Help! strcmp is lying to me when fed strtok results.

Question

Hey Folks,

strcmp, when fed the results of strtok, in the following code seems to be blatantly lying to me.

int fSize;
char * buffer=NULL;
char * jobToken = "job";
char * nextToken=NULL;
job * curJob=NULL;
struct node * head=NULL;
struct node * parseList(FILE* file){
    fseek(file,0,SEEK_END);
    fSize=ftell(file);
    buffer = (char*)malloc(fSize+1);
    printf("%d chars: reading buffer now:\n",fSize);
    fseek(file,0,SEEK_SET);
    fread (buffer,1,fSize,file);
    nextToken = strtok(buffer, " \n");
    while (nextToken!=NULL){
            printf("**Running  Token: %s**\n",nextToken);
            if (strcmp(nextToken,jobToken)){
                    printf("Accepted %s  as %s\n",nextToken,jobToken);                
            }else{
                    printf("not %s, %s\n",jobToken,nextToken);
            }

            printf("End of state - %s\n",nextToken);

            nextToken = strtok(NULL, " \n");
    }
    free (buffer);
    return NULL;
}

With this input in a file in the parseList parameters:

job 23
job 10

Gives this output:

14 chars: reading buffer now:
**Running  Token: job**
not job, job
End of state - job
**Running  Token: 23**
Accepted 23  as job
End of state - 23
**Running  Token: job**
not job, job
End of state - job
**Running  Token: 10**
Accepted 10  as job
End of state - 10

LIES!

Answer 1

strcmp returns 0 when the strings you are comparing are equal. You need to use if (!strcmp(...)).

Answer 2

strcmp returns 0 when the strings are equal. See: http://www.elook.org/programming/c/strcmp.html

Answer 3

Not related to your question, but a couple of points:

• After the fread(), you should set buffer[fSize] = 0;, otherwise it's not a string.
• Determining the numbers of characters to read in either a text file or a binary file using fseek(file,0,SEEK_END); isn't guaranteed to work.

Personally, I would write the malloc() call as:

buffer = malloc(fSize+1);

because that will warn me if I forgot to #include <stdlib.h>, and is easier to read. The cast is not required in C.