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C-style file input/output

From cppreference.com
< cpp‎ | io
 
 
Input/output library
I/O manipulators
C-style I/O
Buffers
(deprecated in C++98)
Streams
Abstractions
File I/O
String I/O
Array I/O
(deprecated in C++98)
(deprecated in C++98)
(deprecated in C++98)
Synchronized Output
Types
Error category interface
(C++11)
 
C-style I/O
 

The C I/O subset of the C++ standard library implements C-style stream input/output operations. The <cstdio> header provides generic file operation support and supplies functions with narrow and multibyte character input/output capabilities, and the <cwchar> header provides functions with wide character input/output capabilities.

C streams are denoted by objects of type std::FILE that can only be accessed and manipulated through pointers of type std::FILE*. Each C stream is associated with an external physical device (file, standard input stream, printer, serial port, etc).

Contents

[edit] Types

Defined in header <cstdio>
object type, capable of holding all information needed to control a C I/O stream
(typedef) [edit]
complete non-array object type, capable of uniquely specifying a position in a file, including its multibyte parse state
(typedef) [edit]

[edit] Predefined standard streams

Defined in header <cstdio>
expression of type FILE* associated with the input stream
expression of type FILE* associated with the output stream
expression of type FILE* associated with the error output stream
(macro constant) [edit]

[edit] Functions

Defined in header <cstdio>
File access
opens a file
(function) [edit]
open an existing stream with a different name
(function) [edit]
closes a file
(function) [edit]
synchronizes an output stream with the actual file
(function) [edit]
switches a file stream between wide character I/O and narrow character I/O
(function) [edit]
sets the buffer for a file stream
(function) [edit]
sets the buffer and its size for a file stream
(function) [edit]
Direct input/output
reads from a file
(function) [edit]
writes to a file
(function) [edit]
Unformatted input/output
Byte/multibyte character
gets a character from a file stream
(function) [edit]
gets a character string from a file stream
(function) [edit]
writes a character to a file stream
(function) [edit]
writes a character string to a file stream
(function) [edit]
reads a character from stdin
(function) [edit]
(deprecated in C++11)(removed in C++14)
reads a character string from stdin
(function) [edit]
writes a character to stdout
(function) [edit]
writes a character string to stdout
(function) [edit]
puts a character back into a file stream
(function) [edit]
Wide character
gets a wide character from a file stream
(function) [edit]
gets a wide string from a file stream
(function) [edit]
writes a wide character to a file stream
(function) [edit]
writes a wide string to a file stream
(function) [edit]
reads a wide character from stdin
(function) [edit]
writes a wide character to stdout
(function) [edit]
puts a wide character back into a file stream
(function) [edit]
Formatted input/output
Byte/multibyte character
reads formatted input from stdin, a file stream or a buffer
(function) [edit]
(C++11)(C++11)(C++11)
reads formatted input from stdin, a file stream or a buffer
using variable argument list
(function) [edit]
prints formatted output to stdout, a file stream or a buffer
(function) [edit]
prints formatted output to stdout, a file stream or a buffer
using variable argument list
(function) [edit]
Wide character
reads formatted wide character input from stdin, a file stream or a buffer
(function) [edit]
(C++11)(C++11)(C++11)
reads formatted wide character input from stdin, a file stream
or a buffer using variable argument list
(function) [edit]
prints formatted wide character output to stdout, a file stream or a buffer
(function) [edit]
prints formatted wide character output to stdout, a file stream
or a buffer using variable argument list
(function) [edit]
File positioning
returns the current file position indicator
(function) [edit]
gets the file position indicator
(function) [edit]
moves the file position indicator to a specific location in a file
(function) [edit]
moves the file position indicator to a specific location in a file
(function) [edit]
moves the file position indicator to the beginning in a file
(function) [edit]
Error handling
clears errors
(function) [edit]
checks for the end-of-file
(function) [edit]
checks for a file error
(function) [edit]
displays a character string corresponding of the current error to stderr
(function) [edit]
Operations on files
erases a file
(function) [edit]
renames a file
(function) [edit]
creates and opens a temporary, auto-removing file
(function) [edit]
returns a unique filename
(function) [edit]

[edit] Macro constants

Defined in header <cstdio>
EOF
integer constant expression of type int and negative value
(macro constant)
FOPEN_MAX
number of files that can be open simultaneously
(macro constant)
FILENAME_MAX
size needed for an array of char to hold the longest supported file name
(macro constant)
BUFSIZ
size of the buffer used by std::setbuf
(macro constant)
_IOFBF_IOLBF_IONBF
argument to std::setbuf indicating fully buffered I/O
argument to std::setbuf indicating line buffered I/O
argument to std::setbuf indicating unbuffered I/O
(macro constant)
SEEK_SETSEEK_CURSEEK_END
argument to std::fseek indicating seeking from beginning of the file
argument to std::fseek indicating seeking from the current file position
argument to std::fseek indicating seeking from end of the file
(macro constant)
TMP_MAX
maximum number of unique filenames that can be generated by std::tmpnam
(macro constant)
L_tmpnam
size needed for an array of char to hold the result of std::tmpnam
(macro constant)

[edit] See also

C documentation for File input/output