redirect-file-to-stdin-during-delve-debug.md

Redirect File To Stdin During Delve Debug

I have a go program that accepts input from stdin. The way I've been running the program as I develop it is to redirect the output of some sample files to the program.

$ go run . < sample/001.txt

When I then go to debug this program with Delve, I'd still like to be able to redirect a file into the program to reproduce the exact behavior I'm seeing.

The following won't work:

$ dlv debug . < samples/001.txt
Stdin is not a terminal, use '-r' to specify redirects for the target process or --allow-non-terminal-interactive=true if you really want to specify a redirect for Delve

Fortunately, dlv sees what I'm trying to do and makes a recommendation. The -r flag can be used to specify redirects for the target process. The dlv redirect docs explain that -r can be passed a source:destination. The source is stdin by default, but can also be stdout and stderr.

I can redirect my file into the debugging session of my program like so:

$ dlv debug . -r stdin:samples/001.txt

Or even more succinctly:

$ dlv debug . -r samples/001.txt