#ifndef REGTEST
+int ungetc_unlocked( int c, struct _PDCLIB_file_t * stream )
+{
+ if ( c == EOF || stream->ungetidx == _PDCLIB_UNGETCBUFSIZE )
+ {
+ return -1;
+ }
+ return stream->ungetbuf[stream->ungetidx++] = (unsigned char) c;
+}
+
int ungetc( int c, struct _PDCLIB_file_t * stream )
{
- /* TODO: Implement. */
- return 0;
+ flockfile( stream );
+ int r = ungetc_unlocked( c, stream );
+ funlockfile( stream);
+ return r;
}
#endif
#ifdef TEST
#include <_PDCLIB_test.h>
+#include <stdlib.h>
+
+const char* hellostr = "Hello, world!";
int main( void )
{
- TESTCASE( NO_TESTDRIVER );
+ // 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;
}