strstr and strchr

strstr and strchr

[Fundu]

looks strange to me 
if i look for a str using strstr it gives me the starting index of the string. so let say if i'm looking for "firstName" in "<Info firstName=\"sam\" lastName=\"Smith\" />" using 
strstr(ptr, "firstName");  i would get the pointer pointing to the f in firstName.


whereas if i use strchr and using a slight variation of the string mentioned above(suing ' instead of ")  "<Info firstName='sam' lastName='Smith'/>" 
strchr(ptr, "'") returns a pointer pointing after the ' 
so a printf("[%s]\n", strchr(ptr, "'"));
would print [  lastName='Smith'/>]  

which doesn't make sense to me.

can someone shed some light. TIA !


      

Re: strstr and strchr

[Bert Wesarg]

On Tue, Feb 17, 2009 at 09:30, Fundu <fundu_1999@yahoo.com> wrote:
> looks strange to me
> if i look for a str using strstr it gives me the starting index of the string. so let say if i'm looking for "firstName" in "<Info firstName=\"sam\" lastName=\"Smith\" />" using
> strstr(ptr, "firstName");  i would get the pointer pointing to the f in firstName.
>
>
> whereas if i use strchr and using a slight variation of the string mentioned above(suing ' instead of ")  "<Info firstName='sam' lastName='Smith'/>"
> strchr(ptr, "'") returns a pointer pointing after the '
strchr() takes a int as second argument, not a 'char *', I suggest trying:

strchr(ptr, '\'')

> so a printf("[%s]\n", strchr(ptr, "'"));
> would print [  lastName='Smith'/>]
>
> which doesn't make sense to me.
>
> can someone shed some light. TIA !

Re: strstr and strchr

[Fundu]

Bert,
i did try that but got same response. 


--- On Tue, 2/17/09, Bert Wesarg <bert.wesarg@googlemail.com> wrote:

> From: Bert Wesarg <bert.wesarg@googlemail.com>
> Subject: Re: strstr and strchr
> To: fundu_1999@yahoo.com
> Cc: linux-c-programming@vger.kernel.org
> Date: Tuesday, February 17, 2009, 2:48 AM
> On Tue, Feb 17, 2009 at 09:30, Fundu
> <fundu_1999@yahoo.com> wrote:
> > looks strange to me
> > if i look for a str using strstr it gives me the
> starting index of the string. so let say if i'm looking
> for "firstName" in "<Info
> firstName=\"sam\"
> lastName=\"Smith\" />" using
> > strstr(ptr, "firstName");  i would get the
> pointer pointing to the f in firstName.
> >
> >
> > whereas if i use strchr and using a slight variation
> of the string mentioned above(suing ' instead of ")
>  "<Info firstName='sam'
> lastName='Smith'/>"
> > strchr(ptr, "'") returns a pointer
> pointing after the '
> strchr() takes a int as second argument, not a 'char
> *', I suggest trying:
> 
> strchr(ptr, '\'')
> 
> > so a printf("[%s]\n", strchr(ptr,
> "'"));
> > would print [  lastName='Smith'/>]
> >
> > which doesn't make sense to me.
> >
> > can someone shed some light. TIA !
> --
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Re: strstr and strchr

[Bert Wesarg]

On Tue, Feb 17, 2009 at 12:52, Fundu <fundu_1999@yahoo.com> wrote:
> Bert,
> i did try that but got same response.
I'm not:

int
main(int ac, char *av[])
{
    char *str = "<Info firstName='sam' lastName='Smith' />";
    char *ptr = strchr(str, '\'');

    if (!ptr)
        return 1;

    printf("%s\n", str);
    printf("%*s^\n", (int)(ptr - str), "");

    return 0;
}

prints:

<Info firstName='sam' lastName='Smith' />
                ^

Re: strstr and strchr

[Bert Wesarg]

On Tue, Feb 17, 2009 at 12:58, Bert Wesarg <bert.wesarg@googlemail.com> wrote:
> On Tue, Feb 17, 2009 at 12:52, Fundu <fundu_1999@yahoo.com> wrote:
>> Bert,
>> i did try that but got same response.
> I'm not:
>
> int
> main(int ac, char *av[])
> {
>    char *str = "<Info firstName='sam' lastName='Smith' />";
>    char *ptr = strchr(str, '\'');
>
>    if (!ptr)
>        return 1;
>
>    printf("%s\n", str);
>    printf("%*s^\n", (int)(ptr - str), "");
>
>    return 0;
> }
>
> prints:
>
> <Info firstName='sam' lastName='Smith' />
>                ^
This looks probably wrong, because of malformed whitespace.