[PATCH v2 1/7] string: add strtok/strtokv

[Ahmad Fatoum]

Hi,

On 9/9/25 3:18 PM, Tobias Waldekranz wrote:
> Add an implementation of libc's standard strtok(3), which is useful
> for tokenizing strings.

Nitpick: Only strtokv is implemented, but I think no need to resend,
Sascha can fix it up when applying.

> 
> Also, add a version that will collect all tokens from a string into an
> array, which is useful in situations where you need to know how many
> tokens there are, and when a token's relative position in the order is
> significant.
> 
> Signed-off-by: Tobias Waldekranz <tobias at waldekranz.com>

Reviewed-by: Ahmad Fatoum <a.fatoum at pengutronix.de>

> ---
> 
> Notes:
>     v1 -> v2:
>     - Tokeinize using strsep()+empty-token-check instead of strtok()
>     - Return array from strtokv() and pass count in an output pointer,
>       rather than the opposite.
> 
>  include/string.h |  1 +
>  lib/string.c     | 30 ++++++++++++++++++++++++++++++
>  2 files changed, 31 insertions(+)
> 
> diff --git a/include/string.h b/include/string.h
> index 71affe48b6..cb3492ba04 100644
> --- a/include/string.h
> +++ b/include/string.h
> @@ -8,6 +8,7 @@
>  void *mempcpy(void *dest, const void *src, size_t count);
>  int strtobool(const char *str, int *val);
>  char *strsep_unescaped(char **, const char *, char *);
> +char **strtokv(char *str, const char *delim, int *cntp);
>  char *stpcpy(char *dest, const char *src);
>  bool strends(const char *str, const char *postfix);
>  
> diff --git a/lib/string.c b/lib/string.c
> index 73637cd971..a55f989900 100644
> --- a/lib/string.c
> +++ b/lib/string.c
> @@ -593,6 +593,36 @@ char *strsep_unescaped(char **s, const char *ct, char *delim)
>          return sbegin;
>  }
>  
> +/**
> + * strtokv - split string into array of tokens based on a delimiter set
> + * @str:	string to split
> + * @delim:	set of delimiter characters
> + * @cntp:	number of tokens
> + *
> + * Split @str into non-empty tokens delimited by spans of characters
> + * from @delim, and store the numbers of tokens in @cntp.
> + *
> + * Return: The allocated array of tokens, which the caller is
> + * responsible for freeing.
> + */
> +char **strtokv(char *str, const char *delim, int *cntp)
> +{
> +	char *tok, **vec = NULL;
> +	int cnt = 0;
> +
> +	while ((tok = strsep(&str, delim))) {
> +		if (*tok == '\0')
> +			continue;
> +
> +		vec = xrealloc(vec, (cnt + 1) * sizeof(*vec));
> +		vec[cnt++] = tok;
> +	}
> +
> +	*cntp = cnt;
> +	return vec;
> +}
> +EXPORT_SYMBOL(strtokv);
> +
>  #ifndef __HAVE_ARCH_STRSWAB
>  /**
>   * strswab - swap adjacent even and odd bytes in %NUL-terminated string

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