2002-04-29 Jeff Johnston <jjohnstn@redhat.com>

        *  libc/include/sys/unistd.h (pread, pwrite): Added prototypes.
        *  libc/unix/Makefile.am: Add pread.c and pwrite.c.
        *  libc/sys/linux/Makefile.am: Add pread64.c and pwrite64.c.
        *  libc/sys/linux/Makefile.in: Regenerated.
        *  libc/unix/Makefile.in: Ditto.
        *  libc/sys/linux/pread64.c: New file.
        *  libc/sys/linux/pwrite64.c: Ditto.
        *  libc/unix/pread.c: Ditto.
        *  libc/unix/pwrite.c: Ditto.

1 files changed, 62 insertions, 0 deletions

diff --git a/newlib/libc/sys/linux/pread64.c b/newlib/libc/sys/linux/pread64.c
new file mode 100644
index 000000000..c6d15f91d
--- /dev/null
+++ b/newlib/libc/sys/linux/pread64.c
@@ -0,0 +1,62 @@
+/*
+FUNCTION
+<<pread64>>---read a large file from specified position
+
+INDEX
+	pread64
+
+ANSI_SYNOPSIS
+	#include <unistd.h>
+	ssize_t pread64(int <[fd]>, void *<[buf]>, size_t <[n]>, loff_t <[off]>);
+
+TRAD_SYNOPSIS
+	#include <unistd.h>
+	ssize_t pread64(<[fd]>, <[buf]>, <[n]>, <[off]>)
+	int <[fd]>;
+	void *<[buf]>;
+	size_t <[n]>;
+	loff_t <[off]>;
+
+DESCRIPTION
+The <<pread64>> function is similar to <<pread>>.  The only difference is
+that it operates on large files and so takes a 64-bit offset.  Like <<pread>>>,
+the file position is unchanged by the function (i.e. the file position
+is the same before and after a call to <<pread>>).
+
+RETURNS
+<<pread64>> returns the number of bytes read or <<-1>> if failure occurred.
+
+PORTABILITY
+<<pread64>> is an EL/IX extension.
+
+Supporting OS subroutine required: <<read64>>, <<lseek64>>.
+*/
+
+#include <_ansi.h>
+#include <unistd.h>
+#include <reent.h>
+
+ssize_t
+_DEFUN (pread64, (fd, buf, n, off),
+     int fd _AND
+     _PTR buf _AND
+     size_t n _AND
+     loff_t off)
+{
+  loff_t cur_pos;
+  _READ_WRITE_RETURN_TYPE num_read;
+  
+  if ((cur_pos = lseek64 (fd, 0, SEEK_CUR)) == (loff_t)-1)
+    return -1;
+
+  if (lseek64 (fd, off, SEEK_SET) == (loff_t)-1)
+    return -1;
+
+  num_read = read64 (fd, buf, n);
+
+  if (lseek64 (fd, cur_pos, SEEK_SET) == (loff_t)-1)
+    return -1;
+
+  return (ssize_t)num_read;
+}
+