editor.py

# Copyright (C) 2008 The Android Open Source Project
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#      http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

import os
import re
import sys
import subprocess
import tempfile

from error import EditorError
import platform_utils


class Editor(object):
    """Manages the user's preferred text editor."""

    _editor = None
    globalConfig = None

    @classmethod
    def _GetEditor(cls):
        if cls._editor is None:
            cls._editor = cls._SelectEditor()
        return cls._editor

    @classmethod
    def _SelectEditor(cls):
        e = os.getenv("GIT_EDITOR")
        if e:
            return e

        if cls.globalConfig:
            e = cls.globalConfig.GetString("core.editor")
            if e:
                return e

        e = os.getenv("VISUAL")
        if e:
            return e

        e = os.getenv("EDITOR")
        if e:
            return e

        if os.getenv("TERM") == "dumb":
            print(
                """No editor specified in GIT_EDITOR, core.editor, VISUAL or EDITOR.
Tried to fall back to vi but terminal is dumb.  Please configure at
least one of these before using this command.""",  # noqa: E501
                file=sys.stderr,
            )
            sys.exit(1)

        return "vi"

    @classmethod
    def EditString(cls, data):
        """Opens an editor to edit the given content.

        Args:
            data: The text to edit.

        Returns:
            New value of edited text.

        Raises:
            EditorError: The editor failed to run.
        """
        editor = cls._GetEditor()
        if editor == ":":
            return data

        fd, path = tempfile.mkstemp()
        try:
            os.write(fd, data.encode("utf-8"))
            os.close(fd)
            fd = None

            if platform_utils.isWindows():
                # Split on spaces, respecting quoted strings
                import shlex

                args = shlex.split(editor)
                shell = False
            elif re.compile("^.*[$ \t'].*$").match(editor):
                args = [editor + ' "$@"', "sh"]
                shell = True
            else:
                args = [editor]
                shell = False
            args.append(path)

            try:
                rc = subprocess.Popen(args, shell=shell).wait()
            except OSError as e:
                raise EditorError(
                    "editor failed, %s: %s %s" % (str(e), editor, path)
                )
            if rc != 0:
                raise EditorError(
                    "editor failed with exit status %d: %s %s"
                    % (rc, editor, path)
                )

            with open(path, mode="rb") as fd2:
                return fd2.read().decode("utf-8")
        finally:
            if fd:
                os.close(fd)
            platform_utils.remove(path)