Re: [PATCH RESEND 1/2] perf string: Add strcmp_prefix()

["liwei (GF)" <liwei391@huawei.com>]

On 2022/3/23 5:22, Arnaldo Carvalho de Melo wrote:
> Em Fri, Mar 18, 2022 at 05:22:44PM +0800, Wei Li escreveu:
>> Add a helper to check whether a string has the given prefix.
>> This function is stolen from fs/xattr.c
> 
> Can't you use strstarts()? See tools/include/linux/string.h.
> 

Sorry, i haven't known that before, will use strstarts() in v2.

Thanks,
Wei

>  
>> Signed-off-by: Wei Li <liwei391@huawei.com>
>> ---
>>  tools/perf/util/string.c  | 17 +++++++++++++++++
>>  tools/perf/util/string2.h |  1 +
>>  2 files changed, 18 insertions(+)
>>
>> diff --git a/tools/perf/util/string.c b/tools/perf/util/string.c
>> index f6d90cdd9225..0ed3e2d0b70f 100644
>> --- a/tools/perf/util/string.c
>> +++ b/tools/perf/util/string.c
>> @@ -209,6 +209,23 @@ int strtailcmp(const char *s1, const char *s2)
>>  	return 0;
>>  }
>>  
>> +/**
>> + * strcmp_prefix - check string for given prefix
>> + * @str: the target string to check
>> + * @prefix: the given prefix to match
>> + *
>> + * Return the rest string in @str if @str has the given @prefix, return NULL
>> + * otherwise.
>> + */
>> +const char *strcmp_prefix(const char *str, const char *prefix)
>> +{
>> +	while (*prefix && *str == *prefix) {
>> +		str++;
>> +		prefix++;
>> +	}
>> +	return *prefix ? NULL : str;
>> +}
>> +
>>  char *asprintf_expr_inout_ints(const char *var, bool in, size_t nints, int *ints)
>>  {
>>  	/*
>> diff --git a/tools/perf/util/string2.h b/tools/perf/util/string2.h
>> index 56c30fef9682..58929ad928f7 100644
>> --- a/tools/perf/util/string2.h
>> +++ b/tools/perf/util/string2.h
>> @@ -20,6 +20,7 @@ static inline bool strisglob(const char *str)
>>  	return strpbrk(str, "*?[") != NULL;
>>  }
>>  int strtailcmp(const char *s1, const char *s2);
>> +const char *strcmp_prefix(const char *str, const char *prefix);
>>  
>>  char *asprintf_expr_inout_ints(const char *var, bool in, size_t nints, int *ints);
>>  
>> -- 
>> 2.25.1
>