Question

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

char* changeString(char *inputString);

int main() {
   printf("Changed string is %s\n", changeString("42"));
}

char* changeString(char *inputString) {
    static const char* someStrings[3] = {"abc", "def", "ghi"};
    char* output;
    strcat(output, someStrings[1]);
    return output;
}

I’m trying to append a char* to another char* however the strcat keeps resulting in a segmentation fault because the char* has no size, changing char* output; to char output[100]; fixes the segmentation fault, but then I am returning the wrong type and I can’t print the answer in printf.

Any advice would be much appreciated.

EDIT: I know the example above seems to do nothing of value, I changed it to demonstrate the logic I am using.

Answer 1

You have not allocated memory for the output string. Do use malloc() to allocate memory and then try strcat.