be used to control how files are opened.

specifying the file mode input files should be opened with.

current file number.

see bug 411881

equivalent attributes in a few more spots.

This closes SF patch http://www.python.org/sf/562373

Closes patch 556161.

other ways of reading input. :-(

In the process, I added an optional bufsize argument to the input()
function and the FileInput class.

default list of files from () to None, and explicitly test for None
before defaulting to sys.argv[1:].  This means that if you pass in an
explicit empty list, it will read stdin instead of defaulting to
sys.argv[1:].  This fixes a buglet in the test script (when called
with options but without files, it chokes when it tries to interpret
the options as files).

Lawrence adds: "I suspect that this is a safe change, because I can't
imagine someone actively passing in an empty list when they want
sys.argv used."

I agree.

same permissions as the old file, plugging a security hole.
(Not using exactly the suggested bugfix.)

the writing of filters.

Typical use is:

    import fileinput
    for line in fileinput.input():
        process(line)

This iterates over the lines of all files listed in sys.argv[1:],
defaulting to sys.stdin if the list is empty or when a filename is
'-'.

There is also an option to use this to direct the output back to the
input files.