| /* 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 source tree. |
| */ |
| |
| //usage:#define readahead_trivial_usage |
| //usage: "[FILE]..." |
| //usage:#define readahead_full_usage "\n\n" |
| //usage: "Preload FILEs to RAM" |
| |
| #include "libbb.h" |
| |
| int readahead_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; |
| int readahead_main(int argc UNUSED_PARAM, char **argv) |
| { |
| int retval = EXIT_SUCCESS; |
| |
| if (!argv[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; |
| } |