wxJavaScript

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wxFile

^{generated from ../src/mod_io/file.cpp}

A wxFile performs raw file I/O. This is a very small class designed to minimize the overhead of using it - in fact, there is hardly any overhead at all, but using it brings you automatic error checking and hides differences between platforms. wxFile is a wrapper around a file descriptor, while wxFFile is a wrapper around the FILE structure.

Constants

FileAccess

Name	Description
IRUSR
IWUSR
IXUSR
IRGRP
IWGRP
IXGRP
IROTH
IWOTH
IXOTH
DEFAULT

FileDescriptor

Name	Description
fd_stdin
fd_stdout
fd_stderr

Mode

Name	Description
read
write
read_write
write_append
write_excl

wxFileKind

Name	Description
KIND_UNKNOWN
KIND_DISK
KIND_TERMINAL
KIND_PIPE

wxSeekMode

Name	Description
FromCurrent
FromStart
FromEnd

wxSeekMode is ported as a separate JavaScript object.

Class Methods

access

access(Filename, 
       Mode) : Boolean
 

Name	Type	Default	Description
Filename	String		Filename to check
Mode	Mode		File mode

This function verifies if we may access the given file in specified mode. Only values of read or write really make sense here.

exists

exists(Filename) : Boolean
 

Name	Type	Default	Description
Filename	String

Returns true when the file exists.

Constructor

wxFile

wxFile()
 

wxFile(FileName, 
       Mode = wxFile.read)
 

Name	Type	Default	Description
FileName	String		The filename
Mode	OpenMode	wxFile.read	The mode in which to open the file. See Mode.

Constructs a new wxFile object. When a filename is passed, The file is opened, and you can check whether the operation was successful or not by checking opened.

Properties

Name	Type	Description
eof	Boolean	Returns true when end of file is reached. When the file is not open, undefined is returned.
length	Integer	Returns the length of the file. When the file is not open, undefined is returned.
opened	Boolean	Returns true when the file is open.
tell	Integer	Returns the current position or -1. When the file is not open, undefined is returned.

Methods

attach

attach(Fd)
 

Name	Type	Default	Description
Fd	Integer		A file descriptor

Attaches an existing file descriptor to the wxFile object. Example of predefined file descriptors are 0, 1 and 2 which correspond to stdin, stdout and stderr (and have symbolic names of wxFile.fd_stdin, wxFile.fd_stdout and wxFile.fd_stderr).

close

close()
 

Closes the file.

create

create(FileName, 
       Overwrite = false, 
       Access = wxFile.DEFAULT) : Boolean
 

Name	Type	Default	Description
FileName	String		The name of the file to create.
Overwrite	Boolean	false	Overwrite the file when it already exist? The default is false.
Access	Integer	wxFile.DEFAULT

Creates a file for writing.

detach

detach()
 

Get back a file descriptor from wxFile object - the caller is responsible for closing the file if this descriptor is opened. opened will return false after call to detach.

flush

flush()
 

Flushes the file.

open

open(FileName, 
     Mode = wxFile.read) : Boolean
 

Name	Type	Default	Description
FileName	String		The name of the file to open
Mode	Integer	wxFile.read

Opens a file.

read

read(Count) : wxMemoryBuffer
 

Name	Type	Default	Description
Count	Integer		The number of bytes to read.

Reads the specified number of bytes and returns a buffer.

seek

seek(Offset, 
     Mode = wxFile.FromStart) : Integer
 

Name	Type	Default	Description
Offset	Integer		Offset to seek to.
Mode	wxSeekMode	wxFile.FromStart

Seeks the offset. Returns the actual position or -1. See also seekEnd.

seekEnd

seekEnd(Offset)
 

Name	Type	Default	Description
Offset	Integer		Offset to seek to.

Moves the file pointer to the specified number of bytes before the end of the file. Returns the actual position or -1 on error.

Remark: Is the same as calling seek(Offset, wxFile.FromEnd)

write

write(Buffer) : Integer
 

Name	Type	Default	Description
Buffer	wxMemoryBuffer

write(Str, 
      Encoding = UTF-8) : Integer
 

Name	Type	Default	Description
Str	String
Encoding	String	UTF-8

Writes the string or buffer to the file. A String is written in the specified encoding. The default is UTF-8 because most files are still written as UTF-8 or ASCII. Returns the actual number of bytes written to the file.