In trying to get a collectd instance to send me alerts, I found out that I didn’t know how to just read everything that might be piped into a bash script via standard input. You can read line by line easily using the
read command. Just looping over it seemed pretty horrendous to me until I discovered an elegant way to do it that’s perhaps canonical, but doesn’t seem to pop up via quick googling:
#!/bin/bash VALUE=$(cat) echo "$VALUE"
$(cat) is a shorthand for
$(cat /dev/stdin), so presumably you can use this to read from stderr by pointing it at