"""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 and the optional arguments mode and
openhook are ignored. 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 OSError
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.

XXX Possible additions:

- optional getopt argument processing
- isatty()
- read(), read(size), even readlines()

"""

import sys, os

__all__ = ["input", "close", "nextfile", "filename", "lineno", "filelineno",
 "fileno", "isfirstline", "isstdin", "FileInput", "hook_compressed",
 "hook_encoded"]

_state = None

def input(files=None, inplace=False, backup="", *, mode="r", openhook=None):
 """Return an instance of the FileInput class, which can be iterated.

 The parameters are passed to the constructor of the FileInput class.
 The returned instance, in addition to being an iterator,
 keeps global state for the functions of this module,.
 """
 global _state
 if _state and _state._file:
 raise RuntimeError("input() already active")
 _state = FileInput(files, inplace, backup, mode=mode, openhook=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:
 """FileInput([files[, inplace[, backup]]], *, mode=None, openhook=None)

 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=False, backup="", *,
 mode="r", openhook=None):
 if isinstance(files, str):
 files = (files,)
 elif isinstance(files, os.PathLike):
 files = (os.fspath(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._savestdout = None
 self._output = None
 self._filename = None
 self._startlineno = 0
 self._filelineno = 0
 self._file = None
 self._isstdin = False
 self._backupfilename = None
 # 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'")
 if 'U' in mode:
 import warnings
 warnings.warn("'U' mode is deprecated",
 DeprecationWarning, 2)
 self._mode = mode
 self._write_mode = mode.replace('r', 'w') if 'U' not in mode else 'w'
 if openhook:
 if inplace:
 raise ValueError("FileInput cannot use an opening hook in inplace mode")
 if not callable(openhook):
 raise ValueError("FileInput openhook must be callable")
 self._openhook = openhook

 def __del__(self):
 self.close()

 def close(self):
 try:
 self.nextfile()
 finally:
 self._files = ()

 def __enter__(self):
 return self

 def __exit__(self, type, value, traceback):
 self.close()

 def __iter__(self):
 return self

 def __next__(self):
 while True:
 line = self._readline()
 if line:
 self._filelineno += 1
 return line
 if not self._file:
 raise StopIteration
 self.nextfile()
 # repeat with next file

 def __getitem__(self, i):
 import warnings
 warnings.warn(
 "Support for indexing FileInput objects is deprecated. "
 "Use iterator protocol instead.",
 DeprecationWarning,
 stacklevel=2
 )
 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 = None
 if savestdout:
 sys.stdout = savestdout

 output = self._output
 self._output = None
 try:
 if output:
 output.close()
 finally:
 file = self._file
 self._file = None
 try:
 del self._readline # restore FileInput._readline
 except AttributeError:
 pass
 try:
 if file and not self._isstdin:
 file.close()
 finally:
 backupfilename = self._backupfilename
 self._backupfilename = None
 if backupfilename and not self._backup:
 try: os.unlink(backupfilename)
 except OSError: pass

 self._isstdin = False

 def readline(self):
 while True:
 line = self._readline()
 if line:
 self._filelineno += 1
 return line
 if not self._file:
 return line
 self.nextfile()
 # repeat with next file

 def _readline(self):
 if not self._files:
 if 'b' in self._mode:
 return b''
 else:
 return ''
 self._filename = self._files[0]
 self._files = self._files[1:]
 self._startlineno = self.lineno()
 self._filelineno = 0
 self._file = None
 self._isstdin = False
 self._backupfilename = 0
 if self._filename == '-':
 self._filename = '<stdin>'
 if 'b' in self._mode:
 self._file = getattr(sys.stdin, 'buffer', sys.stdin)
 else:
 self._file = sys.stdin
 self._isstdin = True
 else:
 if self._inplace:
 self._backupfilename = (
 os.fspath(self._filename) + (self._backup or ".bak"))
 try:
 os.unlink(self._backupfilename)
 except OSError:
 pass
 # The next few lines may raise OSError
 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, self._write_mode)
 else:
 mode = os.O_CREAT | os.O_WRONLY | os.O_TRUNC
 if hasattr(os, 'O_BINARY'):
 mode |= os.O_BINARY

 fd = os.open(self._filename, mode, perm)
 self._output = os.fdopen(fd, self._write_mode)
 try:
 os.chmod(self._filename, perm)
 except OSError:
 pass
 self._savestdout = sys.stdout
 sys.stdout = self._output
 else:
 # This may raise OSError
 if self._openhook:
 self._file = self._openhook(self._filename, self._mode)
 else:
 self._file = open(self._filename, self._mode)
 self._readline = self._file.readline # hide FileInput._readline
 return self._readline()

 def filename(self):
 return self._filename

 def lineno(self):
 return self._startlineno + self._filelineno

 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, errors=None):
 def openhook(filename, mode):
 return open(filename, mode, encoding=encoding, errors=errors)
 return openhook


def _test():
 import getopt
 inplace = False
 backup = False
 opts, args = getopt.getopt(sys.argv[1:], "ib:")
 for o, a in opts:
 if o == '-i': inplace = True
 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()