FileOpen
Opens an existing file for reading and writing.
Note: The file functions should not be used to implement configuration files. It is encouraged to use the XML functions for this instead.
Syntax
file fileOpen ( string filename [, bool readonly = false, resource root = getThisResource ()] )
Required Arguments
- filename: The name of the file you wish to open.
Optional Arguments
- readonly: By default, the file is opened with reading and writing access. You can specify true for this parameter if you only need reading access.
- root: The resource in whose directory the file is located. Defaults to the resource calling the function.
Returns
If successful, returns a file handle for the file. Otherwise returns false (f.e. if the file doesn't exist).
Example
This example opens the file test.txt and outputs its contents to the console.
local hFile = fileOpen("test.txt", true) -- attempt to open the file (read only)
if hFile then -- check if it was successfully opened
local buffer
while not fileIsEOF(hFile) do -- as long as we're not at the end of the file...
buffer = fileRead(hFile, 500) -- ... read the next 500 bytes...
outputConsole(buffer) -- ... and output them to the console
end
fileClose(hFile) -- close the file once we're done with it
else
outputConsole("Unable to open test.txt")
end
Notice that you can't simply do buffer = fileRead("test.txt", 500). Instead, file functions operate on a file handle, which is a special object representing an open file. fileOpen gives us such a handle.
It is also important to remember to close a file after you've finished all your operations on it, especially if you've been writing to the file. If you don't close a file and your resource crashes, all changes to the file may be lost.
See Also
- fileClose
- fileCopy
- fileCreate
- fileDelete
- fileExists
- fileFlush
- fileGetPath
- fileGetPos
- fileGetSize
- fileIsEOF
- fileOpen
- fileRead
- fileRename
- fileSetPos
- fileWrite