Mercurial > hg > mhoward > dotfiles / file revision

#!/usr/bin/env ruby

# Meant for use as a git hook:
#   CTAGS_HOOK=1 ~/.git_helpers/ctags &>/dev/null </dev/null &
# or an aliased cmd on demand:
#   git config alias.ctags '!.git/hooks/ctags'
# or disable when you wish:
#   CTAGS_SKIP=1 git rebase

# Create a tags file (target) using git's list of tracked files.  If
# .git/ctags.conf exists in the repo it is passed to the ctags invocation.
#
# When run w/o env, immediately run ctags and replace tags file.
#
# When run with CTAGS_HOOK, it's assumed to be a BG process and we want to wait
# for git to be done applying changes no matter how the hook is triggered.
# Wait five seconds, then bail if we can't get a lock on the tags file or if
# it's been updated within the last minute. Only then, run ctags and replace
# the tags file.

exit if ENV['CTAGS_SKIP']

ctags  = 'ctags'

dir    = `git rev-parse --show-toplevel`.chomp

conf   = "#{dir}/.git/ctags.conf"
target = "#{dir}/.tags"
tmp    = "#{dir}/.tags.#{$$}~"

opts   = File.exists?(conf) ? "--options=#{conf}" : ''

sleep 5 if ENV['CTAGS_HOOK']

open(target, File::RDONLY|File::CREAT, 0644) do |f|
  if ENV['CTAGS_HOOK']
    exit unless f.flock(File::LOCK_EX|File::LOCK_NB)
    exit unless (Time.now - f.mtime) > 60
  end

  system(<<-CMD) or exit $?.exitstatus
    git ls-files \
     | #{ctags} --tag-relative -L - -f"#{tmp}" #{opts} \
    && mv #{tmp} #{target}
  CMD
end