guozheng / howdoi

instant coding answers via the command line

howdoi

instant coding answers via the command line

Are you a hack programmer? Do you find yourself constantly Googling for how to do basic programing tasks?

Suppose you want to know how to format a date in bash. Why open your browser and read through blogs (risking major distraction) when you can simply stay in the console and ask howdoi:

$ howdoi format date bash
> DATE=`date +%Y-%m-%d`

howdoi will answer all sorts of queries:

$ howdoi print stack trace python
> import traceback
>
> try:
>     1/0
> except:
>     print '>>> traceback <<<'
>     traceback.print_exc()
>     print '>>> end of traceback <<<'
> traceback.print_exc()

$ howdoi convert mp4 to animated gif
> video=/path/to/video.avi
> outdir=/path/to/output.gif
> mplayer "$video" \
>         -ao null \
>         -ss "00:01:00" \  # starting point
>         -endpos 10 \ # duration in second
>         -vo gif89a:fps=13:output=$outdir \
>         -vf scale=240:180

$ howdoi create tar archive
> tar -cf backup.tar --exclude "www/subf3" www

Installation

pip install howdoi

or

pip install git+https://github.com/gleitz/howdoi.git#egg=howdoi

or

brew install https://raw.github.com/gleitz/howdoi/master/howdoi.rb

or

python setup.py install

Usage

usage: howdoi.py [-h] [-p POS] [-a] [-l] [-c] [-n NUM_ANSWERS] [-C] [-v] QUERY [QUERY ...]

instant coding answers via the command line

positional arguments:
  QUERY                 the question to answer

optional arguments:
  -h, --help            show this help message and exit
  -p POS, --pos POS     select answer in specified position (default: 1)
  -a, --all             display the full text of the answer
  -l, --link            display only the answer link
  -c, --color           enable colorized output
  -n NUM_ANSWERS, --num-answers NUM_ANSWERS
                        number of answers to return
  -C, --clear-cache     clear the cache
  -v, --version         displays the current version of howdoi

Author

• Benjamin Gleitzman (@gleitz)

Notes

• Works with Python2 and Python3
• A standalone Windows executable with the howdoi application is available here.
• An Alfred Workflow for howdoi can be found at http://blog.gleitzman.com/post/48539944559/howdoi-alfred-even-more-instant-answers.
• Slack integration available through slack-howdoi.
• Howdoi uses a cache for faster access to previous questions. Caching functionality can be disabled by setting the HOWDOI_DISABLE_CACHE environment variable. The cache is stored in ~/.cache/howdoi.
• You can set the HOWDOI_URL environment variable to change the source url for answers (default: stackoverflow.com). Other options include serverfault.com or pt.stackoverflow.com. Here's the full list.
• Setting the HOWDOI_COLORIZE environment variable will colorize the output by default.
• Special thanks to Rich Jones (@miserlou) for the idea.

Development

• Checkout the repo
• Run python -m howdoi.howdoi QUERY (if you try running python howdoi/howdoi.py you my get ValueError: Attempted relative import in non-package).

Troubleshooting

You might get the following error when installing with Homebrew:

==> python setup.py install

http://peak.telecommunity.com/EasyInstall.html

Please make the appropriate changes for your system and try again.

Fix the error by executing the following command:

sudo chmod -R go+w /Library/Python/2.7/site-packages/

An official lxml for python 3.3+ for windows has not yet been released. You may get an error while installing. Try and install an unofficial binary for lxml from

http://www.lfd.uci.edu/~gohlke/pythonlibs/#lxml