busybox: imported from http://www.busybox.net/downloads/busybox-1.13.3.tar.bz2busybox-1.13.3

Signed-off-by: Bjørn Mork <bjorn@mork.no>

1 files changed, 40 insertions, 0 deletions

diff --git a/miscutils/readahead.c b/miscutils/readahead.c
new file mode 100644
index 0000000..fb71ce8
--- /dev/null
+++ b/miscutils/readahead.c
@@ -0,0 +1,40 @@
+/* vi: set sw=4 ts=4: */
+/*
+ * readahead implementation for busybox
+ *
+ * Preloads the given files in RAM, to reduce access time.
+ * Does this by calling the readahead(2) system call.
+ *
+ * Copyright (C) 2006  Michael Opdenacker <michael@free-electrons.com>
+ *
+ * Licensed under GPLv2 or later, see file License in this tarball for details.
+ */
+
+#include "libbb.h"
+
+int readahead_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
+int readahead_main(int argc, char **argv)
+{
+	int retval = EXIT_SUCCESS;
+
+	if (argc == 1) bb_show_usage();
+
+	while (*++argv) {
+		int fd = open_or_warn(*argv, O_RDONLY);
+		if (fd >= 0) {
+			off_t len;
+			int r;
+
+			/* fdlength was reported to be unreliable - use seek */
+			len = xlseek(fd, 0, SEEK_END);
+			xlseek(fd, 0, SEEK_SET);
+			r = readahead(fd, 0, len);
+			close(fd);
+			if (r >= 0)
+				continue;
+		}
+		retval = EXIT_FAILURE;
+	}
+
+	return retval;
+}