rbenv help: fix 'type: write error: Broken pipe'

[FooBarWidget]

Sometimes the command fails with a 'type: write error: Broken pipe'. This is because 'head -1' only reads the first line, then exits. If 'type' writes the second line after 'head -1' has already exited, then the aforementioned error is triggered.

We fix this by buffering the entire output of 'type' before invoking 'head -1'.

[mislav]

Interesting, thank you! I've never came across this, but then again, I don't have gawk installed.

Which bash version do you have?

[mislav]

Could we try some less verbose approaches? e.g.

$(type -p gawk awk 2>/dev/null | head -1)

[FooBarWidget]

Redirecting all stderr to /dev/null would ignore all non-broken-pipe errors, so I don't think that's a good idea.

I'm not aware of any other way (besides foo=$(command)) to fully slurp the output of a command.

If you want shorter, I can change it into this:

  local all_awks
  all_awks=$(type -p gawk awk)

  # shellcheck disable=SC2016
  $(head -1 <<<"$all_awks") '

But imo that's not clearer.

[mislav]

Redirecting all stderr to /dev/null would ignore all non-broken-pipe errors, so I don't think that's a good idea.

That's true in general, but type -p doesn't output any useful errors in case the programs listed weren't found, so I found it acceptable to silence its stderr completely. Thank you!

[FooBarWidget]

It's the bash version that comes with Ubuntu 18.04, so 4.4.20. You can see the errors here:

• https://github.com/fullstaq-labs/fullstaq-rbenv/commit/362e522077bbaaa79842796a2d33e2301d552ed4/checks?check_suite_id=277180813
• https://github.com/fullstaq-labs/fullstaq-rbenv/commit/23393dc3f9129b41db0e0e7143850237400cc651/checks?check_suite_id=277171379