Redirecting input from gdb file

I cannot get gdb to redirect the file to the stdin of my program.

Outside, gdb ./prog.x < someinput.txt

does exactly what I want.

Inside gdb, when I run it (gdb) run < someinput.txt

, my program doesn't seem to "see" the input file, but instead stdin seems to read what I enter into the console.

(gdb) run < testinput.txt
Starting program: /Users/alexpatch/Documents/krc/misc/sandbox.x < testinput.txt
[New Thread 0x1603 of process 8308]

      

        
        
        
      

    

My cursor appears on a blank line below this where I can type text. Cd exits this, then prints the output of the program with what I just typed and the process exits normally.

/* trivial code example */

#include <stdio.h>

int main(void)
{
  int c;

  while ((c = getchar()) != EOF)
    putchar(c);

  return 0;
}

      

        
        
        
      

    

I found several answers related to similar problems, but the solution that seemed to work for them was what I'm already doing, namely (gdb) run < someinput.txt

. In case this is helpful, I am working on a 64-bit MacBook Air running macOS Sierra.