fscanf读取多个字符串

Question

So I am creating ac program that reads a query file filled with commands to execute on tables. So I used:

char command[100];
while(1)
{
    fscanf(query, "%s", command);
    x=strcmp(command, "select");
    //continue with checking for other commands etc.
    //if the command is stop then the loop breaks
}

My question is when I call fscanf the first time, I know it will save the command into the command array. But should I make the string "empty", or null as a better way to put it? I'm not sure if it's necessary when working with strcmp or in general with overwriting arrays with fscanf. Thank you!

Answer 1

You should not worry about something that is going to be overwritten. You should only ( always ) worry about initializing it before using its value . Because otherwise it is undefined behavior.

More importantly, you should always check the return value of functions operating on memory. You can never count on "that would work". Because after some time you would get Segmentation Fault out of the blue and won't know how to fix it.

In case you don't know how:

int check;

check = fscanf(query, "%s", command);
if(check == EOF)
    perror("fscanf");