1 files changed, 67 insertions, 0 deletions
diff --git a/src/unistd.c b/src/unistd.c
new file mode 100644
index 0000000..219e9ec
--- /dev/null
+++ b/src/unistd.c
@@ -0,0 +1,67 @@
+/*
+ * Copyright 2015 Vincent Sanders <vince@netsurf-browser.org>
+ *
+ * This file is part of libnsutils.
+ *
+ * Licensed under the MIT License,
+ *                http://www.opensource.org/licenses/mit-license.php
+ */
+
+/**
+ * \file
+ * unistd style operations.
+ */
+
+#include <unistd.h>
+#include <errno.h>
+
+#include "nsutils/unistd.h"
+
+/* exported interface documented in nsutils/unistd.h */
+ssize_t nsu_pwrite(int fd, const void *buf, size_t count, off_t offset)
+{
+#if defined(__riscos) || defined(__amiga)
+        off_t sk;
+
+        sk = lseek(fd, offset, SEEK_SET);
+        if (sk == (off_t)-1) {
+#if defined(__amiga)
+                /* amigaos cannot seek past the end of the existing file so use
+                 * ftruncate to make the file long enough and retry the seek.
+                 */
+                int ret;
+                if (errno == ESPIPE) {
+                        ret = ftruncate(fd, offset);
+                        if (ret == -1) {
+                                return -1;
+                        }
+                        sk = lseek(fd, offset, SEEK_SET);
+                        if (sk == (off_t)-1) {
+                                return -1;
+                        }
+                } else
+#endif
+                return -1;
+        }
+        return write(fd, buf, count);
+#else
+        return pwrite(fd, buf, count, offset);
+#endif
+}
+
+/* exported interface documented in nsutils/unistd.h */
+ssize_t nsu_pread(int fd, void *buf, size_t count, off_t offset)
+{
+#if defined(__riscos)
+        off_t sk;
+
+        sk = lseek(fd, offset, SEEK_SET);
+        if (sk == -1) {
+                return (off_t)-1;
+        }
+        return read(fd, buf, count);
+#else
+        return pread(fd, buf, count, offset);
+#endif
+
+}