WTF NPAPI extension. Early draft.

tools/nixysa/third_party/gflags-1.0/src/gflags_completions.sh

+#!/bin/bash
+
+# Copyright (c) 2008, Google Inc.
+# All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are
+# met:
+#
+#     * Redistributions of source code must retain the above copyright
+# notice, this list of conditions and the following disclaimer.
+#     * Redistributions in binary form must reproduce the above
+# copyright notice, this list of conditions and the following disclaimer
+# in the documentation and/or other materials provided with the
+# distribution.
+#     * Neither the name of Google Inc. nor the names of its
+# contributors may be used to endorse or promote products derived from
+# this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+#
+# ---
+# Author: Dave Nicponski
+#
+# This script is invoked by bash in response to a matching compspec.  When
+# this happens, bash calls this script using the command shown in the -C
+# block of the complete entry, but also appends 3 arguments.  They are:
+#   - The command being used for completion
+#   - The word being completed
+#   - The word preceding the completion word.
+#
+# Here's an example of how you might use this script:
+# $ complete -o bashdefault -o default -o nospace -C                         \
+#   '/usr/local/bin/gflags_completions.sh --tab_completion_columns $COLUMNS' \
+#   time  env  binary_name  another_binary  [...]
+
+# completion_word_index gets the index of the (N-1)th argument for
+# this command line.  completion_word gets the actual argument from
+# this command line at the (N-1)th position
+completion_word_index="$(($# - 1))"
+completion_word="${!completion_word_index}"
+
+# TODO(daven): Replace this once commandlineflags_completions.cc has
+# a bool parameter indicating unambiguously to hijack the process for
+# completion purposes.
+if [ -z "$completion_word" ]; then
+  # Until an empty value for the completion word stops being misunderstood
+  # by google3 binaries, don't actuall execute the binary or the process
+  # won't be hijacked!
+  exit 0
+fi
+
+# binary_index gets the index of the command being completed (which bash
+# places in the (N-2)nd position.  binary gets the actual command from
+# this command line at that (N-2)nd position
+binary_index="$(($# - 2))"
+binary="${!binary_index}"
+
+# For completions to be universal, we may have setup the compspec to
+# trigger on 'harmless pass-through' commands, like 'time' or 'env'.
+# If the command being completed is one of those two, we'll need to
+# identify the actual command being executed.  To do this, we need
+# the actual command line that the <TAB> was pressed on.  Bash helpfully
+# places this in the $COMP_LINE variable.
+if [ "$binary" == "time" ] || [ "$binary" == "env" ]; then
+  # we'll assume that the first 'argument' is actually the
+  # binary to be run, if we think it looks like a google3
+  # binary
+
+  # TODO(daven): Decide what 'looks' like a google3 binary.  =)
+
+  # TODO(daven): This is not perfect - the 'env' command, for instance,
+  #   is allowed to have options between the 'env' and 'the command to
+  #   be executed'.  For example, consider:
+  # $ env FOO="bar"  bin/do_something  --help<TAB>
+  # In this case, we'll mistake the FOO="bar" portion as the binary.
+  #   Perhaps we should continuing consuming leading words until we
+  #   either run out of words, or find a word that is a valid file
+  #   marked as executable.  I can't think of any reason this wouldn't
+  #   work.
+
+  # Break up the 'original command line' (not this script's command line,
+  # rather the one the <TAB> was pressed on) and find the second word.
+  parts=( ${COMP_LINE} )
+  binary=${parts[1]}
+fi
+
+# Build the command line to use for completion.  Basically it involves
+# passing through all the arguments given to this script (except the 3
+# that bash added), and appending a '--tab_completion_word "WORD"' to
+# the arguments.
+params=""
+for ((i=1; i<=$(($# - 3)); ++i)); do 
+  params="$params \"${!i}\"";
+done
+params="$params --tab_completion_word \"$completion_word\""
+
+# TODO(daven): Perhaps stash the output in a temporary file somewhere
+# in /tmp, and only cat it to stdout if the command returned a success
+# code, to prevent false positives
+
+# If we think we have a reasonable command to execute, then execute it
+# and hope for the best.
+if [ -f "$binary" ] && [ -x "$binary" ]; then
+  eval "$binary 2>/dev/null $params"
+fi
+