extern char **guestfs_head_n (guestfs_h *handle, int nrlines, const char *path);
extern char **guestfs_tail (guestfs_h *handle, const char *path);
extern char **guestfs_tail_n (guestfs_h *handle, int nrlines, const char *path);
extern char **guestfs_head_n (guestfs_h *handle, int nrlines, const char *path);
extern char **guestfs_tail (guestfs_h *handle, const char *path);
extern char **guestfs_tail_n (guestfs_h *handle, int nrlines, const char *path);