conversions are required once a character string was read in an external file:
Current computer
External file
in ANSI format
(fOpen or fCreate associated with the foAnsi constant)
External file
in UNICODE format
(fOpen or fCreate associated with the foUnicode constant)
<DiskFile variable>.ReadLine functionPC running WindowsRead operation in ANSI format
Conversion to UNICODE possible with <String type>.AnsiToUnicode
MobileRead operation in UNICODE format
Conversion to ANSI possible with UnicodeToAnsi

Remark: If the result of <DiskFile variable>.ReadLine of an ANSI file is assigned to a UNICODE string (and vice versa), the conversion will be implicitly performed.
For more details, see Managing UNICODE
Business / UI classification: Business Logic
Component: wd280std.dll
Minimum version required
  • Version 28
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