BizHawk/waterbox/libc/functions/stdio/ungetc.c

68 lines
1.4 KiB
C

/* ungetc( int, FILE * )
This file is part of the Public Domain C Library (PDCLib).
Permission is granted to use, modify, and / or redistribute at will.
*/
#include <stdio.h>
#ifndef REGTEST
#include "_PDCLIB_io.h"
int _PDCLIB_ungetc_unlocked( int c, FILE * stream )
{
if ( c == EOF || stream->ungetidx == _PDCLIB_UNGETCBUFSIZE )
{
return -1;
}
return stream->ungetbuf[stream->ungetidx++] = (unsigned char) c;
}
int ungetc( int c, FILE * stream )
{
_PDCLIB_flockfile( stream );
int r = _PDCLIB_ungetc_unlocked( c, stream );
_PDCLIB_funlockfile( stream);
return r;
}
#endif
#ifdef TEST
#include "_PDCLIB_test.h"
#include <stdlib.h>
const char* hellostr = "Hello, world!";
int main( void )
{
// Also see ftell() for some testing
// PDCLIB-18: fread ignores ungetc
size_t bufsz = strlen( hellostr ) + 1;
char * buf = malloc( bufsz );
FILE * fh;
// Also fgets
TESTCASE( ( fh = tmpfile() ) != NULL );
TESTCASE( fputs(hellostr, fh) == 0 );
rewind(fh);
TESTCASE( fgetc( fh ) == 'H' );
TESTCASE( ungetc( 'H', fh ) == 'H' );
TESTCASE( fgets( buf, bufsz, fh ) != NULL );
TESTCASE( strcmp( buf, hellostr ) == 0 );
// fread
rewind(fh);
TESTCASE( fgetc( fh ) == 'H' );
TESTCASE( ungetc( 'H', fh ) == 'H' );
TESTCASE( fread( buf, bufsz - 1, 1, fh ) == 1 );
TESTCASE( strncmp( buf, hellostr, bufsz - 1 ) == 0 );
return TEST_RESULTS;
}
#endif