+/*-
+ * Copyright (c) 1990 The Regents of the University of California.
+ * All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Chris Torek.
+ *
+ * %sccs.include.redist.c%
+ */
+
+#if defined(LIBC_SCCS) && !defined(lint)
+static char sccsid[] = "@(#)fvwrite.c 5.1 (Berkeley) %G%";
+#endif /* LIBC_SCCS and not lint */
+
+#include <stdio.h>
+#include <string.h>
+#include "local.h"
+#include "fvwrite.h"
+
+/*
+ * Write some memory regions. Return zero on success, EOF on error.
+ *
+ * This routine is large and unsightly, but most of the ugliness due
+ * to the three different kinds of output buffering is handled here.
+ */
+__sfvwrite(fp, uio)
+ register FILE *fp;
+ register struct __suio *uio;
+{
+ register size_t len;
+ register char *p;
+ register struct __siov *iov;
+ register int w, s;
+ char *nl;
+ int nlknown, nldist;
+
+ if ((len = uio->uio_resid) == 0)
+ return (0);
+ /* make sure we can write */
+ if (cantwrite(fp))
+ return (EOF);
+
+#define MIN(a, b) ((a) < (b) ? (a) : (b))
+#define COPY(n) (void) memcpy((void *)fp->_p, (void *)p, (size_t)(n));
+
+ iov = uio->uio_iov;
+ len = 0;
+#define GETIOV(extra_work) \
+ while (len == 0) { \
+ extra_work; \
+ p = iov->iov_base; \
+ len = iov->iov_len; \
+ iov++; \
+ }
+ if (fp->_flags & __SNBF) {
+ /*
+ * Unbuffered: write up to BUFSIZ bytes at a time.
+ */
+ do {
+ GETIOV(;);
+ w = (*fp->_write)(fp->_cookie, p, MIN(len, BUFSIZ));
+ if (w <= 0)
+ goto err;
+ p += w;
+ len -= w;
+ } while ((uio->uio_resid -= w) != 0);
+ } else if ((fp->_flags & __SLBF) == 0) {
+ /*
+ * Fully buffered: fill partially full buffer, if any,
+ * and then flush. If there is no partial buffer, write
+ * one _bf._size byte chunk directly (without copying).
+ *
+ * String output is a special case: write as many bytes
+ * as fit, but pretend we wrote everything. This makes
+ * snprintf() return the number of bytes needed, rather
+ * than the number used, and avoids its write function
+ * (so that the write function can be invalid).
+ */
+ do {
+ GETIOV(;);
+ w = fp->_w;
+ if (fp->_flags & __SSTR) {
+ if (len < w)
+ w = len;
+ COPY(w); /* copy MIN(fp->_w,len), */
+ fp->_w -= w;
+ fp->_p += w;
+ w = len; /* but pretend copied all */
+ } else if (fp->_p > fp->_bf._base && len > w) {
+ /* fill and flush */
+ COPY(w);
+ /* fp->_w -= w; */ /* unneeded */
+ fp->_p += w;
+ if (fflush(fp))
+ goto err;
+ } else if (len >= (w = fp->_bf._size)) {
+ /* write directly */
+ w = (*fp->_write)(fp->_cookie, p, w);
+ if (w <= 0)
+ goto err;
+ } else {
+ /* fill and done */
+ w = len;
+ COPY(w);
+ fp->_w -= w;
+ fp->_p += w;
+ }
+ p += w;
+ len -= w;
+ } while ((uio->uio_resid -= w) != 0);
+ } else {
+ /*
+ * Line buffered: like fully buffered, but we
+ * must check for newlines. Compute the distance
+ * to the first newline (including the newline),
+ * or `infinity' if there is none, then pretend
+ * that the amount to write is MIN(len,nldist).
+ */
+ nlknown = 0;
+ do {
+ GETIOV(nlknown = 0);
+ if (!nlknown) {
+ nl = memchr((void *)p, '\n', len);
+ nldist = nl ? nl + 1 - p : len + 1;
+ nlknown = 1;
+ }
+ s = MIN(len, nldist);
+ w = fp->_w + fp->_bf._size;
+ if (fp->_p > fp->_bf._base && s > w) {
+ COPY(w);
+ /* fp->_w -= w; */
+ fp->_p += w;
+ if (fflush(fp))
+ goto err;
+ } else if (s >= (w = fp->_bf._size)) {
+ w = (*fp->_write)(fp->_cookie, p, w);
+ if (w <= 0)
+ goto err;
+ } else {
+ w = s;
+ COPY(w);
+ fp->_w -= w;
+ fp->_p += w;
+ }
+ if ((nldist -= w) == 0) {
+ /* copied the newline: flush and forget */
+ if (fflush(fp))
+ goto err;
+ nlknown = 0;
+ }
+ p += w;
+ len -= w;
+ } while ((uio->uio_resid -= w) != 0);
+ }
+ return (0);
+
+err:
+ fp->_flags |= __SERR;
+ return (EOF);
+}
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