Implementation status: partially implemented


#include <stdio.h>

int fgetc(FILE *stream);


The function gets the next character (an unsigned char) from the specified stream and advances the position indicator for the stream.

stream - the input stream.

If the end-of-file indicator for the input stream pointed to by stream is not set and a next byte is present, the fgetc() function obtains the next byte as an unsigned char converted to an int, from the input stream pointed to by stream, and advances the associated file position indicator for the stream (if defined). Since fgetc() operates on bytes, reading a character consisting of multiple bytes (or "a multi-byte character") requires multiple calls to fgetc().

Return value

Upon successful completion, fgetc() returns the next byte from the input stream pointed to by stream.

If the end-of-file indicator for the stream is set, or if the stream is at end-of-file, the end-of-file indicator for the stream is set and fgetc() returns EOF. If a read error occurs, the error indicator for the stream is set, fgetc() returns EOF, and sets errno to indicate the error.


[EAGAIN] The O_NONBLOCK flag is set for the file descriptor underlying stream and the thread would be delayed in the fgetc() operation.
[EBADF] The file descriptor underlying stream is not a valid file descriptor open for reading.
[EINTR] The read operation was terminated due to the receipt of a signal, and no data was transferred.
[EIO] A physical I/O error has occurred, or the process is in a background process group attempting to read from its controlling terminal, and either the calling thread is blocking SIGTTIN or the process is ignoring SIGTTIN or the process group of the process is orphaned.
[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.
[ENOMEM] Insufficient storage space is available.
[ENXIO] A request was made of a nonexistent device, or the request was outside the capabilities of the device.

Implementation tasks

  • Implement error handling for the function.