"""Helper class to quickly write a loop over all standard input files.

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.  If a filename is '-' it

is also replaced by sys.stdin.  To specify an alternative list of

filenames, pass it as the argument to input().  A single file name is

also allowed.

Functions filename(), lineno() return the filename and cumulative line

number of the line that has just been read; filelineno() returns its

line number in the current file; isfirstline() returns true iff the

line just read is the first line of its file; isstdin() returns true

iff the line was read from sys.stdin.  Function nextfile() closes the

current file so that the next iteration will read the first line from

the next file (if any); lines not read from the file will not count

towards the cumulative line count; the filename is not changed until

after the first line of the next file has been read.  Function close()

closes the sequence.

Before any lines have been read, filename() returns None and both line

numbers are zero; nextfile() has no effect.  After all lines have been

read, filename() and the line number functions return the values

pertaining to the last line read; nextfile() has no effect.

All files are opened in text mode by default, you can override this by

setting the mode parameter to input() or FileInput.__init__().

If an I/O error occurs during opening or reading a file, the IOError

exception is raised.

If sys.stdin is used more than once, the second and further use will

return no lines, except perhaps for interactive use, or if it has been

explicitly reset (e.g. using sys.stdin.seek(0)).

Empty files are opened and immediately closed; the only time their

presence in the list of filenames is noticeable at all is when the

last file opened is empty.

It is possible that the last line of a file doesn't end in a newline

character; otherwise lines are returned including the trailing

newline.

Class FileInput is the implementation; its methods filename(),

lineno(), fileline(), isfirstline(), isstdin(), nextfile() and close()

correspond to the functions in the module.  In addition it has a

readline() method which returns the next input line, and a

__getitem__() method which implements the sequence behavior.  The

sequence must be accessed in strictly sequential order; sequence

access and readline() cannot be mixed.

Optional in-place filtering: if the keyword argument inplace=1 is

passed to input() or to the FileInput constructor, the file is moved

to a backup file and standard output is directed to the input file.

This makes it possible to write a filter that rewrites its input file

in place.  If the keyword argument backup=".<some extension>" is also

given, it specifies the extension for the backup file, and the backup

file remains around; by default, the extension is ".bak" and it is

deleted when the output file is closed.  In-place filtering is

disabled when standard input is read.  XXX The current implementation

does not work for MS-DOS 8+3 filesystems.

Performance: this module is unfortunately one of the slower ways of

processing large numbers of input lines.  Nevertheless, a significant

speed-up has been obtained by using readlines(bufsize) instead of

readline().  A new keyword argument, bufsize=N, is present on the

input() function and the FileInput() class to override the default

buffer size.

XXX Possible additions:

- optional getopt argument processing

- isatty()

- read(), read(size), even readlines()

"""

import sys, os

__all__ = ["input","close","nextfile","filename","lineno","filelineno",

           "isfirstline","isstdin","FileInput"]

_state = None

DEFAULT_BUFSIZE = 8*1024

def input(files=None, inplace=0, backup="", bufsize=0,

          mode="r", openhook=None):

    """input([files[, inplace[, backup[, mode[, openhook]]]]])

    Create an instance of the FileInput class. The instance will be used

    as global state for the functions of this module, and is also returned

    to use during iteration. The parameters to this function will be passed

    along to the constructor of the FileInput class.

    """

    global _state

    if _state and _state._file:

        raise RuntimeError, "input() already active"

    _state = FileInput(files, inplace, backup, bufsize, mode, openhook)

    return _state

def close():

    """Close the sequence."""

    global _state

    state = _state

    _state = None

    if state:

        state.close()

def nextfile():

    """

    Close the current file so that the next iteration will read the first

    line from the next file (if any); lines not read from the file will

    not count towards the cumulative line count. The filename is not

    changed until after the first line of the next file has been read.

    Before the first line has been read, this function has no effect;

    it cannot be used to skip the first file. After the last line of the

    last file has been read, this function has no effect.

    """

    if not _state:

        raise RuntimeError, "no active input()"

    return _state.nextfile()

def filename():

    """

    Return the name of the file currently being read.

    Before the first line has been read, returns None.

    """

    if not _state:

        raise RuntimeError, "no active input()"

    return _state.filename()

def lineno():

    """

    Return the cumulative line number of the line that has just been read.

    Before the first line has been read, returns 0. After the last line

    of the last file has been read, returns the line number of that line.

    """

    if not _state:

        raise RuntimeError, "no active input()"

    return _state.lineno()

def filelineno():

    """

    Return the line number in the current file. Before the first line

    has been read, returns 0. After the last line of the last file has

    been read, returns the line number of that line within the file.

    """

    if not _state:

        raise RuntimeError, "no active input()"

    return _state.filelineno()

def fileno():

    """

    Return the file number of the current file. When no file is currently

    opened, returns -1.

    """

    if not _state:

        raise RuntimeError, "no active input()"

    return _state.fileno()

def isfirstline():

    """

    Returns true the line just read is the first line of its file,

    otherwise returns false.

    """

    if not _state:

        raise RuntimeError, "no active input()"

    return _state.isfirstline()

def isstdin():

    """

    Returns true if the last line was read from sys.stdin,

    otherwise returns false.

    """

    if not _state:

        raise RuntimeError, "no active input()"

    return _state.isstdin()

class FileInput:

    """class FileInput([files[, inplace[, backup[, mode[, openhook]]]]])

    Class FileInput is the implementation of the module; its methods

    filename(), lineno(), fileline(), isfirstline(), isstdin(), fileno(),

    nextfile() and close() correspond to the functions of the same name

    in the module.

