Question

This is my code:

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

void getinfo(unsigned int a, unsigned int b, char **s);

int main(){
    unsigned int len_max = 8;
    unsigned int current_size = 0;
    char *pStr = malloc(len_max);
    if(pStr == NULL){
        perror("\nMemory allocation\n");
        return EXIT_FAILURE;
    }
    current_size = len_max;

    printf("Inserisci hostname: ");
    getinfo(len_max, current_size, &pStr);
    printf("\nLa stringa inserita è: %s\n", pStr);
    free(pStr);
    return EXIT_SUCCESS;
}

void getinfo(unsigned int a, unsigned int b, char **pStr){
    unsigned int i = 0;
    char c = EOF;
    while((c = getchar()) != '\n'){
        *pStr[i++] = (char)c;
        if(i == b){
            b = i+a;
            if((*pStr = realloc(*pStr, b)) == NULL){
                perror("\nMemory allocation error\n");
                exit(EXIT_FAILURE);
            }
        }
    }
    *pStr[i]='\0';
}

When i execute this code i got a segmentation fault when i press enter (after i’ve wrote the string).
I’m sure the problem is into the function (probably the problem is the *s pointer) but i don’t know how to correct it…

Answer 1

You have a precedence problem. You need to use

(*s)[i++] = ...

instead of

*s[i++] = ...

Similarly you need

(*s)[i]='\0';

When you write *s[i] you are indexing s. But you want to index *s, and hence require the parentheses.

I’ve not checked the rest of your code, but I hope this helps you on your way to debugging the rest of it, if indeed there are more errors.