How do I read until the end of file?

In C, I can read an input and stop the program when it reaches the end of file (EOF). Like so.

#include <stdio.h>

int main(void) {
    int a;       
    while (scanf("%d", &a) != EOF)
        printf("%d\n", a);
    return 0;
}

How can I do that in Lua?

The Lua Documentation features a ton of details on file-reading and other IO. For reading an entire file use:

t = io.read("*all")

The documentation has examples on reading line-by-line etc. Hope this helps.

Example on reading all lines of a file and numbering each of them (line-by-line):

   local count = 1
    while true do
      local line = io.read()
      if line == nil then break end
      io.write(string.format("%6d  ", count), line, "\n")
      count = count + 1
    end