On Fri, 2016-02-19 at 20:22 -0500, Jessica Yu wrote:
> Implement basic character sets for the '%[]' conversion specifier.
>
> The '%[]' conversion specifier matches a nonempty sequence of
> characters
> from the specified set of accepted (or with '^', rejected) characters
> between the brackets. The substring matched is to be made up of
> characters
> in (or not in) the set. This implementation differs from its glibc
> counterpart in that it does not support character ranges (e.g., 'a-z'
> or
> '0-9'), the hyphen '-' is *not* a special character, and the brackets
> themselves cannot be matched.
>
> Signed-off-by: Jessica Yu <j...@redhat.com>
> ---
> lib/vsprintf.c | 35 +++++++++++++++++++++++++++++++++++
> 1 file changed, 35 insertions(+)
>
> diff --git a/lib/vsprintf.c b/lib/vsprintf.c
> index 525c8e1..6ee3e7f 100644
> --- a/lib/vsprintf.c
> +++ b/lib/vsprintf.c
> @@ -2714,6 +2714,41 @@ int vsscanf(const char *buf, const char *fmt,
> va_list args)
> num++;
> }
> continue;
> + case '[':
> + {
> + char *s = (char *)va_arg(args, char *);
> + char set[U8_MAX] = { 0 };
Hmm... 255 on stack, not the best idea.
> + size_t (*op)(const char *str, const char
> *set);
> + size_t len = 0;
> + bool negate = (*(fmt) == '^');
> +
> + if (field_width == -1)
> + field_width = SHRT_MAX;
> +
> + op = negate ? &strcspn : &strspn;
> + if (negate)
> + fmt++;
> +
> + len = strcspn(fmt, "]");
> + /* invalid format; stop here */
> + if (!len)
> + return num;
> +
> + strncpy(set, fmt, len);
Perhaps here you may allocate memory on heap and copy the given set.
IIRC kstrndup() does this.
> + /* advance fmt past ']' */
> + fmt += len + 1;
> +
> + len = (*op)(str, set);
> + /* no matches */
> + if (!len)
> + return num;
> +
> + while (*str && len-- && field_width--)
> + *s++ = *str++;
> + *s = '\0';
> + num++;
> + }
> + continue;
> case 'o':
> base = 8;
> break;
--
Andy Shevchenko <andriy.shevche...@linux.intel.com>
Intel Finland Oy
