fgetc()

Arguments:

fp

The stream from which you want to read a character.

Library:

libc

Use the -l c option to qcc to link against this library. This library is usually included automatically.

Description:

The fgetc() function reads the next character from the stream specified by fp.

Returns:

• If successful, fgetc() returns the next character from fp, cast as (int)(unsigned char).
• If the end-of-file indicator for the stream is set or the end of the file has been reached, fgetc() sets the end-of-file indicator and returns EOF.
• If an error occurred, fgetc() sets the error indicator for the stream, sets errno, and returns EOF.

Errors:

EAGAIN

The O_NONBLOCK flag is set for the file descriptor underlying fp, and the process would be delayed in the write operation.

EBADF

The file descriptor underlying fp isn't a valid file descriptor that's open for reading.

EINTR

The read operation was terminated due to the receipt of a signal, and no data was transferred.

EIO

One of the following:

• A physical I/O error occurred.
• The process is in a background process group attempting to read from its controlling terminal, and either the process is ignoring or blocking the SIGTTIN signal or the process group is orphaned.
• (QNX OS extension) The filesystem resides on a removable media device, and the media has been forcibly removed.

ENOMEM

Insufficient space is available.

ENXIO

A request was made of a nonexistent device, or the request was outside the capabilities of the device.

EOVERFLOW

The file is a regular file, and an attempt was made to read at or beyond the offset maximum associated with the corresponding stream.

Examples:

#include <stdio.h>
#include <stdlib.h>

int main( void ) 
{
    FILE *fp;
    int c;

    fp = fopen( "file", "r" );
    if( fp != NULL ) {
        while( (c = fgetc( fp )) != EOF ) {
            fputc( c, stdout );
        }
        fclose( fp );
        
        return EXIT_SUCCESS;
    }
    
    return EXIT_FAILURE;
}

Classification:

ANSI, POSIX 1003.1