    In addition it has a readline() method which returns the next

    input line, and a __getitem__() method which implements the

    sequence behavior. The sequence must be accessed in strictly

    sequential order; random access and readline() cannot be mixed.

    """

    def __init__(self, files=None, inplace=0, backup="", bufsize=0,

                 mode="r", openhook=None):

        if isinstance(files, basestring):

            files = (files,)

        else:

            if files is None:

                files = sys.argv[1:]

            if not files:

                files = ('-',)

            else:

                files = tuple(files)

        self._files = files

        self._inplace = inplace

        self._backup = backup

        self._bufsize = bufsize or DEFAULT_BUFSIZE

        self._savestdout = None

        self._output = None

        self._filename = None

        self._lineno = 0

        self._filelineno = 0

        self._file = None

        self._isstdin = False

        self._backupfilename = None

        self._buffer = []

        self._bufindex = 0

        # restrict mode argument to reading modes

        if mode not in ('r', 'rU', 'U', 'rb'):

            raise ValueError("FileInput opening mode must be one of "

                             "'r', 'rU', 'U' and 'rb'")

        self._mode = mode

        if inplace and openhook:

            raise ValueError("FileInput cannot use an opening hook in inplace mode")

        elif openhook and not hasattr(openhook, '__call__'):

            raise ValueError("FileInput openhook must be callable")

        self._openhook = openhook

    def __del__(self):

        self.close()

    def close(self):

        self.nextfile()

        self._files = ()

    def __iter__(self):

        return self

    def next(self):

        try:

            line = self._buffer[self._bufindex]

        except IndexError:

            pass

        else:

            self._bufindex += 1

            self._lineno += 1

            self._filelineno += 1

            return line

        line = self.readline()

        if not line:

            raise StopIteration

        return line

    def __getitem__(self, i):

        if i != self._lineno:

            raise RuntimeError, "accessing lines out of order"

        try:

            return self.next()

        except StopIteration:

            raise IndexError, "end of input reached"

    def nextfile(self):

        savestdout = self._savestdout

        self._savestdout = 0

        if savestdout:

            sys.stdout = savestdout

        output = self._output

        self._output = 0

        if output:

            output.close()

        file = self._file

        self._file = 0

        if file and not self._isstdin:

            file.close()

        backupfilename = self._backupfilename

        self._backupfilename = 0

        if backupfilename and not self._backup:

            try: os.unlink(backupfilename)

            except OSError: pass

        self._isstdin = False

        self._buffer = []

        self._bufindex = 0

    def readline(self):

        try:

            line = self._buffer[self._bufindex]

        except IndexError:

            pass

        else:

            self._bufindex += 1

            self._lineno += 1

            self._filelineno += 1

            return line

        if not self._file:

            if not self._files:

                return ""

            self._filename = self._files[0]

            self._files = self._files[1:]

            self._filelineno = 0

            self._file = None

            self._isstdin = False

            self._backupfilename = 0

            if self._filename == '-':

                self._filename = '<stdin>'

                self._file = sys.stdin

                self._isstdin = True

            else:

                if self._inplace:

                    self._backupfilename = (

                        self._filename + (self._backup or os.extsep+"bak"))

                    try: os.unlink(self._backupfilename)

                    except os.error: pass

                    # The next few lines may raise IOError

                    os.rename(self._filename, self._backupfilename)

                    self._file = open(self._backupfilename, self._mode)

                    try:

                        perm = os.fstat(self._file.fileno()).st_mode

                    except OSError:

                        self._output = open(self._filename, "w")

                    else:

                        fd = os.open(self._filename,

                                     os.O_CREAT | os.O_WRONLY | os.O_TRUNC,

                                     perm)

                        self._output = os.fdopen(fd, "w")

                        try:

                            if hasattr(os, 'chmod'):

                                os.chmod(self._filename, perm)

                        except OSError:

                            pass

                    self._savestdout = sys.stdout

                    sys.stdout = self._output

                else:

                    # This may raise IOError

                    if self._openhook:

                        self._file = self._openhook(self._filename, self._mode)

                    else:

                        self._file = open(self._filename, self._mode)

        self._buffer = self._file.readlines(self._bufsize)

        self._bufindex = 0

        if not self._buffer:

            self.nextfile()

        # Recursive call

        return self.readline()

    def filename(self):

        return self._filename

    def lineno(self):

        return self._lineno

    def filelineno(self):

        return self._filelineno

    def fileno(self):

        if self._file:

            try:

                return self._file.fileno()

            except ValueError:

                return -1

        else:

            return -1

    def isfirstline(self):

        return self._filelineno == 1

    def isstdin(self):

        return self._isstdin

def hook_compressed(filename, mode):

    ext = os.path.splitext(filename)[1]

    if ext == '.gz':

        import gzip

        return gzip.open(filename, mode)

    elif ext == '.bz2':

        import bz2

        return bz2.BZ2File(filename, mode)

    else:

        return open(filename, mode)

def hook_encoded(encoding):

    import codecs

    def openhook(filename, mode):

        return codecs.open(filename, mode, encoding)

    return openhook

def _test():

    import getopt

    inplace = 0

    backup = 0

    opts, args = getopt.getopt(sys.argv[1:], "ib:")

    for o, a in opts:

        if o == '-i': inplace = 1

        if o == '-b': backup = a

    for line in input(args, inplace=inplace, backup=backup):

        if line[-1:] == '\n': line = line[:-1]

        if line[-1:] == '\r': line = line[:-1]

        print "%d: %s[%d]%s %s" % (lineno(), filename(), filelineno(),

                                   isfirstline() and "*" or "", line)

    print "%d: %s[%d]" % (lineno(), filename(), filelineno())

if __name__ == '__main__':

    _test()