[PATCH v4 1/4] eal: add basename function for common path manipulation

[Stephen Hemminger]

On Thu, 31 Jul 2025 16:00:38 +0000
Bruce Richardson <bruce.richardson at intel.com> wrote:

> There is no standard, cross-platform function to get the basename of a
> file path across all the supported DPDK platforms, Linux, BSD and
> Windows. Both Linux and BSD have a "basename" function in standard
> library, except:
> * Linux has two different basename functions, a POSIX version (which may
>   or may not modify args), and a GNU one which is guaranteed *not* to
>   modify the input arg and returns pointer to internal storage.
> * FreeBSD has just the one basename function, but, to be different, it is
>   guaranteed *always* to modify the argument and re-use it for output.
> * Windows just doesn't have a basename function, but provides _split_path
>   as a similar function, but with many differences over basename, e.g.
>   splitting off extension, returning empty basename if path ends in "/"
>   etc. etc.
> 
> Therefore, rather than just trying to implement basename for windows,
> which opens the question as to whether to emulate GNU and *never* modify
> arg, or emulate BSD and *always* modify arg, this patchset introduces
> "rte_basename" which should have defined behaviour on all platforms. The
> patch also introduces a set of test cases to confirm consistent behaviour
> on all platforms too.
> 
> The behaviour is as in doxygen docs. Essentially:
> - does not modify input path buffer
> - returns output in a separate output buffer
> - uses snprintf and strlcpy style return value to indicate truncation
> 
> Signed-off-by: Bruce Richardson <bruce.richardson at intel.com>

What about existing uses of basename()

0 main.c                  main                       553 char *token = strtok(basename(rst_path),
                                                         ".");
1 process.h               get_current_prefix         220 snprintf(prefix, size, "%s",
                                                         basename(dirname(buf)));
2 mlx5_common_auxiliary.c mlx5_auxiliary_get_pci_str  85 base = basename(sysfs_pci);
3 idxd_bus.c              is_for_this_process_use    271 prefix = basename(runtime_dir);
4 bnxt_tf_pmd_shim.c      ulp_pmd_get_mac_by_pci     156 intf_name = basename(gres.gl_pathv[0]);
5 eal_common_proc.c       rte_mp_channel_init        628 strlcpy(mp_filter, basename(path),
                                                         sizeof(mp_filter));