1#!/bin/bash 2 3# Copyright (c) 2008, Google Inc. 4# All rights reserved. 5# 6# Redistribution and use in source and binary forms, with or without 7# modification, are permitted provided that the following conditions are 8# met: 9# 10# * Redistributions of source code must retain the above copyright 11# notice, this list of conditions and the following disclaimer. 12# * Redistributions in binary form must reproduce the above 13# copyright notice, this list of conditions and the following disclaimer 14# in the documentation and/or other materials provided with the 15# distribution. 16# * Neither the name of Google Inc. nor the names of its 17# contributors may be used to endorse or promote products derived from 18# this software without specific prior written permission. 19# 20# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 21# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 22# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 23# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 24# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 25# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 26# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 27# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 28# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 29# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 30# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 31# 32# --- 33# Author: Dave Nicponski 34# 35# This script is invoked by bash in response to a matching compspec. When 36# this happens, bash calls this script using the command shown in the -C 37# block of the complete entry, but also appends 3 arguments. They are: 38# - The command being used for completion 39# - The word being completed 40# - The word preceding the completion word. 41# 42# Here's an example of how you might use this script: 43# $ complete -o bashdefault -o default -o nospace -C \ 44# '/usr/local/bin/gflags_completions.sh --tab_completion_columns $COLUMNS' \ 45# time env binary_name another_binary [...] 46 47# completion_word_index gets the index of the (N-1)th argument for 48# this command line. completion_word gets the actual argument from 49# this command line at the (N-1)th position 50completion_word_index="$(($# - 1))" 51completion_word="${!completion_word_index}" 52 53# TODO(user): Replace this once gflags_completions.cc has 54# a bool parameter indicating unambiguously to hijack the process for 55# completion purposes. 56if [ -z "$completion_word" ]; then 57 # Until an empty value for the completion word stops being misunderstood 58 # by binaries, don't actually execute the binary or the process 59 # won't be hijacked! 60 exit 0 61fi 62 63# binary_index gets the index of the command being completed (which bash 64# places in the (N-2)nd position. binary gets the actual command from 65# this command line at that (N-2)nd position 66binary_index="$(($# - 2))" 67binary="${!binary_index}" 68 69# For completions to be universal, we may have setup the compspec to 70# trigger on 'harmless pass-through' commands, like 'time' or 'env'. 71# If the command being completed is one of those two, we'll need to 72# identify the actual command being executed. To do this, we need 73# the actual command line that the <TAB> was pressed on. Bash helpfully 74# places this in the $COMP_LINE variable. 75if [ "$binary" == "time" ] || [ "$binary" == "env" ]; then 76 # we'll assume that the first 'argument' is actually the 77 # binary 78 79 80 # TODO(user): This is not perfect - the 'env' command, for instance, 81 # is allowed to have options between the 'env' and 'the command to 82 # be executed'. For example, consider: 83 # $ env FOO="bar" bin/do_something --help<TAB> 84 # In this case, we'll mistake the FOO="bar" portion as the binary. 85 # Perhaps we should continuing consuming leading words until we 86 # either run out of words, or find a word that is a valid file 87 # marked as executable. I can't think of any reason this wouldn't 88 # work. 89 90 # Break up the 'original command line' (not this script's command line, 91 # rather the one the <TAB> was pressed on) and find the second word. 92 parts=( ${COMP_LINE} ) 93 binary=${parts[1]} 94fi 95 96# Build the command line to use for completion. Basically it involves 97# passing through all the arguments given to this script (except the 3 98# that bash added), and appending a '--tab_completion_word "WORD"' to 99# the arguments. 100params="" 101for ((i=1; i<=$(($# - 3)); ++i)); do 102 params="$params \"${!i}\""; 103done 104params="$params --tab_completion_word \"$completion_word\"" 105 106# TODO(user): Perhaps stash the output in a temporary file somewhere 107# in /tmp, and only cat it to stdout if the command returned a success 108# code, to prevent false positives 109 110# If we think we have a reasonable command to execute, then execute it 111# and hope for the best. 112candidate=$(type -p "$binary") 113if [ ! -z "$candidate" ]; then 114 eval "$candidate 2>/dev/null $params" 115elif [ -f "$binary" ] && [ -x "$binary" ]; then 116 eval "$binary 2>/dev/null $params" 117fi 118