Thread: Problem with string tokenizing

I'm trying to create a string tokenizing program. Here's what I got:

Code:

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

//Gets the number of tokens from a given string and delimiters
int getNumeroTokens(char* string,const char* delimitadores);

//Gets tokens from a string, saving them under a char**
char** stringTokenize(char* string,const char* delimitadores);

//Clones a string
char* stringClone(char* string);

//Gets a free position on a given array
int getPosicaoLivre(char** array,int array_length);

int main() {    
    char* string = malloc(BUFSIZ*sizeof(char));
    printf("String > ");
    fgets(string,BUFSIZ,stdin);
    
    char* delimitadores = malloc(BUFSIZ*sizeof(char));
    printf("Delimitadores > ");
    fgets(delimitadores,BUFSIZ,stdin);
    
    int n = getNumeroTokens(string,delimitadores);
    char** tokens = stringTokenize(string,delimitadores);
    
    int i;
    for (i=0;i<n;i++) printf("%s\n",tokens[i]);
    
    system("pause");
    return 0;
}

int getNumeroTokens(char* string,const char* delimitadores) {
    int ret=0;
    char* temp = stringClone(string);
    char* token_actual = strtok(temp,delimitadores);
    while (token_actual != NULL) {
          ret++;
          token_actual = strtok(NULL,delimitadores);
    }
    return ret;
}

char** stringTokenize(char* string,const char* delimitadores) {
    int i;
    int n = getNumeroTokens(string,delimitadores);
    printf("Debug\n");
    char** ret = malloc(n*sizeof(char*));
    printf("Debug\n");
    for (i=0;i<n;i++) ret[i]=NULL;
    char* temp = stringClone(string);
    char* token_actual = strtok(temp,delimitadores);
    while (token_actual != NULL) {
          int pos = getPosicaoLivre(ret,n);
          ret[pos]=stringClone(token_actual);
          token_actual = strtok(NULL,delimitadores);
    }
    return ret;
}

char* stringClone(char* string) {
    char* ret = malloc(sizeof(string));
    strcpy(ret,string);
    return ret;
}

int getPosicaoLivre(char** array,int array_length) {
    int i;
    for (i=0;i<array_length;i++) if (array[i]==NULL) return i;
    return -1;
}

So, basically, my program asks the user for a string, and then for its delimiters. Then, I get the tokens on a char** using my own stringTokenize function and finally print the obtained tokens.

Right. Now, if I compile my program, everything's OK. The problem is when I execute it.

If I input:
String > a-b
Delimiters > -

...it prints the tokens "a" and "b". OK. That's what I want in that case.

But if I input:
String > bananas/apples
Delimiters > /

...it fails here:

Code:

printf("Debug\n");
char** ret = malloc(n*sizeof(char*)); //<--- HERE
printf("Debug\n");

Please tell me what I'm doing wrong. Thank you in advance.

your stringClone() function is broken

Code:

char* stringClone(char* string) {
//    char* ret = malloc(sizeof(string));        // sizeof(string) is typically just 4 bytes
    char* ret = malloc(strlen(string)+1);       // length of string plus one for the terminating '\0'
    strcpy(ret,string);
    return ret;
}

Kurt

Wow. You're right. Thank you very much.

Are you suggesting I call the free() function upon my pointers?