80 lines
2.2 KiB
C
80 lines
2.2 KiB
C
#if !defined(lint) && defined(SCCSIDS)
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static char sccsid[] = "@(#)fwrite.c 1.1 94/10/31 SMI"; /* from S5R2 3.6 */
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#endif
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/*LINTLIBRARY*/
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/*
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* This version writes directly to the buffer rather than looping on putc.
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* Ptr args aren't checked for NULL because the program would be a
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* catastrophic mess anyway. Better to abort than just to return NULL.
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*
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* This version does buffered writes larger than BUFSIZ directly, when
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* the buffer is empty.
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*/
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#include <stdio.h>
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#include "stdiom.h"
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#include <errno.h>
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#define MIN(x, y) (x < y ? x : y)
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extern char *memcpy();
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int
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fwrite(ptr, size, count, iop)
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char *ptr;
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int size, count;
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register FILE *iop;
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{
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register unsigned nleft;
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register int n;
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register unsigned char *cptr, *bufend;
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register unsigned char *prev_ptr;
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if (size <= 0 || count <= 0 || _WRTCHK(iop)) {
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#ifdef POSIX
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errno = EBADF;
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#endif POSIX
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return (0);
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}
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bufend = iop->_base + iop->_bufsiz;
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nleft = count*size;
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/* if the file is unbuffered, or if the iop->ptr = iop->base, and there
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is > BUFSZ chars to write, we can do a direct write */
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prev_ptr = iop->_ptr;
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if (iop->_base >= iop->_ptr) { /*this covers the unbuffered case, too*/
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if (((iop->_flag & _IONBF) != 0) || (nleft >= BUFSIZ)) {
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if ((n=write(fileno(iop),ptr,nleft)) != nleft)
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{
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iop->_flag |= _IOERR;
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n = (n >= 0) ? n : 0;
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}
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return n/size;
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}
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}
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/* Put characters in the buffer */
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/* note that the meaning of n when just starting this loop is
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irrelevant. It is defined in the loop */
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for (; ; ptr += n) {
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while ((n = bufend - (cptr = iop->_ptr)) <= 0) /* full buf */
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if (_xflsbuf(iop) == EOF)
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return (count - (nleft + size - 1)/size);
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n = MIN(nleft, n);
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(void) memcpy((char *) cptr, ptr, n);
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iop->_cnt -= n;
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iop->_ptr += n;
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_BUFSYNC(iop);
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/* done; flush if linebuffered with a newline */
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if ((nleft -= n) == 0) {
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if (iop->_flag & (_IOLBF | _IONBF)) {
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if ((iop->_flag & _IONBF) || (memchr(prev_ptr,
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'\n',iop->_ptr - prev_ptr) != NULL)) {
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(void) _xflsbuf(iop);
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}
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}
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return (count);
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}
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}
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}
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