Segmentation Error 11 in C file I / O

Question

I am writing a function that searches for a text file formatted as follows:

# User1 \ transfer
\
# User2 \ transfer \ # User3 \ transfer \

I wrote the Check_User function:

int Check_User(char input[20], FILE *userlist)
{
    int c, i;
    fseek(userlist, 0, SEEK_SET);
    while(1)
    {
        while((c = fgetc(userlist)) != '#')
        {
            if(c == EOF)
                return 1;
        }
        while(input[i] == (c = fgetc(userlist)))
        {
            i++;
        }
        i = 0;
        if(c == '\\')
            return 0;
    }
}

What is caused from here:

while(Check_User(username, userlist) == 0)
{
    printf("Username already in use. Please select another:");
    Get_Input(username);
}

Verify that the user checks the file pointed to by * userlist to see if the username [20] contains a username that is already in use. If it is already in use, it calls Get_Input for the new username.

The program paves the way to the while loop, and then gives me a segmentation error: 11. I read that this is often associated with trying to write outside the array or even do something in memory, I don’t have access. Userlist.txt was opened in r + mode.

Thanks for the help.

Answer 1

i . C 0 ( # Java), , . , i , input, input[i] .

: Linux, (gcc -g), valgrind --tool=memcheck <your program>, valgrind .