-/* Read LEN bytes at PTR from descriptor DESC, retrying if necessary.
+/* safe-read.c -- an interface to read that retries after interrupts
+ Copyright (C) 1993, 1994, 1998 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 program; if not, write to the Free Software Foundation,
+ Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ */
+
+#if HAVE_CONFIG_H
+# include <config.h>
+#endif
+
+#include <sys/types.h>
+
+#if HAVE_UNISTD_H
+# include <unistd.h>
+#endif
+
+#include <errno.h>
+#ifndef errno
+extern int errno;
+#endif
+
+#include "safe-read.h"
+
+/* Read LEN bytes at PTR from descriptor DESC, retrying if interrupted.
Return the actual number of bytes read, zero for EOF, or negative
for an error. */
-int
-safe_read (desc, ptr, len)
- int desc;
- char *ptr;
- int len;
+ssize_t
+safe_read (int desc, void *ptr, size_t len)
{
- int n_remaining;
+ ssize_t n_chars;
+
+ if (len <= 0)
+ return len;
- n_remaining = len;
- while (n_remaining > 0)
- {
- int n_chars = read (desc, ptr, n_remaining);
- if (n_chars < 0)
- {
#ifdef EINTR
- if (errno == EINTR)
- continue;
-#endif
- return n_chars;
- }
- if (n_chars == 0)
- break;
- ptr += n_chars;
- n_remaining -= n_chars;
+ do
+ {
+ n_chars = read (desc, ptr, len);
}
- return len - n_remaining;
+ while (n_chars < 0 && errno == EINTR);
+#else
+ n_chars = read (desc, ptr, len);
+#endif
+
+ return n_chars;
}