It's well known how to pipe the standard ouput of a process into another processes standard input:
proc1 | proc2
But what if I want to send the standard error of proc1 to proc2 and leave the standard output going to its current location? You would think bash would have a command along the lines of:
proc1 2| proc2
But, alas, no. Is there any way to do this?
There is also process substitution. Which makes a process substitute for a file.
You can send stderr to a file as follows:
process1 2> file
But you can substitute a process for the file as follows:
process1 2> >(process2)
Here is a concrete example that sends stderr to both the screen and appends to a logfile
sh myscript 2> >(tee -a errlog)
None of these really worked very well. The best way I found do do what you wanted is:
(command < input > output) 2>&1 | less
This only works for cases where command does not need keyboard input. eg:
(gzip -d < file.gz > file) 2>&1 | less
would put gzip errors into less