What is wrong with my strcmp function? - c

Question

My code is:
getline(&cmd, &len, stdin);
cmd[strcspn(cmd,"\n")] = 0;
char *ncmd = (char*)malloc(strlen(cmd) + 1);
memset(ncmd, '\0', strlen(cmd));
strcpy(ncmd,cmd);
const char *tok = strtok(ncmd, " ");
// token is just string from stdin
if(!strcmp(tok, "bye")){
printf("bye");
} else if (!strcmp(tok, "help")){
printf("help");
} else if (!strcmp(tok, "list")){
......
}
ie. For input: help and bye
Result: TOK: help
strcmp(tok, "bye"): 6
strcmp(tok, "help"): 0
strcmp(tok, "list"): -10
Result: TOK: bye
strcmp(tok, "bye"): 0
strcmp(tok, "help"): -6
strcmp(tok, "list"): -4
Whatever I type, I can't seem to pull out the correct if statement.
How do I fix the "strcmp" function so it goes to the correct if statements?

Answer 1

As the code and if statement are correct, I think tok has extra characters, such as a newline. Then tok will never be equal to any of your words.

Answer 2

When creating a buffer to use with strtok(), often times the same buffer will be used several times. Therefore, instead of declaring it as:
const char *tok = strtok(ncmd, " "); //tok cannot be changed (const keyword)
Create it so it can be changed:
char *tok = strtok(ncmd, " ");//tok can be changed (removed const keyword)
Example:
char string[] = {"this is \n a string \t with embedded \r non-printables"};
char *tok = {0}; //declare and initialize
tok = strtok(string, " \n\r\t");
while(tok)
{
tok = strtok(NULL, " \n\r\t");//tok will be a different value each iteration
// 1 - this
// 2 - is
// 3 - a
// 4 - string
// and so on
}
...

Answer 3

I didn't understand your code properly, but I hope this is what you are trying to achieve in your code:
int main()
{
char list[] = "bye help list";
char *delim = " ";
char *pch = strtok(list,delim);
int count = 0;
while(pch) {
if(!strcmp(pch,"bye")) {
printf("i found bye at %d\n",count);
} else if (!strcmp(pch,"help")) {
printf("i found help at %d\n",count);
} else if (!strcmp(pch,"list")) {
printf("i found list at %d",count);
}
count++;
pch = strtok(NULL,delim);
}
printf("\n");
return 0;
}