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/* IBM_PROLOG_BEGIN_TAG */
/* This is an automatically generated prolog. */
/* */
/* $Source: src/lib/ppc405lib/fgetc.c $ */
/* */
/* OpenPOWER OnChipController Project */
/* */
/* Contributors Listed Below - COPYRIGHT 2015,2016 */
/* [+] International Business Machines Corp. */
/* */
/* */
/* Licensed under the Apache License, Version 2.0 (the "License"); */
/* you may not use this file except in compliance with the License. */
/* You may obtain a copy of the License at */
/* */
/* http://www.apache.org/licenses/LICENSE-2.0 */
/* */
/* Unless required by applicable law or agreed to in writing, software */
/* distributed under the License is distributed on an "AS IS" BASIS, */
/* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or */
/* implied. See the License for the specific language governing */
/* permissions and limitations under the License. */
/* */
/* IBM_PROLOG_END_TAG */
/// \file fgetc.c
/// \brief Implementation of fgetc() and ungetc()
///
/// The implementations of these APIs are split out to save code space for
/// applications that do not require them.
#include "ssx_io.h"
/// Read a character from a stream
///
/// fgetc() reads the next character from \a stream and returns it as an
/// unsigned char cast to an int, or EOF on end of file or error.
int
fgetc(FILE* stream)
{
unsigned char c;
size_t read;
int rc;
if (stream->flags & SSX_FILE_HAS_CHARACTER) {
stream->flags &= ~SSX_FILE_HAS_CHARACTER;
rc = stream->character;
} else {
rc = sread(stream, &c, 1, &read);
if (rc || (read != 1)) {
rc = EOF;
} else {
rc = c;
if (c == '\n') {
stream->lines++;
}
}
}
return rc;
}
/// Push a character back onto a stream
///
/// ungetc() pushes \a c back to \a stream, cast to unsigned char, where it is
/// available for subsequent fgetc() operations. Only one pushback is
/// implemented. A call of ungetc() on a stream that already has a character
/// pushed back will drop the new push-back and return EOF. Otherwise
/// ungetc() returns \a c.
int
ungetc(int c, FILE* stream)
{
int rc;
if (stream->flags & SSX_FILE_HAS_CHARACTER) {
rc = EOF;
} else {
stream->flags |= SSX_FILE_HAS_CHARACTER;
stream->character = c;
rc = c;
}
return rc;
}
/// Return the number of newline characters read from a stream
///
/// This API is an SSX entension to the \<stdio\> APIs. It returns the number
/// of newline characters read from the stream using fgetc(). Newline
/// characters read via direct calls to sread() in the stream are not counted.
///
/// An application that sees an error while reading from a stream can print
/// flines() or flines() + 1 (depending on the application) to help users
/// track down errors in their input.
size_t
flines(FILE* stream)
{
return stream->lines;
}
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