diff options
Diffstat (limited to 'release/src/router/busybox/miscutils/readahead.c')
-rw-r--r-- | release/src/router/busybox/miscutils/readahead.c | 40 |
1 files changed, 40 insertions, 0 deletions
diff --git a/release/src/router/busybox/miscutils/readahead.c b/release/src/router/busybox/miscutils/readahead.c new file mode 100644 index 00000000..fb71ce85 --- /dev/null +++ b/release/src/router/busybox/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; +} |