Add tempeditor.py.

tempeditor.py

@@ -0,0 +1,75 @@
+import argparse
+import os
+import shlex
+import subprocess
+import sys
+import tempfile
+
+from voussoirkit import pipeable
+from voussoirkit import subproctools
+from voussoirkit import winwhich
+
+class NoEditor(Exception):
+    pass
+
+class BadStatus(Exception):
+    pass
+
+def tempeditor(initial_text=None):
+    editor = os.environ.get('EDITOR')
+    if not editor:
+        raise NoEditor('You do not have an EDITOR variable.')
+
+    command = shlex.split(editor)
+    command[0] = winwhich.which(command[0])
+
+    file = tempfile.TemporaryFile('r+', encoding='utf-8', prefix='tempeditor-', delete=False)
+    command.append(file.name)
+
+    if initial_text:
+        file.write(initial_text)
+
+    # The text editor may not be allowed to write to the file while Python has
+    # the file handle, so let's close it and re-open after the user is finished.
+    file.close()
+
+    status = subprocess.check_call(command)
+    if status == 0:
+        handle = open(file.name, 'r', encoding='utf-8')
+        text = handle.read()
+        handle.close()
+
+    try:
+        os.remove(file.name)
+    except Exception:
+        pass
+
+    if status == 0:
+        return text
+    else:
+        raise BadStatus(subproctools.format_command(command), status)
+
+def tempeditor_argparse(args):
+    initial_text = '\n'.join(pipeable.input(args.initial_text)) if args.initial_text else None
+    try:
+        text = tempeditor(initial_text=initial_text)
+        pipeable.output(text)
+        return 0
+    except NoEditor as exc:
+        pipeable.stderr(exc)
+        return 1
+    except BadStatus as exc:
+        pipeable.stderr(f'Command {exc.args[0]} returned status {exc.args[1]}.')
+        return 1
+
+def main(argv):
+    parser = argparse.ArgumentParser(description=__doc__)
+
+    parser.add_argument('--text', dest='initial_text', default=None)
+    parser.set_defaults(func=tempeditor_argparse)
+
+    args = parser.parse_args(argv)
+    return args.func(args)
+
+if __name__ == '__main__':
+    raise SystemExit(main(sys.argv[1:]))