Have you ever wanted to stop and edit text in the middle of a pipeline? With vipe you can!

Take the output of brew search as an example.

$ brew search proxy
==> Formulae
aws-es-proxy                  metaproxy                     proxytunnel
dnscrypt-proxy                mitmproxy                     sproxy
haproxy                       oauth2_proxy                  tinyproxy
ios-webkit-debug-proxy        ocproxy                       twemproxy
libproxy                      proxychains-ng

==> Casks
proxyman

What we if want to call brew info to get more details for those formulae?

Even if we pipe the output to something (e.g. cat) we still have the Formulae and Casks headers:

$ brew search proxy | cat
==> Formulae
aws-es-proxy
dnscrypt-proxy
haproxy
ios-webkit-debug-proxy
libproxy
metaproxy
mitmproxy
oauth2_proxy
ocproxy
proxychains-ng
proxytunnel
sproxy
tinyproxy
twemproxy

==> Casks
proxyman

We could write some intermediate steps to remove the lines we don’t want. But wouldn’t it be great to have our pipeline stop, let us edit the stream, and then continue?

$ brew search proxy | magic | while read formula; do brew info $formula; done

It turns out that vipe can be that magic! It will stop and give you a vim session with the output of the preceeding pipe. When you write/quit the vim session that output will be sent down to the subsequent commands in the pipe. Awesome!

Installing vipe

You can get vipe on OSX as part of the moreutils brew formula.

$ brew install moreutils

Usage

Then drop it in wherever you want to quickly edit text in the middle of the pipeline. It’s also great as a nice way to view intermediate output of a pipeline.

$ brew search proxy | vipe | while read formula; do
  brew info "$formula";
done

When we run that command the brew search proxy output goes straight into a vim buffer.

 1 ==> Formulae
 2 aws-es-proxy
 3 dnscrypt-proxy
 4 haproxy
 5 ios-webkit-debug-proxy
 6 libproxy
 7 metaproxy
 8 mitmproxy
 9 oauth2_proxy
10 ocproxy
11 proxychains-ng
12 proxytunnel
13 sproxy
14 tinyproxy
15 twemproxy
16
17 ==> Casks
18 proxyman

vim editing goodness We can manipulate that buffer to be whatever we want.

1 mitmproxy

How about we trim down to one interesting formula? When we save and quit the pipeline continues into the while read loop that sends all the input to brew info.

"/private/var/folders/n6/gxxgmjhs1599x195xzdbnp_40000gn/T/mL0nDL6bCD" 1L, 10C written

mitmproxy: stable 4.0.4 (bottled), HEAD
Intercept, modify, replay, save HTTP/S traffic
https://mitmproxy.org
Not installed
From: https://github.com/Homebrew/homebrew-core/blob/master/Formula/mitmproxy.rb
==> Dependencies
Required: openssl@1.1 ✔, protobuf ✘, python ✘
==> Options
--HEAD
    Install HEAD version
==> Analytics
install: 6,017 (30 days), 15,281 (90 days), 46,094 (365 days)
install_on_request: 5,777 (30 days), 14,445 (90 days), 44,138 (365 days)
build_error: 0 (30 days)

Nice!