* Don't bother reading empty version files
* Implement version file read in pure bash
Is faster with usual sized version files, slower with degenerate cases.
Sometimes it is convenient to be able to temporarily disable something
in a version-file. Because these files often aren't necessarily tracked
in a SCM, especially when working with virtualenvs, the SCM diffs won't
help with showing removed lines which are currently the only way to
disable something.
All scripts in libexec/ (excluding pyenv) are called through pyenv,
therefore the shebang lines are not necessary. On some systems this
provides a measurable increase in performance of the shell prompt.
Related to pyenv/pyenv-virtualenv#259
I was seeing the following occasionally in scripts:
> …/.pyenv/libexec/pyenv-version-file-read: line 12: type: write error: Broken pipe
This patch hopefully improves/fixes this, and it seems better anyway to
just use sed here.
