[pacman-dev] [PATCH 2/4] Change sprintf function using for snprintf

[Xavier]

On Sun, Oct 18, 2009 at 6:03 AM, Laszlo Papp <djszapi2 at gmail.com> wrote:
>        * Size examined str* function usage is a common coding practice, because it's
>        more safer to avoid breakage while using str* functions.
>
> Signed-off-by: Laszlo Papp <djszapi at archlinux.us>
> ---
>  lib/libalpm/add.c      |    4 ++--
>  lib/libalpm/be_files.c |   10 +++++-----
>  lib/libalpm/conflict.c |    2 +-
>  lib/libalpm/db.c       |    4 ++--
>  lib/libalpm/trans.c    |    2 +-
>  lib/libalpm/util.c     |   16 +++++++++-------
>  src/pacman/sync.c      |    2 +-
>  src/pacman/util.c      |    2 +-
>  8 files changed, 22 insertions(+), 20 deletions(-)
>
> diff --git a/lib/libalpm/add.c b/lib/libalpm/add.c
> index ebcd6a5..209c38e 100644
> --- a/lib/libalpm/add.c
> +++ b/lib/libalpm/add.c
> @@ -311,7 +311,7 @@ static int extract_single_file(struct archive *archive,
>                        size_t backup_len = strlen(oldbackup) + 34;
>                        MALLOC(backup, backup_len, RET_ERR(PM_ERR_MEMORY, -1));
>
> -                       sprintf(backup, "%s\t%s", oldbackup, hash_pkg);
> +                       snprintf(backup, backup_len, "%s\t%s", oldbackup, hash_pkg);

I don't think this provides us any extra safety, because we already
compute exactly the size of the destination and allocate that memory.

I think it makes more sense where we define a fixed array, like char
path[PATH_MAX], and we then copy strings of different size to it :
src/pacman/pacman.c:                            snprintf(path,
PATH_MAX, "%s%s", alpm_option_get_root(), DBPATH + 1);
src/pacman/pacman.c:                            snprintf(path,
PATH_MAX, "%s%s", alpm_option_get_root(), LOGFILE + 1);