Thread: strcmp() not returning 0 when its suppose to

well i am trying to store it into a buffer, however I am finding troubles getting the buffer to work:

here's a sample of what I have going on now:

Code:

char msgBuf ="NULL";

	while( (num = read(0,message,sizeof(message))) > 0){
		
		
		

		if(strcmp(message, "exit\n") == 0){
			printf("Exiting . . .\n");
  			/* Close this connection. */
			pthread_join(root, &temp);
  			close(sock);
			exit(0);
		}
		
					
		//printf("EOM CHECK WITH %s, %d \n", message, strcmp(message,"EOM\n"));

		
		if(strcmp(message, "SEND\n") == 0){
			printf("SEND DOES = 0\n");
			if(send(sock,msgBuf,1024,0) < 0){
			pdie("Writing on stream socket");
			}
		}else{
			strcat(msgBuf,message);
			printf("Sizeof msgBuf %d\n", sizeof(msgBuf));
			//strcat(msgBuf, message);
			printf("msgBuf:\n %s", msgBuf);		
		}

If "SEND" is not the first input then it never works, thus always "strcat" the string. And then random things seem to start showing up:

Sizeof msgBuf 5
msgBuf:
Nullhi there
what going on
do you smell anything
SEND
ou mell anything

I have no idea where "ou smell anything" is coming from

hm i see.

Also i was wondering:

since (in my case) read() is storing what it reads into message[] do i flush message[] by simply

Code:

message[0] = 0;

I'm beginning to see the problem that message[] is getting written in to way to much

hi there //input from command line
Message len 9
total = 9
go //input from command line
Message len 9
total = 18

how would i reset message[]?

Originally Posted by quzah

You don't need to reset the message. You need to be making your strings nul-terminated. I suppose if you don't like that, and want to do it the more expensive way, you could call memset on it. But again, you really just need to treat your strings right.


Quzah.

Sorry, I need clarification:

to nul-terminate my strings i would add a '\0' at the end of message[] at every read. But how would that make a difference?

Code:

while( (num = read(0,message,sizeof(message))) > 0)

           message[strlen(message)++] = '\0';

Originally Posted by TaiL

Sorry, I need clarification:

to nul-terminate my strings i would add a '\0' at the end of message[] at every read. But how would that make a difference?

Code:

while( (num = read(0,message,sizeof(message))) > 0)

           message[strlen(message)++] = '\0';

Because in C, char's without an end of string char to elevate them, are just a collection of char's - and not a string.

You can't expect standard C string functions to work on them.

bunch of char's: ABCDEFGH

string: ABCDEFGH'\0'

Which many functions in C will make for you: fgets(), for one.

Tail, strlen() makes no sense, when used on something that is *NOT* a string.

Doesn't compute.