FileOpen [AHK_L 42+]

Opens a file.

file := FileOpen(Filename, Flags [, Encoding])

Parameters

FilenameThe path of the file to open, which is assumed to be in A_WorkingDir if an absolute path isn't specified.
FlagsEither [in AHK_L 54+] a string of characters indicating the desired access mode followed by other options (with optional spaces or tabs in between); or [in AHK_L 42+] a combination (sum) of numeric flags. Supported values are described in the table below.
EncodingThe code page to use for text I/O if the file does not contain a UTF-8 or UTF-16 byte order mark.
If omitted, the current value of A_FileEncoding is used.

Flags

Access modes (mutually-exclusive)
r0Read: Fails if the file doesn't exist.
w1Write: Creates a new file, overwriting any existing file.
a2Append: Creates a new file if the file didn't exist, otherwise moves the file pointer to the end of the file.
rw3Read/Write: Creates a new file if the file didn't exist.
hIndicates that Filename is a file handle to wrap in an object. Sharing mode flags are ignored. The file handle is not closed automatically when the file object is destroyed and calling Close has no effect. Note that Seek, Tell and Length should not be used if Filename is a handle to a nonseeking device such as a pipe or a communications device.
Sharing mode flags
-rwdLocks the file for read, write and/or delete access. Any combination of r, w and d may be used. Specifying - is the same as specifying -rwd. If omitted entirely, the default is to share all access.
0If Flags is numeric, the absence of sharing mode flags causes the file to be locked.
0x100Shares read access.
0x200Shares write access.
0x400Shares delete access.
End of line (EOL) options
`n4Replace `r`n with `n when reading and `n with `r`n when writing.
`r8Replace standalone `r with `n when reading.

Return Value

If the file is opened successfully, the return value is a File object.

If the function fails, the return value is 0 and [in AHK_L 54+] A_LastError contains an error code.

Use if file or IsObject(file) to check if the function succeeded.

Remarks

When a UTF-8 or UTF-16 file is created, a byte order mark is written to the file unless Encoding (or A_FileEncoding if Encoding is omitted) contains "UTF-8-RAW" or "UTF-16-RAW".

Related

FileEncoding, File Object, FileRead

Examples

; Open the script in read-only mode and read its first line:
file := FileOpen(A_ScriptFullPath, "r")
MsgBox % file.ReadLine()

; Open a console window for this demonstration:
DllCall("AllocConsole")
; Open the application's stdin/stdout handles in newline-translated mode.
stdin  := FileOpen(DllCall("GetStdHandle", "int", -10, "ptr"), "h `n")
stdout := FileOpen(DllCall("GetStdHandle", "int", -11, "ptr"), "h `n")
stdout.Write("Enter your query.`n\> ")
stdout.Read(0) ; Flush the write buffer.
query := RTrim(stdin.ReadLine(), "`n")
stdout.WriteLine("Your query was '" query "'. Have a nice day.")
stdout.Read(0) ; Flush the write buffer.
Sleep 5000