How to correctly pipe output into "say" in terminal

Based on mankoff's answer, this works:

leave +1 2>&1 | while read line ; do echo $line | say ; done

although leave no longer vanishes into the background and lets you carry on typing. Similarly:

leave +1 2>&1 | while read line ; do echo $line | say ; done &

will make it vanish into the background, but will also speak a (harmless) process ID number as well. So neither is quite perfect, but both work.

(I was looking for a solution to:

ping google.com | say

which suffers a similar problem, and someone suggested the above as a solution. I didn't add this as a comment to mankoff's answer because I can't work out how to put spaces and newlines in comments.).

Your example is, in general, the correct way to pipe normal output to say:

 cat file | say
 echo "hello world" | say

The specific issue is that the | (pipe) character transfers STDOUT from the command on the left to STDIN to the command on the right. say then speaks whatever is on STDIN.

However, leave does not print the output directly to STDOUT. It is either using STDERR, or some other message mechanism. You can pipe STDERR through the |, but the syntax is shell dependent. For bash, you would do it like so, although I'm not sure that this will make leave work with say, as I don't much about leave.

cmd 2>&1 |cmd2

As an addition to this - if you want to pipe an ongoing file to say, the "recipe" also works with tail:

tail -f ~/Documents/activity.log | while read line ; do echo $line | say ; done