C++ reference: ifstream

basic_ifstream
ifstream
wifstream
File input stream class

iostream library

cplusplus.com

Public member functions:

ifstream members:

(constructor) Construct an object and optionally open a file.

rdbuf Get the filebuf object associated with the stream.

is_open Check if a file has been opened.

open Open a file.

close Close an open file.

members inherited from istream:

operator>> Perform formatted input operation (extraction)

gcount Get number of characters extracted by last unformatted input operation

get Extract unformatted data from stream

getline Get a line from stream

ignore Extract and discard characters

peek Peek next character

putback Put the last character back to stream

read Read a block of data

readsome Read a block of data

seekg Set position of the get pointer

sync Syncronize stream's buffer with source of characters

tellg Get position of the get pointer

unget Make last character got from stream available again

members inherited from ios:

operator void * Convert stream to pointer.

operator ! Evaluate stream object.

bad Check if an unrecoverable error has occurred.

clear Set control states.

copyfmt Copy formatting information.

eof Check if End-Of-File has been reached.

exceptions Get/set the exception mask.

fail Check if failure has occurred.

fill Get/set the fill character.

good Check if stream is good for i/o operations.

imbue Imbue locale.

narrow Narrow character.

rdbuf Get/set the associated streambuf object.

rdstate Get control state.

setstate Set control state.

tie Get/set the tied stream.

widen Widen character.

members inherited from ios_base:

flags Get/set format flags.

getloc Get current locale.

imbue Imbue locale.

iword Get reference to a long element of the internal extensible array.

precision Get/set floating-point decimal presision.

pword Get reference to a void* element of the internal extensible array.

register_callback Register event callback function.

setf Set some format flags.

sync_with_stdio Activates / Deactivates synchronization with cstdio functions. [static]

unsetf Clear format flag.

width Get/set field width.

xalloc Return a new index for the internal extensible array. [static]

ifstream class provides a stream interface to read data from files.
The class mantains internally (privately) a pointer to a filebuf object in charge of the interaction with the file. This pointer can be obtained/modified by calling member rdbuf.
The file to be processed can be specified as a parameter for the constructor or by calling member open.
After a file is processed it can be closed by calling member close. In this case the file stream may be used to open another file.
Member is_open can be used to determine wether the stream is currently operating on a file or not.
Please refer to parent classes for more details on information mantained by an ifstream object.

Standard hierarchy

Public member functions:

Description

ifstream members:
(constructor)	Construct an object and optionally open a file.
rdbuf	Get the filebuf object associated with the stream.
is_open	Check if a file has been opened.
open	Open a file.
close	Close an open file.
members inherited from istream:
operator>>	Perform formatted input operation (extraction)
gcount	Get number of characters extracted by last unformatted input operation
get	Extract unformatted data from stream
getline	Get a line from stream
ignore	Extract and discard characters
peek	Peek next character
putback	Put the last character back to stream
read	Read a block of data
readsome	Read a block of data
seekg	Set position of the get pointer
sync	Syncronize stream's buffer with source of characters
tellg	Get position of the get pointer
unget	Make last character got from stream available again
members inherited from ios:
operator void *	Convert stream to pointer.
operator !	Evaluate stream object.
bad	Check if an unrecoverable error has occurred.
clear	Set control states.
copyfmt	Copy formatting information.
eof	Check if End-Of-File has been reached.
exceptions	Get/set the exception mask.
fail	Check if failure has occurred.
fill	Get/set the fill character.
good	Check if stream is good for i/o operations.
imbue	Imbue locale.
narrow	Narrow character.
rdbuf	Get/set the associated streambuf object.
rdstate	Get control state.
setstate	Set control state.
tie	Get/set the tied stream.
widen	Widen character.
members inherited from ios_base:
flags	Get/set format flags.
getloc	Get current locale.
imbue	Imbue locale.
iword	Get reference to a long element of the internal extensible array.
precision	Get/set floating-point decimal presision.
pword	Get reference to a void* element of the internal extensible array.
register_callback	Register event callback function.
setf	Set some format flags.
sync_with_stdio	Activates / Deactivates synchronization with cstdio functions. [static]
unsetf	Clear format flag.
width	Get/set field width.
xalloc	Return a new index for the internal extensible array. [static]