* Added support for shells without default variable support
* Added support for BusyBox installs that do not have `command` but has `which`
* Style fixes as suggested by reviewer
* Renamed `WHERE_IS` to `EXISTS` as suggested by review
* Removed expansion of `$LE_AUTO_SUDO` to `x` as the `-n` can check empty strings.
* Added `EXISTS` to debian bootstrap as suggested in review
* certbot-auto: Print link to doc on debugging pip install error
Also, update the doc to teach the user to workaround problem on a low
memory system.
* Correct formatting
* grep the PIP_OUT and print useful info if the problem is about memory allocation
* Fix logic on string to grep
Not resetting OPTIND between each call of getopts skips all short args except the first one.
It fixes this automated command:
./certbot-auto certonly --webroot -w /tmp -d example.com --agree-tos --email contact@example.com -n
Where "-w" was parsed by getopts and not "-n"
* When getopts is called multiple time we need to reset OPTIND. Issue #3459
* Adding OPTIND reset in the certbot-auto source file
* Building new letsencrypt-auto from template
I prefer to err toward simplicity here. Yes, there's an assumption necessary for this to work--that the shell doesn't do multiple open() calls to the script path throughout the life of the interpreter--but I think it's reasonable. The alternative of exec-ing out to a dedicated update script which then execs back to le-auto has more moving parts (like extra files that we have to clean up) and is longer.
Ported from #1751.
* It's more lines but fewer tokens, less room for quote errors, and more idiomatic (see any init.d script).
* Also, fix a bug in which any option containing "-v", e.g. --eat-vertical-pizza, would be construed as --verbose.
Ported from #1751.
* Make sure any Python passed in as $LE_PYTHON actually exists.
* Dodge a word-splitting bug: `a='a b'; export a=${a:-c}; echo $a` gives `a` instead of `a b` under shells that respect POSIX.1, like dash.
