Thread: question about function strcmp() in C

There is partial code in C

Code:

typedef struct message {
    int messageId;
    char *messageText;
    struct message *next;
}message;
.....
.....
.....
/* Get a node before a node */
message *nodeBefore ( message *text ) {
    message *tem;
    tem = head;
    /* If there are only 2 nodes ( a and b ),then nodeBeforeByText of a is returning to a */
184:if ( strcmp(tem->messageText,text) == 0)
           return tem;
       else {
           while ( tem  != NULL ) {	    
188:         if ( strcmp(tem->next->messageText,text) == 0 )            
                    break;        
             else
                    tem = tem->next;
          }
       }
       return tem;   
}

When I compiled there were messages :

Code:

q2.c:184: warning: passing arg 2 of `strcmp' from incompatible pointer type
q2.c:188: warning: passing arg 2 of `strcmp' from incompatible pointer type

After looking up the reference for strcmp() in library, I still dont understand why there are messages here.Can some body explain to me.

Maybe take a closer look at the definition of struct message, a pointer of which is your variable named 'text', and find a string from there to give to strcmp.

The correct answer depends on the call to

Code:

message *nodeBefore ( message *text )

- does it call with a message or a char *?

--
Mats

I'd suggest you stop calling everything message, it's confusing