[FFmpeg-devel] [PATCH V2 1/7] libavdevice/v4l2.c: fix build warning for [-Wformat-truncation=]

[Chad Fraleigh]

On 2/24/2021 10:38 PM, Guo, Yejun wrote:
> Here is the warning message:
> src/libavdevice/v4l2.c: In function ‘v4l2_get_device_list’:
> src/libavdevice/v4l2.c:1054:58: warning: ‘%s’ directive output may be truncated writing up to 255 bytes into a region of size 251 [-Wformat-truncation=]
>           snprintf(device_name, sizeof(device_name), "/dev/%s", entry->d_name);
>                                                            ^~
> src/libavdevice/v4l2.c:1054:9: note: ‘snprintf’ output between 6 and 261 bytes into a destination of size 256
>           snprintf(device_name, sizeof(device_name), "/dev/%s", entry->d_name);
>           ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> 
> Signed-off-by: Guo, Yejun <yejun.guo at intel.com>
> ---
>   libavdevice/v4l2.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/libavdevice/v4l2.c b/libavdevice/v4l2.c
> index 365bacd771..e11d10d20e 100644
> --- a/libavdevice/v4l2.c
> +++ b/libavdevice/v4l2.c
> @@ -1046,7 +1046,7 @@ static int v4l2_get_device_list(AVFormatContext *ctx, AVDeviceInfoList *device_l
>           return ret;
>       }
>       while ((entry = readdir(dir))) {
> -        char device_name[256];
> +        char device_name[512];

Is there a portable path max constant that would be better for cases 
like this, rather than just picking another arbitrary buffer size?


>   
>           if (!v4l2_is_v4l_dev(entry->d_name))
>               continue;
>