Re: [RFC PATCH 1/3] Add string parsing function get_next_ulong

[Randy Dunlap <rdunlap@xenotime.net>]

On Wed, 27 Apr 2011 18:16:45 +0200 Stefan Assmann wrote:

> Adding this function to allow easy parsing of unsigned long values from the
> beginning of strings. Convenience function to parse pointers from the kernel
> command line.
> 
> Signed-off-by: Stefan Assmann <sassmann@kpanic.de>
> ---
>  include/linux/kernel.h |    1 +
>  lib/cmdline.c          |   35 +++++++++++++++++++++++++++++++++++
>  2 files changed, 36 insertions(+), 0 deletions(-)
> 
> diff --git a/include/linux/kernel.h b/include/linux/kernel.h
> index 2fe6e84..b6ded39 100644
> --- a/include/linux/kernel.h
> +++ b/include/linux/kernel.h
> @@ -218,6 +218,7 @@ extern int vsscanf(const char *, const char *, va_list)
>  
>  extern int get_option(char **str, int *pint);
>  extern char *get_options(const char *str, int nints, int *ints);
> +extern int get_next_ulong(char **str, unsigned long *val, char sep, int base);
>  extern unsigned long long memparse(const char *ptr, char **retptr);
>  
>  extern int core_kernel_text(unsigned long addr);
> diff --git a/lib/cmdline.c b/lib/cmdline.c
> index f5f3ad8..82a6616 100644
> --- a/lib/cmdline.c
> +++ b/lib/cmdline.c
> @@ -114,6 +114,41 @@ char *get_options(const char *str, int nints, int *ints)
>  }
>  
>  /**
> + *	get_next_ulong - Parse unsigned long at the beginning of a string
> + *	@strp: (output) String to be parsed

                ^ input/output

> + *	@val: (output) unsigned long carrying the result
> + *	@sep: character specifying the separator
> + *	@base: number system of the parsed value
> + *
> + *	This function parses an unsigned long value at the beginning of a
> + *	string. The string may begin with a separator or an unsigned long
> + *	value.
> + *	After the function is run val will contain the parsed value and strp

                                  @val                                  @strp

> + *	will point to the character *after* the parsed unsigned long.
> + *
> + *	In the error case 0 is returned, val and *strp stay unaltered.

                                         @val and @strp

> + *	Otherwise return 1.
> + */
> +int get_next_ulong(char **strp, unsigned long *val, char sep, int base)
> +{
> +	char *tmp;
> +
> +	if (!strp || !(*strp))
> +		return 0;
> +
> +	tmp = *strp;
> +	if (*tmp == sep)
> +		tmp++;
> +
> +	*val = simple_strtoul(tmp, strp, base);
> +
> +	if (tmp == *strp)
> +		return 0; /* no new value parsed */
> +	else
> +		return 1;
> +}
> +
> +/**
>   *	memparse - parse a string with mem suffixes into a number
>   *	@ptr: Where parse begins
>   *	@retptr: (output) Optional pointer to next char after parse completes
> -- 


---
~Randy
*** Remember to use Documentation/SubmitChecklist when testing your code ***

--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org.  For more info on Linux MM,
see: http://www.linux-mm.org/ .
Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>