diff options
Diffstat (limited to 'newlib/libc/stdio/wbuf.c')
-rw-r--r-- | newlib/libc/stdio/wbuf.c | 81 |
1 files changed, 81 insertions, 0 deletions
diff --git a/newlib/libc/stdio/wbuf.c b/newlib/libc/stdio/wbuf.c new file mode 100644 index 0000000..1106829 --- /dev/null +++ b/newlib/libc/stdio/wbuf.c @@ -0,0 +1,81 @@ +/* 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. + */ + +#if defined(LIBC_SCCS) && !defined(lint) +static char sccsid[] = "%W% (Berkeley) %G%"; +#endif /* LIBC_SCCS and not lint */ + +#include <stdio.h> +#include "local.h" +#include "fvwrite.h" + +/* + * Write the given character into the (probably full) buffer for + * the given file. Flush the buffer out if it is or becomes full, + * or if c=='\n' and the file is line buffered. + */ + +int +__swbuf (c, fp) + register int c; + register FILE *fp; +{ + register int n; + + /* Ensure stdio has been initialized. */ + + CHECK_INIT (fp); + + /* + * In case we cannot write, or longjmp takes us out early, + * make sure _w is 0 (if fully- or un-buffered) or -_bf._size + * (if line buffered) so that we will get called again. + * If we did not do this, a sufficient number of putc() + * calls might wrap _w from negative to positive. + */ + + fp->_w = fp->_lbfsize; + if (cantwrite (fp)) + return EOF; + c = (unsigned char) c; + + /* + * If it is completely full, flush it out. Then, in any case, + * stuff c into the buffer. If this causes the buffer to fill + * completely, or if c is '\n' and the file is line buffered, + * flush it (perhaps a second time). The second flush will always + * happen on unbuffered streams, where _bf._size==1; fflush() + * guarantees that putc() will always call wbuf() by setting _w + * to 0, so we need not do anything else. + */ + + n = fp->_p - fp->_bf._base; + if (n >= fp->_bf._size) + { + if (fflush (fp)) + return EOF; + n = 0; + } + fp->_w--; + *fp->_p++ = c; + if (++n == fp->_bf._size || (fp->_flags & __SLBF && c == '\n')) + if (fflush (fp)) + return EOF; + return c; +} |