fWriteLine (Function)

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Functions for managing external files

Operating mode in Windows Vista (and later)

Position in the file

Managing the ANSI/UNICODE format

Related examples

See also

fWriteLine (Function)

In french: fEcritLigne

Writes a line into an external file. The characters required to go to the next line are automatically inserted at the end of the added line.

Only the ANSI format is supported.

Versions 15 and later

This function is now available for the Android applications.

New in version 15

This function is now available for the Android applications.

Versions 16 and later

This function is now available for the Windows Phone applications.

New in version 16

This function is now available for the Windows Phone applications.

Versions 17 and later

This function is now available for the iPhone/iPad applications.

New in version 17

This function is now available for the iPhone/iPad applications.

Versions 18 and later

This function is now available in Android Widget mode.

This function is now available in Windows Store apps mode.

New in version 18

This function is now available in Android Widget mode.

This function is now available in Windows Store apps mode.

This function is now available in Android Widget mode.

This function is now available in Windows Store apps mode.

Versions 21 and later

This function is now available in Universal Windows 10 App mode.

New in version 21

This function is now available in Universal Windows 10 App mode.

Example

See additional examples

// Open an external file
FileID = fOpen("C:\MyDirectories\File.txt", foReadWrite)
IF FileID <> -1 THEN
// Write a line into this file
ResWrite = fWriteLine(FileID, "Status report of meeting")
IF ResWrite = False THEN
...
END
END

// Open an external file
FileID = fOpen("\MyDirectories\File.txt", foReadWrite)
IF FileID <> -1 THEN
// Write a line into this file
ResWrite = fWriteLine(FileID, "Status report of meeting")
IF ResWrite = False THEN
...
END
END

Syntax

Writing a line into an external file Hide the details

<Result> = fWriteLine(<File identifier> , <Line to write>)

<Result>: Boolean

True if the write operation was performed into the specified file,
False if an error occurred. To find out the error details, use ErrorInfo associated with the errMessage constant.

<File identifier>: Integer

Identifier of the file to use, defined by fOpen or fCreate.
This parameter must be a variant.

<Line to write>: Character string (with quotes)

Line that must be written into the file (up to 2GB).

Writing a fixed-length line into an external file (speeds up the write operation) Hide the details

<Result> = fWriteLine(<File identifier> , <Address of line to write> , <Size to write>)

<Result>: Boolean

True if the write operation was performed into the specified file,
False if an error occurred. To find out the error details, use ErrorInfo associated with the errMessage constant.

<File identifier>: Integer

Identifier of the file to use, defined by fOpen or fCreate.

<Address of line to write>: Address

Address of the line that must be written into the file.

<Size to write>: Integer

Size in bytes (characters) of the line that must be written (up to 2GB).
This parameter must be less than or equal to the real size of the wine written into the external file. For example, if the size of the line to write is equal to 100 bytes, <Size to write> must be less than or equal to 100 bytes.
If this parameter is less than the real size of the written line, only the specified number of bytes will be written into the text file. The line will be truncated.
Reminder: In UNICODE, each character occupies two memory bytes.

Remarks

Managing errors

fWriteLine generates an error in the following cases:

the file is not opened,
the file is not accessible in write mode,
the file is locked by another computer or by another application,
no disk space is available.

Caution: fWriteLine can only be used on text files. This function does not support the binary 0 (the write operation is stopped).

Operating mode in Windows Vista (and later)

If this function does not operate properly in Windows Vista (and later), check whether the file or directory used is not in one of the system directories (Windows directory or "Program Files" directory).

Indeed, in Windows Vista (and later), with the UAC mechanism (User Account Control) enabled, you must have the administrator privileges to handle and/or modify the files or directories in the system directories (Windows directory or "Program Files" directory).

Programming tip: To handle and/or modify the files or directories without administrator privileges, you should:

avoid writing into the Windows directory or into the "Program Files" directory,
use the system directory corresponding to the application (returned by SysDir associated with the srCommonAppData constant).

Remark: In Windows Vista (and later), the virtualization mechanism is used to make the applications compatible with Vista. If the file is created in a system directory without having sufficient rights, this file will actually be created in another directory (C:\Users\<LOGIN>AppData\Local\VirtualStore\Windows\). In this case, the file cannot be shared between several applications.

Position in the file

When opening a file, the current position corresponds to:

the first byte of the file (by default),
the last byte of the file is the file is opened in "addition" mode (foAdd constant).

This position can be modified by fSeek.

fWriteLine writes the specified elements from the current position. Once fWriteLine has been run, the current position corresponds to the last byte written.

Managing the ANSI/UNICODE format

fWriteLine is used to write:

a Unicode string into a Unicode file.
an Ansi string into an Ansi file.

The file was created or opened by fCreate/fOpen while specifying the file type.

Remarks:

The size to write into Unicode file a must be multiplied by two compared to an ANSI file.

If a character string in ANSI format is written into a UNICODE file (and conversely), the conversion will be implicitly performed.


	Format of the string passed in parameter	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)
fWriteLine	ANSI	No conversion is required before the write operation	Automatic conversion of the string before the write operation
fWriteLine	UNICODE	Automatic conversion of the string before the write operation	No conversion is required before the write operation

In the WINDEV and WEBDEV projects, in version 16 and in version 17 ("Use the ANSI strings at run time" option in the description of the project configuration), the opening mode used by default is foAnsi (1st column).

In the WINDEV and WEBDEV projects, in version 17 and in Unicode mode ("Use the UNICODE strings at run time" option in the description of the project configuration), the opening mode used by default is foUnicode (second column).

In the WINDEV Mobile projects, regardless of the version and mode, the opening mode used by default is foUnicode (second column).

See Managing the UNICODE for more details

Related Examples:

Unit examples (WINDEV): Handling text files

[ + ] Handling "text" files with WINDEV:
- Create a text file
- Write into a text file
- Read in a text file

Unit examples (WEBDEV): Handling text files

[ + ] This example explains how to handle "non HFSQL" files with WEBDEV and it allows you to:
- Create a text file
- Write into a text file
- Read in a text file

Unit examples (WINDEV Mobile): Handling text files

[ + ] Handling external "text" files:
- Create a text file
- Write into a text file
- Read in a text file

Unit examples (WINDEV): The TableTo functions

[ + ] Exporting table data with the WLanguage functions.
The following topics are presented in this example:
1/ interfacing with Word and Excel
2/ sending data to the clipboard
3/ generating a text file
This example explains how to export the content of a table to a Word document, an Excel workbook, the clipboard or a text file via the following WLanguage functions: TableToWord, TableToExcel, ToClipboard, TableToText.

Component : wd260std.dll