implement strtok

Question

implement strtok

Nomad · Accepted Answer

char * my_strtok(char * str, char *token) {
  static char *buffer;
  
  if(str != NULL)
  	buffer = str;
  	
  if(buffer == NULL)
  	return NULL;
  	
  char * res = buffer;
  char *b, *d; 
  
  for (b = buffer; *b!= '\0'; b++) {
  	for (b= token; *d != '\0'; d++){
  		if(*b==*d){
  			*b = '\0'
  			b = b+1;
  			
  			// skip if the match is the start 
  			if(res == b){
  				res++;
  				continue;
  			}
  		 return res;
  		}
  	}
  	
  }
  return res;
}

Lawler · Answer

Here is a more elegant and easier to understand solution in my opinion. 

char * strtoken(char * string, char * delim) {
	static char * lastToken = NULL;

	/* Set string to the last saved state when the user passes NULL */
	if(string == NULL)
		string = lastToken;

	/* We done boys, pack your bags. */
	if(lastToken == NULL)
		return NULL;

	/* Find every character in delim and replace every instance of those in string with a \0 */
	for(int i = 0; i < strlen(string); i++) {
		for(int j = 0; j < strlen(delim); j++) {
			if(string[i] == delim[j]) {
				string[i] = '\0';
			}
		}
	}

	/* Increment our save pointer with the length of the last string */
	lastToken += strlen(string);
	return string;
}

Lawler · Answer

Fixed a few bugs from before:

char * strtoken(char * string, char * delim) {
	static char * lastToken = NULL;

	/* Set string to the last saved state when the user passes NULL */
	if(string == NULL) 
		string = lastToken;

	/* We done boys, pack your bags. */
	if(string == NULL)
		return NULL;

	/* Find every character in delim and replace every instance of those in string with a \0 */
	for(int i = 0; i < strlen(string); i++) {
		for(int j = 0; j < strlen(delim); j++) {
			if(string[i] == delim[j]) {
				string[i] = '\0';
				/* Remove extra delimeters*/
				if(!strcmp(string,"")) string = strtoken(string + 1, delim);
				/* Increment our save pointer starting at the index after the \0 */
				lastToken = strchr(string, '\0') + 1;
				return string;
			}
		}
	}

	/* No more tokens, let's get out of here */
	lastToken = NULL;
	if(!strcmp(string,"")) return NULL;
	return string;
}

manju · Answer

one are more if  condition is used.  first condition is string (str)  then second condition is buffer  is not correct.

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