This patch from Adam Heath <doogie@debian.org>, makes print_file
(used by cat, grep, sed, etc) quite a bit faster.
diff --git a/libbb/libbb.h b/libbb/libbb.h
index f34bee8..7ab0638 100644
--- a/libbb/libbb.h
+++ b/libbb/libbb.h
@@ -128,6 +128,7 @@
extern char *find_real_root_device_name(const char* name);
extern char *get_line_from_file(FILE *file);
extern void print_file(FILE *file);
+extern size_t copyfd(int fd1, int fd2);
extern int print_file_by_name(char *filename);
extern char process_escape_sequence(const char **ptr);
extern char *get_last_path_component(char *path);