diff options
Diffstat (limited to 'newlib/libc/stdio/refill.c')
-rw-r--r-- | newlib/libc/stdio/refill.c | 113 |
1 files changed, 113 insertions, 0 deletions
diff --git a/newlib/libc/stdio/refill.c b/newlib/libc/stdio/refill.c new file mode 100644 index 0000000..bc3b830 --- /dev/null +++ b/newlib/libc/stdio/refill.c @@ -0,0 +1,113 @@ +/* No user fns here. Pesch 15apr92. */ + +/* + * Copyright (c) 1990 The Regents of the University of California. + * All rights reserved. + * + * Redistribution and use in source and binary forms are permitted + * provided that the above copyright notice and this paragraph are + * duplicated in all such forms and that any documentation, + * advertising materials, and other materials related to such + * distribution and use acknowledge that the software was developed + * by the University of California, Berkeley. The name of the + * University may not be used to endorse or promote products derived + * from this software without specific prior written permission. + * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR + * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED + * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. + */ + +#include <stdio.h> +#include "local.h" +#include <stdlib.h> + +static int +lflush (fp) + FILE *fp; +{ + if ((fp->_flags & (__SLBF | __SWR)) == __SLBF | __SWR) + return fflush (fp); + return 0; +} + +/* + * Refill a stdio buffer. + * Return EOF on eof or error, 0 otherwise. + */ + +int +_DEFUN (__srefill, (fp), + register FILE * fp) +{ + /* make sure stdio is set up */ + + CHECK_INIT (fp); + + fp->_r = 0; /* largely a convenience for callers */ + + /* SysV does not make this test; take it out for compatibility */ + if (fp->_flags & __SEOF) + return EOF; + + /* if not already reading, have to be reading and writing */ + if ((fp->_flags & __SRD) == 0) + { + if ((fp->_flags & __SRW) == 0) + return EOF; + /* switch to reading */ + if (fp->_flags & __SWR) + { + if (fflush (fp)) + return EOF; + fp->_flags &= ~__SWR; + fp->_w = 0; + fp->_lbfsize = 0; + } + fp->_flags |= __SRD; + } + else + { + /* + * We were reading. If there is an ungetc buffer, + * we must have been reading from that. Drop it, + * restoring the previous buffer (if any). If there + * is anything in that buffer, return. + */ + if (HASUB (fp)) + { + FREEUB (fp); + if ((fp->_r = fp->_ur) != 0) + { + fp->_p = fp->_up; + return 0; + } + } + } + + if (fp->_bf._base == NULL) + __smakebuf (fp); + + /* + * Before reading from a line buffered or unbuffered file, + * flush all line buffered output files, per the ANSI C + * standard. + */ + + if (fp->_flags & (__SLBF | __SNBF)) + (void) _fwalk (fp->_data, lflush); + fp->_p = fp->_bf._base; + fp->_r = (*fp->_read) (fp->_cookie, (char *) fp->_p, fp->_bf._size); + fp->_flags &= ~__SMOD; /* buffer contents are again pristine */ + if (fp->_r <= 0) + { + if (fp->_r == 0) + fp->_flags |= __SEOF; + else + { + fp->_r = 0; + fp->_flags |= __SERR; + } + return EOF; + } + return 0; +} |