nsIFileInputStream

An input stream that allows you to read from a file.
Inherits from: nsIInputStream Last changed in Gecko 1.7

Method overview

void init(in nsIFile file, in long ioFlags, in long perm, in long behaviorFlags);

Constants

Constant Value Description
DELETE_ON_CLOSE 1<<1 If this is set, the file will be deleted by the time the stream is closed. It may be removed before the stream is closed if it is possible to delete it and still read from it. If OPEN_ON_READ is defined, and the file was recreated after the first delete, the file will be deleted again when it is closed again.
CLOSE_ON_EOF 1<<2 If this is set, the file will close automatically when the end of the file is reached.
REOPEN_ON_REWIND 1<<3 If this is set, the file will be reopened whenever Seek(0) occurs. If the file is already open and the seek occurs, it will happen naturally. (The file will only be reopened if it is closed for some reason.)
DEFER_OPEN 1<<4 If this is set, the file will be opened (i.e., a call to PR_Open() done) only when we do an actual operation on the stream, or more specifically, when one of the following is called:
  • Seek()
  • Tell()
  • Available()
  • Read()
  • ReadLine()

DEFER_OPEN is useful if we use the stream on a background thread, so that the opening and possible stating of the file happens there as well.

Note: Using this flag results in the file not being opened during the call to init. This means that any errors that might happen when this flag is not set would happen during the first read. Also, the file is not locked when init is called, so it might be deleted before we try to read from it.

Methods

init()

void init(
  in nsIFile file,
  in long ioFlags,
  in long perm,
  in long behaviorFlags
);
Parameters
file
File to read from (must QI to nsILocalFile)
ioFlags
The file status flags define how the file is accessed. See PR_Open documentation for more details. If set to -1 the file will be opened in default mode (PR_RDONLY).
perm
File mode bits are described in the PR_Open documentation. If set to -1 the default value 0 will be used.
behaviorFlags
Flags specifying various behaviors of the class (see enumerations in the class).

See also

Document Tags and Contributors

Contributors to this page: vandy, Sheppy, philikon, simonster, trevorh, Smi, Ayhfung
Last updated by: vandy,