$fexist function

$fexist(path)

The $fexist function checks if the file or folder specified by path exists and returns a value < 0, 0, or > 0 depending on the result:

The result can be used in conditional expressions; see Examples below.

Windows Installer does not support symbolic functions; if you use this function during an MSI build, you will get diagnostic message BLD:U0010 and the result is undefined.

Parameters

All parameters may contain symbolic references; these are resolved before the function is applied. See Examples below.

path

Path of the file or folder whose existence must be checked. path may contain wildcards.

Examples

Here are some usage examples for this function:

<$fexist(<WindowsFolder>\Notepad.exe)>

Returns > 0 if the Notepad.exe file exists; 0 if it does not; and < 0 if it is a folder (which is highly unlikely).

<$fexist(<TempFolder>\*.log)>
<$fexist(<TempFolder>\*.log)> <> 0
<$fexist(<TempFolder>\*.log)> > 0

All conditional expressions evaluate to TRUE if any .log files exist in the user's Temp folder. The first two also evaluate to TRUE if a .log folder exists; the third expression only evaluates to TRUE for proper files.

NOT <$fexist(<TempFolder>\*.log)>

Conditional expression that evaluates to TRUE if no .log files or folders exist in the user's Temp folder.