std::getchar

 

C++

Compiler support

Freestanding and hosted

Language

Standard library

Standard library headers

Named requirements

Feature test macros (C++20)

Language support library

Concepts library (C++20)

Diagnostics library

Memory management library

Metaprogramming library (C++11)

General utilities library

Containers library

Iterators library

Ranges library (C++20)

Algorithms library

Strings library

Text processing library

Numerics library

Date and time library

Input/output library

Filesystem library (C++17)

Concurrency support library (C++11)

Execution control library (C++26)

Technical specifications

Symbols index

External libraries

 

Input/output library

I/O manipulators

Print functions (C++23)

C-style I/O

Buffers

basic_streambuf

basic_filebuf

basic_stringbuf

basic_spanbuf (C++23)

strstreambuf (C++98/26*)

basic_syncbuf (C++20)

Streams

Abstractions

ios_base

basic_ios

basic_istream

basic_ostream

basic_iostream

File I/O

basic_ifstream

basic_ofstream

basic_fstream

String I/O

basic_istringstream

basic_ostringstream

basic_stringstream

Array I/O

basic_ispanstream (C++23)

basic_ospanstream (C++23)

basic_spanstream (C++23)

istrstream (C++98/26*)

ostrstream (C++98/26*)

strstream (C++98/26*)

Synchronized Output

basic_osyncstream (C++20)

Types

streamoff

streamsize

fpos

Error category interface

iostream_category (C++11)

io_errc (C++11)

 

C-style I/O

Types and objects
FILE fpos_t	stdinstdoutstderr
Functions
File access fopen freopen fclose fflush fwide setbuf setvbuf Direct input/output fread fwrite Unformatted input/output fgetcgetc fgets fputcputc fputs getchar gets (until C++14) putchar puts ungetc fgetwcgetwc fgetws fputwcputwc fputws getwchar putwchar ungetwc Formatted input scanffscanfsscanf vscanfvfscanfvsscanf (C++11)(C++11)(C++11)     wscanffwscanfswscanf vwscanfvfwscanfvswscanf (C++11)(C++11)(C++11)	Formatted output printffprintfsprintfsnprintf (C++11) vprintfvfprintfvsprintfvsnprintf (C++11)     wprintffwprintfswprintf vwprintfvfwprintfvswprintf File positioning ftell fgetpos fseek fsetpos rewind Error handling clearerr feof ferror perror Operations on files remove rename tmpfile tmpnam

 

Defined in header <cstdio>
int getchar();

Reads the next character from stdin.

Equivalent to std::getc(stdin).

Parameters

(none)

Return value

The obtained character on success or EOF on failure.

If the failure has been caused by end of file condition, additionally sets the eof indicator (see std::feof()) on stdin. If the failure has been caused by some other error, sets the error indicator (see std::ferror()) on stdin.

Example

std::getchar with error checking. Exit program by entering ESC char.

#include <cctype>
#include <cstdio>
#include <cstdlib>
#include <iomanip>
#include <iostream>
 
int main()
{
    for (int ch; (ch = std::getchar() != EOF ;) / read/print "abc" from stdin
    {
        if (std::isprint(ch))
            std::cout << static_cast<char>(ch) << '\n';
        if (ch == 27) / 'ESC' (escape) in ASCII
            return EXIT_SUCCESS;
    }
 
    / Test reason for reaching EOF.
    if (std::feof(stdin) / if failure caused by end-of-file condition
        std::cout << "End of file reached\n";
    else if (std::ferror(stdin) / if failure caused by some other error
    {
        std::perror("getchar()");
        std::cerr << "getchar() failed in file " << std::quoted(__FILE__)
                  << " at line # " << __LINE__ - 14 << '\n';
        std::exit(EXIT_FAILURE);
    }
 
    return EXIT_SUCCESS;
}

Possible output:

abc
a
b
c
^[

See also

fgetcgetc	gets a character from a file stream (function)
C documentation for getchar

Follow Lee on X/Twitter - Father, Husband, Serial builder creating AI, crypto, games & web tools. We are friends :) AI Will Come To Life!

Check out: eBank.nz (Art Generator) | Netwrck.com (AI Tools) | Text-Generator.io (AI API) | BitBank.nz (Crypto AI) | ReadingTime (Kids Reading) | RewordGame | BigMultiplayerChess | WebFiddle | How.nz | Helix AI Assistant