* rw.c: new file, implementing C part of module (ice-9 rw).

(scm_read_string_x_partial): moved from ioext.c
	(scm_init_rw): new proc.
	* rw.h: new file.
	init.c: include rw.h and call scm_init_rw.
	Makefile.am: include rw.c and rw.h.

libguile/rw.c

@@ -0,0 +1,178 @@
+/* 	Copyright (C) 2001 Free Software Foundation, Inc.
+ * 
+ * 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 2, 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 software; see the file COPYING.  If not, write to
+ * the Free Software Foundation, Inc., 59 Temple Place, Suite 330,
+ * Boston, MA 02111-1307 USA
+ *
+ * As a special exception, the Free Software Foundation gives permission
+ * for additional uses of the text contained in its release of GUILE.
+ *
+ * The exception is that, if you link the GUILE library with other files
+ * to produce an executable, this does not by itself cause the
+ * resulting executable to be covered by the GNU General Public License.
+ * Your use of that executable is in no way restricted on account of
+ * linking the GUILE library code into it.
+ *
+ * This exception does not however invalidate any other reasons why
+ * the executable file might be covered by the GNU General Public License.
+ *
+ * This exception applies only to the code released by the
+ * Free Software Foundation under the name GUILE.  If you copy
+ * code from other Free Software Foundation releases into a copy of
+ * GUILE, as the General Public License permits, the exception does
+ * not apply to the code that you add in this way.  To avoid misleading
+ * anyone as to the status of such modified files, you must delete
+ * this exception notice from them.
+ *
+ * If you write modifications of your own for GUILE, it is your choice
+ * whether to permit this exception to apply to your modifications.
+ * If you do not wish that, delete this exception notice.  */
+
+
+
+/* This is the C part of the (ice-9 rw) module.  */
+
+#include <errno.h>
+
+#include "libguile/_scm.h"
+#include "libguile/fports.h"
+#include "libguile/ports.h"
+#include "libguile/root.h"
+#include "libguile/rw.h"
+#include "libguile/strings.h"
+#include "libguile/validate.h"
+
+#ifdef HAVE_UNISTD_H
+#include <unistd.h>
+#endif
+
+
+
+#if defined (EAGAIN)
+#define SCM_MAYBE_EAGAIN || errno == EAGAIN
+#else
+#define SCM_MAYBE_EAGAIN
+#endif
+
+#if defined (EWOULDBLOCK)
+#define SCM_MAYBE_EWOULDBLOCK || errno == EWOULDBLOCK
+#else
+#define SCM_MAYBE_EWOULDBLOCK
+#endif
+
+/* MAYBE there is EAGAIN way of defining this macro but now I EWOULDBLOCK.  */
+#define SCM_EBLOCK(errno) \
+   (0 SCM_MAYBE_EAGAIN SCM_MAYBE_EWOULDBLOCK)
+
+SCM_DEFINE (scm_read_string_x_partial, "read-string!/partial", 1, 3, 0,
+	    (SCM str, SCM port_or_fdes, SCM start, SCM end),
+	    "Read characters from an fport or file descriptor into a\n"
+	    "string @var{str}.  This procedure is scsh-compatible\n"
+	    "and can efficiently read large strings.  It will:\n\n"
+	    "@itemize\n"
+	    "@item\n"
+	    "attempt to fill the entire string, unless the @var{start}\n"
+	    "and/or @var{end} arguments are supplied.  i.e., @var{start}\n"
+	    "defaults to 0 and @var{end} defaults to\n"
+	    "@code{(string-length str)}\n"
+	    "@item\n"
+	    "use the current input port if @var{port_or_fdes} is not\n"
+	    "supplied.\n" 
+	    "@item\n"
+	    "read any characters that are currently available,\n"
+	    "without waiting for the rest (short reads are possible).\n\n"
+	    "@item\n"
+	    "wait for as long as it needs to for the first character to\n"
+	    "become available, unless the port is in non-blocking mode\n"
+	    "@item\n"
+	    "return @code{#f} if end-of-file is encountered before reading\n"
+            "any characters, otherwise return the number of characters\n"
+	    "read.\n"
+	    "@item\n"
+	    "return 0 if the port is in non-blocking mode and no characters\n"
+	    "are immediately available.\n"
+	    "@item\n"
+	    "return 0 if the request is for 0 bytes, with no\n"
+	    "end-of-file check\n"
+	    "@end itemize")
+#define FUNC_NAME s_scm_read_string_x_partial
+{
+  char *dest;
+  long read_len;
+  long chars_read = 0;
+  int fdes;
+
+  {
+    long offset;
+    long last;
+
+    SCM_VALIDATE_SUBSTRING_SPEC_COPY (1, str, dest, 3, start, offset,
+				      4, end, last);
+    dest += offset;
+    read_len = last - offset;
+  }
+
+  if (SCM_INUMP (port_or_fdes))
+    fdes = SCM_INUM (port_or_fdes);
+  else
+    {
+      SCM port = SCM_UNBNDP (port_or_fdes) ? scm_cur_inp : port_or_fdes;
+
+      SCM_VALIDATE_OPFPORT (2, port);
+      SCM_VALIDATE_INPUT_PORT (2, port);
+
+      /* if there's anything in the port buffers, use it, but then
+	 don't touch the file descriptor.  otherwise the
+	 "return immediately if something is available" rule may
+	 be violated.  */
+      chars_read = scm_take_from_input_buffers (port, dest, read_len);
+      fdes = SCM_FPORT_FDES (port);
+    }
+
+  if (chars_read == 0 && read_len > 0) /* don't confuse read_len == 0 with
+					  EOF.  */
+    {
+      SCM_SYSCALL (chars_read = read (fdes, dest, read_len));
+      if (chars_read == -1)
+	{
+	  if (SCM_EBLOCK (errno))
+	    chars_read = 0;
+	  else
+	    SCM_SYSERROR;
+        }
+      else if (chars_read == 0)
+	return SCM_BOOL_F;
+    }
+  return scm_long2num (chars_read);
+}
+#undef FUNC_NAME
+
+void 
+scm_init_rw ()
+{
+  SCM rw_module = scm_make_module (scm_read_0str ("(ice-9 rw)"));
+  SCM old_module = scm_set_current_module (rw_module);
+
+#ifndef SCM_MAGIC_SNARFER
+#include "libguile/rw.x"
+#endif
+
+  scm_set_current_module (old_module);
+}
+
+/*
+  Local Variables:
+  c-file-style: "gnu"
+  End:
+*/