Working with Strings C, Reading and Writing strings

Question

This is part of my code. My program reads a .txt and analyzes the instructions written in the text to perform the actions.

char *insertar(char line[1024],int num)
{
    int i=9;
    int pos=0;
    char c;
    while(i<strlen(line))
    {
        c=line[i];
        switch(pos){
            case 0:
                if((c[0]!=',')||(c[0]!=')'))
                {
                    strcat(reg[num].codigo,c);
                }
                else{
                    pos++;
                }
                break;
            case 1:
                if((c[0]!=',')||(c[0]!=')'))
                {
                    strcat(reg[num].placa,c);
                }
                else{
                    pos++;
                }               
                break;
            case 2:
                if((c[0]!=',')||(c[0]!=')'))
                {
                    strcat(reg[num].year,c);
                }
                else{
                    pos++;
                }               
                break;
            case 3:
                if((c[0]!=',')||(c[0]!=')'))
                {
                    strcat(reg[num].tipo,c);
                }
                else{
                    pos++;
                }               
                break;
            case 4:
                if((c[0]!=',')||(c[0]!=')'))
                {
                    strcat(reg[num].marca,c);
                }
                else{
                    pos++;
                }               
                break;
            default:
                reg[num].estado=1;
                return 0;
                break;
        }       
    i++:
    }
    fwrite();
}

The problem is that in every line where this lies

strcat(reg[num].codigo,c);

I get this error:

error: invalid conversion from 'char' to 'const char*' [-fpermissive]

How can I fix it?

Answer 1

signature of strcat is char * strcat ( char * destination, const char * source );

in your code second parameter is char c, hence the issue

Answer 2

The signature of strcat is char *strcat(char*, char*), but you're passing a char as the second argument. The second argument needs to be a pointer to a char... i.e. &c... but that's not the whole solution... There are other issues here- all the c[0] are incorrect, because c is not an array of char. I think in most of these cases you just mean c.