Dumping generated output so far, upon request

[farzadghanei]

mute captures the output until the sub command exits. For long running sub commands, it could be helpful to see the output upon request.

One request approach is to use signals. possible solutions to provide the output is stdout or a temp file (or both). So it could be that upon a signal (USR1?) mute prints the buffered output to stdout, and upon another signal (USR2?) creates a temp file whose contents are the generated output so far.

Regarding the temp file:

• filename should be unique. Could use command name, pid, timestamp, +rand
• consider security and file access