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Hi,
I am trying to compare a char* with an unsigned char*.I have type cast
the later to char*.Now the problem is, the unsigned char* is populated
with recv() function over the socket and sometimes it containes junk.I
need to compare the received message over the socket with a particular
charecter 'r' to terminate the entire process.
Any help will be highly appreciated.The code snippet and my output is
as follows:

if(!(strcmp(message,"q"))){
Close(clntSocket);
exit(0);
}

output screen:

The received message is :q©

Length of the received message 1
q©

** Though I typed q, the received message has a junk charecter at its
end and hence the comparison dosn't work.but sometimes after two/three
failed times, the string is without any junk charecter.

Thanks.

Index wrote:
> I am trying to compare a char* with an unsigned char*.I have type cast
> the later to char*.Now the problem is, the unsigned char* is populated
> with recv() function over the socket and sometimes it containes junk.I
> need to compare the received message over the socket with a particular
> charecter 'r' to terminate the entire process.
> Any help will be highly appreciated.The code snippet and my output is
> as follows:
>
> if(!(strcmp(message,"q"))){
> Close(clntSocket);
> exit(0);
> }
>
> output screen:
>
> The received message is :q©
>
> Length of the received message 1
> q©
>
> ** Though I typed q, the received message has a junk charecter at its
> end and hence the comparison dosn't work.but sometimes after two/three
> failed times, the string is without any junk charecter.

You need to use 'strncmp' or simply compare the first character of
the message:

if (message[0]=='q') {
Close(clntSocket);
exit(0);
}

Note the single quotes around the q.

V
--
Please remove capital 'A's when replying by e-mail
I do not respond to top-posted replies, please don't ask

but if the message starts with q but has more characters after it?If I
compare only teh first charecter, it will not be appropriate.
Victor Bazarov wrote:
> Index wrote:
> > I am trying to compare a char* with an unsigned char*.I have type cast
> > the later to char*.Now the problem is, the unsigned char* is populated
> > with recv() function over the socket and sometimes it containes junk.I
> > need to compare the received message over the socket with a particular
> > charecter 'r' to terminate the entire process.
> > Any help will be highly appreciated.The code snippet and my output is
> > as follows:
> >
> > if(!(strcmp(message,"q"))){
> > Close(clntSocket);
> > exit(0);
> > }
> >
> > output screen:
> >
> > The received message is :q©
> >
> > Length of the received message 1
> > q©
> >
> > ** Though I typed q, the received message has a junk charecter at its
> > end and hence the comparison dosn't work.but sometimes after two/three
> > failed times, the string is without any junk charecter.
>
> You need to use 'strncmp' or simply compare the first character of
> the message:
>
> if (message[0]=='q') {
> Close(clntSocket);
> exit(0);
> }
>
> Note the single quotes around the q.
>
> V
> --
> Please remove capital 'A's when replying by e-mail
> I do not respond to top-posted replies, please don't ask

> Victor Bazarov wrote:
>> Index wrote:
[receiving data with recv, trying to compare with c-string]
>>> ** Though I typed q, the received message has a junk charecter at its
>>> end and hence the comparison dosn't work.but sometimes after two/three
>>> failed times, the string is without any junk charecter.
>> You need to use 'strncmp' or simply compare the first character of
>> the message:
>>
>> if (message[0]=='q') {
>> Close(clntSocket);
>> exit(0);
>> }
>>
>> Note the single quotes around the q.

Index wrote:
> but if the message starts with q but has more characters after it?If I
> compare only teh first charecter, it will not be appropriate.

Please don't top-post in this group. See the link in my signature.

The problem is, that you don't send/receive null-terminated strings. Either
null-terminate the received buffer before comparing, or compare with
strncmp and give as length parameter the number of received bytes.

--
Thomas
http://www.netmeister.org/news/learn2quote.html

Thanks.Its fixed.
Thomas J. Gritzan wrote:
> > Victor Bazarov wrote:
> >> Index wrote:
> [receiving data with recv, trying to compare with c-string]
> >>> ** Though I typed q, the received message has a junk charecter at its
> >>> end and hence the comparison dosn't work.but sometimes after two/three
> >>> failed times, the string is without any junk charecter.
> >> You need to use 'strncmp' or simply compare the first character of
> >> the message:
> >>
> >> if (message[0]=='q') {
> >> Close(clntSocket);
> >> exit(0);
> >> }
> >>
> >> Note the single quotes around the q.
>
> Index wrote:
> > but if the message starts with q but has more characters after it?If I
> > compare only teh first charecter, it will not be appropriate.
>
> Please don't top-post in this group. See the link in my signature.
>
> The problem is, that you don't send/receive null-terminated strings. Either
> null-terminate the received buffer before comparing, or compare with
> strncmp and give as length parameter the number of received bytes.
>
> --
> Thomas
> http://www.netmeister.org/news/learn2quote.html