Question

I want to store strings in a binary file, along with a lot of other data, im using the code below (when i use it for real the strings will be malloc’d) I can write to the file. Ive looked at it in a hex editor. Im not sure im writing the null terminator correctly (or if i need to). when i read back out i get the same string length that i stored, but not the string. what am i doing wrong?

FILE *fp = fopen("mybinfile.ttt", "wb");

char drumCString[6] = "Hello\0";
printf("%s\n", drumCString);    
//the string length + 1 for the null terminator
unsigned short sizeOfString = strlen(drumCString) + 1;
fwrite(&sizeOfString, sizeof(unsigned short), 1, fp);

//write the string
fwrite(drumCString, sizeof(char), sizeOfString, fp);

fclose(fp);

fp = fopen("mybinfile.ttt", "rb");  

unsigned short stringLength = 0;
fread(&stringLength, sizeof(unsigned short), 1, fp);

char *drumReadString = malloc(sizeof(char) * stringLength);
int count = fread(&drumReadString, sizeof(char), stringLength, fp);

//CRASH POINT
printf("%s\n", drumReadString);

fclose(fp); 

Answer 1

You are doing wrong while reading.
you have put the & for the pointer variable that’s why it gives segmentation fault.

I removed that it works fine and it returns Hello correctly.

int count = fread(drumReadString, sizeof(char), stringLength, fp);