Create ctags for the current virtualend or buildout

buildout-tags.sh

#!/bin/bash
# Build a vim tags file for all the Python packages in the buildout path
# Assumes . is the directory with a buildout.cfg
# Note: there is no one true buildout path -- every part has its own.  So
# we look for a python interpreter in bin/python (or bin/py) and use its path.
# If that fails, we try to find a bin/test script and scrape the path from it.
# Should also work with virtualenv (just run it somewhere with a bin/python)
# Published at https://gist.github.com/mgedmin/5152189

progname=${0##*/}

die() {
    echo "$progname: $@" 1>&2
    exit 1
}

verbose=0
dry_run=0
system_python=0
scriptname=

for arg; do
    case "$arg" in
        -h|--help)
            echo "Usage: $progname [-v|--verbose] [-n|--dry-run] [-s|--system-python] [buildout-generated-script-filename]"
            exit 0
            ;;
        -v|--verbose)
            verbose=1
            ;;
        -n|--dry-run)
            dry_run=1
            ;;
        -s|--system-python)
            system_python=1
            ;;
        -*)
            die "Unexpected argument: $arg"
            ;;
        *)
            if [ -z "$scriptname" ]; then
                scriptname=$arg
            else
                die "Unexpected argument: $arg"
            fi
            ;;
    esac
done

extra_work=
if [ -n "$scriptname" ] && [ -x "$scriptname" ]; then
    shebang=$(head -n 1 "$scriptname")
    python=${shebang:2}
    extra_work="exec(open('$scriptname').read(), {});"
elif [ $system_python -ne 0 ]; then
    python=python
elif [ -x bin/python ]; then
    python=bin/python
elif [ -x bin/py ]; then
    # some zope.foo buildouts use interpreter = bin/py
    python=bin/py
elif [ -x .venv/bin/python ]; then
    python=.venv/bin/python
elif [ -x .env/bin/python ]; then
    python=.env/bin/python
elif [ -x env/bin/python ]; then
    python=env/bin/python
elif [ -x bin/test ]; then
    shebang=$(head -n 1 bin/test)
    python=${shebang:2}
    extra_work="exec(open('bin/test').read(), {});"
else
    die "I expect to find a bin/python (or bin/py, or bin/test) here"
fi
paths=$($python -c "
import os, sys
${extra_work}
d = set(p for p in sys.path if os.path.isdir(p) and not os.path.isdir(os.path.join(p, 'dist-packages')))
for p in sys.path:
    if os.path.isdir(os.path.join(p, 'dist-packages')):
        d.add(os.path.join(p, '*.py'))
        for s in os.listdir(p):
            if os.path.exists(os.path.join(p, s, '__init__.py')):
                d.add(os.path.join(p, s))
print('\\n'.join(sorted(d)))
")
test -n "$paths" || die "The python path is empty?  Confused."
test $verbose -ne 0 && echo "$paths"
if [ $dry_run -eq 0 ]; then
    ctags-exuberant -R -f .tags.new $paths && mv .tags.new tags || rm .tags.new
fi