fOpenTempFile (Function)

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fOpenTempFile (Function)

In french: fOuvreFichierTemp

Creates and opens a temporary file. A unique name is given by the system to each temporary file.

New in version 2025

This function is now available for Android applications.

This function is now available in Android widget mode.

This function is now available for iPhone/iPad applications.

This function is now available in iOS widget mode.

Example

// Retrieve the identifier of the temporary file
ResUniqueTempFile = fOpenTempFile(foAutomaticDeletion, "ABC", "C:\MyDirectories")
IF ResUniqueTempFile = -1 THEN 
	Error(ErrorInfo()) 
ELSE
	fWriteLine(ResUniqueTempFile, "Status report of " + DateSys())
	...
END

MyUniqueTempFile is DiskFile
MyUniqueTempFile = fOpenTempFile(foAutomaticDeletion, "ABC", "C:\MyDirectories")
IF ErrorOccurred THEN
	Error(ErrorInfo()) 
ELSE
	fWriteLine(MyUniqueTempFile, "Status report of " + DateSys())
	...
END

// Open a temporary file
MyTemporaryFile is DiskFile
ResOpening is boolean
ResOpening = fOpenTempFile(MyTemporaryFile, foReadWrite, "ABC", "C:\MyDirectories")
IF ResOpening THEN
	...
END

Syntax

Create and open a temporary file Hide the details

<Result> = fOpenTempFile([<Opening mode> [, <Prefix of temporary file> [, <Directory of temporary file>]]])

<Result>: Integer or DiskFile variable

Corresponds to:
an integer:
Identifier of the temporary file. This identifier will be used by all the functions for handling external files.
-1 if an error occurred. To get more details on the error, use ErrorInfo with the errMessage constant.
a variable of type DiskFile. If an error occurs, the ErrorOccurred variable is set to True. To get more details on the error, use ErrorInfo with the errMessage constant.
Not available.

<Opening mode>: Optional constant (or combination of constants)

Constants used to define the opening mode of the file, the access mode to the file and the lock mode of the file.
Lock mode of the file and opening mode of the file:
foAutomaticDeletion The file is locked when opened, and will be automatically deleted when closed (when fClose is called, or when the application is closed).
If the file was opened by another application, it will be automatically deleted by the system when all the applications have closed the file.
Default value.
This constant is not available.
The file will not be deleted if it is being used by another application when it is closed (when fClose is called, or when the application is closed).
foReadLock The other applications cannot read the current file.

This constant is not available.
foWithoutDeletion The file will not be automatically deleted when it is closed.
Default value.
foWriteLock The other applications cannot modify the current file.

This constant is not available.
File access mode. This type is used by fReadLine and fWriteLine to define the type of information to read and write in the external file:
foAnsi Ansi file. This constant is used to manage an Ansi file when the "Use Unicode strings at runtime" mode is enabled in the project configuration.
Mode used by default:
in the WINDEV and WEBDEV projects earlier than version 17.
in the configurations of WINDEV and WEBDEV projects that use the "Use Ansi strings at runtime" mode from version 17.
foUnicode Unicode file. This constant is used to manage a Unicode file when the "Use Ansi strings at runtime" mode is enabled in the project configuration.
Mode used by default:
in the WINDEV Mobile projects regardless of the mode and version used.
in the configurations of WINDEV and WEBDEV projects that use the "Use Unicode strings at runtime" mode from version 17.
This constant is not available.

<Prefix of temporary file>: Optional character string

Prefix (3 letters) for the name of the temporary file. This parameter is used to prefix the name of the temporary file. Only the first three letters will be taken into account.
This parameter can be in Ansi or Unicode format.

<Directory of temporary file>: Optional character string

Full or relative directory of the temporary file (up to 260 characters). A UNC path can be used. This directory name may (or may not) end with the "\" character. This directory must exist. Otherwise, a WLanguage error occurs.
If this parameter is not specified, the default directory will be:
the temporary directory of Windows (if this directory exists on the current computer),
the current directory (if the temporary directory of Windows does not exist on the current computer).
This parameter can be in Ansi or Unicode format.

Creating and opening a temporary file in a DiskFile variable Hide the details

<Result> = fOpenTempFile(<DiskFile> [, <Opening mode> [, <Prefix of temporary file> [, <Directory of temporary file>]]])

<Result>: Boolean

True if the temporary file was created, opened and associated with variable of type DiskFile,
False otherwise. To get more details on the error, use ErrorInfo with the errMessage constant.

<DiskFile>: DiskFile variable

Name of the DiskFile variable to be associated with the manipulated temporary file.

<Opening mode>: Optional constant (or combination of constants)

Constants used to define the opening mode of the file, the access mode to the file and the lock mode of the file.
Lock mode of the file and opening mode of the file:
foAutomaticDeletion The file is locked when opened, and will be automatically deleted when closed (when fClose is called, or when the application is closed).
If the file was opened by another application, it will be automatically deleted by the system when all the applications have closed the file.
Default value.
This constant is not available.
The file will not be deleted if it is being used by another application when it is closed (when fClose is called, or when the application is closed).
foReadLock The other applications cannot read the current file.

This constant is not available.
foWithoutDeletion The file will not be automatically deleted when it is closed.
Default value.
foWriteLock The other applications cannot modify the current file.

This constant is not available.
File access mode. This type is used by fReadLine and fWriteLine to define the type of information to read and write in the external file:
foAnsi Ansi file. This constant is used to manage an Ansi file when the "Use Unicode strings at runtime" mode is enabled in the project configuration.
Mode used by default:
in the WINDEV and WEBDEV projects earlier than version 17.
in the configurations of WINDEV and WEBDEV projects that use the "Use Ansi strings at runtime" mode from version 17.
foUnicode Unicode file. This constant is used to manage a Unicode file when the "Use Ansi strings at runtime" mode is enabled in the project configuration.
Mode used by default:
in the WINDEV Mobile projects regardless of the mode and version used.
in the configurations of WINDEV and WEBDEV projects that use the "Use Unicode strings at runtime" mode from version 17.
This constant is not available.

<Prefix of temporary file>: Optional character string

Prefix (3 letters) for the name of the temporary file. This parameter is used to prefix the name of the temporary file. Only the first three letters will be taken into account.
This parameter can be in Ansi or Unicode format.

<Directory of temporary file>: Optional character string

Full or relative directory of the temporary file (up to 260 characters). A UNC path can be used. This directory name may (or may not) end with the "\" character. This directory must exist. Otherwise, a WLanguage error occurs.
If this parameter is not specified, the default directory will be:
the temporary directory of Windows (if this directory exists on the current computer),
the current directory (if the temporary directory of Windows does not exist on the current computer).
This parameter can be in Ansi or Unicode format.

Remarks

fOpenTempFile throws an error in the following cases:

the specified directory does not exist,
the file is locked by another computer or by another application,
the user has no read or write rights on the file to open.

Business / UI classification: Business Logic

Component: wd300std.dll