How to debug executable (using gdb) that reads another file?

Question

I have a small application let's call it program. In general to use this application I need to stream a file into it:

./program < file_with_data.txt

How do I debug such program using dbg? I don't know how to pass data from file to program when it is controlled by dbg.

Answer 1

Found it:after running:

gdb program

write

run < file_with_data.txt