pipevcr

Record and play back pipes. Similar to what script does with the terminal but for pipes.

This can be used for debugging or testing where timing matters.

Installation

pip3 install --user pipevcr

# or if you have pipx
pipx install pipevcr

Usage

usage: pipevcr [-h] [-r] [-s SPEED] [-m MAX_PAUSE] FILE

pipevcr - the linux pipe recorder

positional arguments:
  FILE                  data file

options:
  -h, --help            show this help message and exit
  -r, --record          record pipe
  -s SPEED, --speed SPEED
                        playback speed, <1 to slow down, >1 to speed up
  -m MAX_PAUSE, --max-pause MAX_PAUSE
                        max pause time between outputs in seconds

Record

You record a pipe with -r, e.g.:

(echo wait 1; sleep 1; echo wait 2; sleep 2; echo end) | pipevcr -r test.vcr

Playback

And play it back with:

pipevcr test.vcr

Faster

To speed it up (2=double):

pipevcr -s 2 test.vcr

Slower

To slow it down (.5=half):

pipevcr -s .5 test.vcr

You can also set the maximum pause time separately:

pipevcr -m 1 test.vcr