1 files changed, 76 insertions, 0 deletions
diff --git a/string/strxfrm.c b/string/strxfrm.c
new file mode 100644
index 0000000000..cdca280e78
--- /dev/null
+++ b/string/strxfrm.c
@@ -0,0 +1,76 @@
+/* Copyright (C) 1991 Free Software Foundation, Inc.
+This file is part of the GNU C Library.
+
+The GNU C Library is free software; you can redistribute it and/or
+modify it under the terms of the GNU Library General Public License as
+published by the Free Software Foundation; either version 2 of the
+License, or (at your option) any later version.
+
+The GNU C Library 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
+Library General Public License for more details.
+
+You should have received a copy of the GNU Library General Public
+License along with the GNU C Library; see the file COPYING.LIB.  If
+not, write to the Free Software Foundation, Inc., 675 Mass Ave,
+Cambridge, MA 02139, USA.  */
+
+#include <ansidecl.h>
+#include <localeinfo.h>
+#include <stddef.h>
+#include <stdlib.h>
+#include <string.h>
+
+
+/* Transform SRC into a form such that the result of strcmp
+   on two strings that have been transformed by strxfrm is
+   the same as the result of strcoll on the two strings before
+   their transformation.  The transformed string is put in at
+   most N characters of DEST and its length is returned.  */
+size_t
+DEFUN(strxfrm, (dest, src, n), char *dest AND CONST char *src AND size_t n)
+{
+  CONST unsigned char *CONST values
+    = _collate_info != NULL ? _collate_info->values : NULL;
+  CONST unsigned char *CONST offsets
+    = _collate_info != NULL ? _collate_info->offsets : NULL;
+  register size_t done = 0;
+
+  while (*src != '\0')
+    {
+      CONST unsigned char c = *src++;
+
+      ++done;
+      if (offsets != NULL && offsets[c] != 0)
+	{
+	  ++done;
+	  if (offsets[c] == CHAR_MAX)
+	    ++done;
+	}
+      if (done < n && dest != NULL)
+	{
+	  if (values == NULL)
+	    *dest++ = c;
+	  else if (values[c] == UCHAR_MAX && offsets[c] == 0)
+	    /* This is a non-collating element.  Skip it.  */
+	    ;
+	  else if (values[c] == UCHAR_MAX && offsets[c] == CHAR_MAX)
+	    {
+	      /* This element collates lower than anything else.  */
+	      *dest++ = '\001';
+	      *dest++ = '\001';
+	      *dest++ = '\001';
+	    }
+	  else
+	    {
+	      *dest++ = values[c];
+	      *dest++ = offsets[c];
+	    }
+	}
+    }
+
+  if (dest != NULL)
+    *dest = '\0';
+  return done;
+}