wcsnrtombs: Prepare for new module wwcsnrtombs.

[gnulib.git] / lib / wcsnrtombs-impl.h

diff --git a/lib/wcsnrtombs-impl.h b/lib/wcsnrtombs-impl.h
new file mode 100644 (file)
index 0000000..5ba63cc
--- /dev/null
+++ b/lib/wcsnrtombs-impl.h
@@ -0,0 +1,90 @@
+/* Convert wide string to string.
+   Copyright (C) 2008-2011 Free Software Foundation, Inc.
+   Written by Bruno Haible <bruno@clisp.org>, 2008.
+
+   This program is free software: you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
+
+size_t
+wcsnrtombs (char *dest, const wchar_t **srcp, size_t srclen, size_t len, mbstate_t *ps)
+{
+  if (ps == NULL)
+    ps = &_gl_wcsrtombs_state;
+  {
+    const wchar_t *src = *srcp;
+    size_t cur_max = MB_CUR_MAX;
+    char buf[64];
+
+    if (!(cur_max <= sizeof (buf)))
+      abort ();
+
+    if (dest != NULL)
+      {
+        char *destptr = dest;
+
+        for (; srclen > 0 && len > 0; src++, srclen--)
+          {
+            wchar_t wc = *src;
+            size_t ret = wcrtomb (len >= cur_max ? destptr : buf, wc, ps);
+
+            if (ret == (size_t)(-1))
+              goto bad_input;
+            if (!(ret <= cur_max))
+              abort ();
+            if (len < ret)
+              break;
+            if (len < cur_max)
+              memcpy (destptr, buf, ret);
+            if (wc == 0)
+              {
+                src = NULL;
+                /* Here mbsinit (ps).  */
+                break;
+              }
+            destptr += ret;
+            len -= ret;
+          }
+        *srcp = src;
+        return destptr - dest;
+      }
+    else
+      {
+        /* Ignore dest and len, don't store *srcp at the end, and
+           don't clobber *ps.  */
+        mbstate_t state = *ps;
+        size_t totalcount = 0;
+
+        for (; srclen > 0; src++, srclen--)
+          {
+            wchar_t wc = *src;
+            size_t ret = wcrtomb (buf, wc, &state);
+
+            if (ret == (size_t)(-1))
+              goto bad_input2;
+            if (wc == 0)
+              {
+                /* Here mbsinit (&state).  */
+                break;
+              }
+            totalcount += ret;
+          }
+        return totalcount;
+      }
+
+   bad_input:
+    *srcp = src;
+   bad_input2:
+    errno = EILSEQ;
+    return (size_t)(-1);
+  }
+}