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# dialog.py --- A python interface to the Linux "dialog" utility
# Copyright (C) 2000 Robb Shecter, Sultanbek Tezadov
# Copyright (C) 2002, 2003, 2004 Florent Rougon
#
# This library is free software; you can redistribute it and/or
# modify it under the terms of the GNU Lesser General Public
# License as published by the Free Software Foundation; either
# version 2.1 of the License, or (at your option) any later version.
#
# This library is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
# Lesser General Public License for more details.
#
# You should have received a copy of the GNU Lesser General Public
# License along with this library; if not, write to the Free Software
# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
"""Python interface to dialog-like programs.
This module provides a Python interface to dialog-like programs such
as `dialog', `Xdialog' and `whiptail'.
It provides a Dialog class that retains some parameters such as the
program name and path as well as the values to pass as DIALOG*
environment variables to the chosen program.
For a quick start, you should look at the demo.py file that comes
with pythondialog. It demonstrates a simple use of each widget
offered by the Dialog class.
See the Dialog class documentation for general usage information,
list of available widgets and ways to pass options to dialog.
Notable exceptions
------------------
Here is the hierarchy of notable exceptions raised by this module:
error
ExecutableNotFound
BadPythonDialogUsage
PythonDialogSystemError
PythonDialogIOError
PythonDialogOSError
PythonDialogErrorBeforeExecInChildProcess
PythonDialogReModuleError
UnexpectedDialogOutput
DialogTerminatedBySignal
DialogError
UnableToCreateTemporaryDirectory
PythonDialogBug
ProbablyPythonBug
As you can see, every exception `exc' among them verifies:
issubclass(exc, error)
so if you don't need fine-grained error handling, simply catch
`error' (which will probably be accessible as dialog.error from your
program) and you should be safe.
"""
from __future__ import nested_scopes
import sys, os, tempfile, random, string, re, types
# Python < 2.3 compatibility
if sys.hexversion < 0x02030000:
# The assignments would work with Python >= 2.3 but then, pydoc
# shows them in the DATA section of the module...
True = 0 == 0
False = 0 == 1
# Exceptions raised by this module
#
# When adding, suppressing, renaming exceptions or changing their
# hierarchy, don't forget to update the module's docstring.
class error(Exception):
"""Base class for exceptions in pythondialog."""
def __init__(self, message=None):
self.message = message
def __str__(self):
return "<%s: %s>" % (self.__class__.__name__, self.message)
def complete_message(self):
if self.message:
return "%s: %s" % (self.ExceptionShortDescription, self.message)
else:
return "%s" % self.ExceptionShortDescription
ExceptionShortDescription = "pythondialog generic exception"
# For backward-compatibility
#
# Note: this exception was not documented (only the specific ones were), so
# the backward-compatibility binding could be removed relatively easily.
PythonDialogException = error
class ExecutableNotFound(error):
"""Exception raised when the dialog executable can't be found."""
ExceptionShortDescription = "Executable not found"
class PythonDialogBug(error):
"""Exception raised when pythondialog finds a bug in his own code."""
ExceptionShortDescription = "Bug in pythondialog"
# Yeah, the "Probably" makes it look a bit ugly, but:
# - this is more accurate
# - this avoids a potential clash with an eventual PythonBug built-in
# exception in the Python interpreter...
class ProbablyPythonBug(error):
"""Exception raised when pythondialog behaves in a way that seems to \
indicate a Python bug."""
ExceptionShortDescription = "Bug in python, probably"
class BadPythonDialogUsage(error):
"""Exception raised when pythondialog is used in an incorrect way."""
ExceptionShortDescription = "Invalid use of pythondialog"
class PythonDialogSystemError(error):
"""Exception raised when pythondialog cannot perform a "system \
operation" (e.g., a system call) that should work in "normal" situations.
This is a convenience exception: PythonDialogIOError, PythonDialogOSError
and PythonDialogErrorBeforeExecInChildProcess all derive from this
exception. As a consequence, watching for PythonDialogSystemError instead
of the aformentioned exceptions is enough if you don't need precise
details about these kinds of errors.
Don't confuse this exception with Python's builtin SystemError
exception.
"""
ExceptionShortDescription = "System error"
class PythonDialogIOError(PythonDialogSystemError):
"""Exception raised when pythondialog catches an IOError exception that \
should be passed to the calling program."""
ExceptionShortDescription = "IO error"
class PythonDialogOSError(PythonDialogSystemError):
"""Exception raised when pythondialog catches an OSError exception that \
should be passed to the calling program."""
ExceptionShortDescription = "OS error"
class PythonDialogErrorBeforeExecInChildProcess(PythonDialogSystemError):
"""Exception raised when an exception is caught in a child process \
before the exec sytem call (included).
This can happen in uncomfortable situations like when the system is out
of memory or when the maximum number of open file descriptors has been
reached. This can also happen if the dialog-like program was removed
(or if it is has been made non-executable) between the time we found it
with _find_in_path and the time the exec system call attempted to
execute it...
"""
ExceptionShortDescription = "Error in a child process before the exec " \
"system call"
class PythonDialogReModuleError(PythonDialogSystemError):
"""Exception raised when pythondialog catches a re.error exception."""
ExceptionShortDescription = "'re' module error"
class UnexpectedDialogOutput(error):
"""Exception raised when the dialog-like program returns something not \
expected by pythondialog."""
ExceptionShortDescription = "Unexpected dialog output"
class DialogTerminatedBySignal(error):
"""Exception raised when the dialog-like program is terminated by a \
signal."""
ExceptionShortDescription = "dialog-like terminated by a signal"
class DialogError(error):
"""Exception raised when the dialog-like program exits with the \
code indicating an error."""
ExceptionShortDescription = "dialog-like terminated due to an error"
class UnableToCreateTemporaryDirectory(error):
"""Exception raised when we cannot create a temporary directory."""
ExceptionShortDescription = "unable to create a temporary directory"
# Values accepted for checklists
try:
_on_rec = re.compile(r"on", re.IGNORECASE)
_off_rec = re.compile(r"off", re.IGNORECASE)
_calendar_date_rec = re.compile(
r"(?P<day>\d\d)/(?P<month>\d\d)/(?P<year>\d\d\d\d)$")
_timebox_time_rec = re.compile(
r"(?P<hour>\d\d):(?P<minute>\d\d):(?P<second>\d\d)$")
except re.error, v:
raise PythonDialogReModuleError(v)
# This dictionary allows us to write the dialog common options in a Pythonic
# way (e.g. dialog_instance.checklist(args, ..., title="Foo", no_shadow=1)).
#
# Options such as --separate-output should obviously not be set by the user
# since they affect the parsing of dialog's output:
_common_args_syntax = {
"aspect": lambda ratio: ("--aspect", str(ratio)),
"backtitle": lambda backtitle: ("--backtitle", backtitle),
"beep": lambda enable: _simple_option("--beep", enable),
"beep_after": lambda enable: _simple_option("--beep-after", enable),
# Warning: order = y, x!
"begin": lambda coords: ("--begin", str(coords[0]), str(coords[1])),
"cancel": lambda string: ("--cancel-label", string),
"cancel_label": lambda string: ("--cancel-label", string),
"clear": lambda enable: _simple_option("--clear", enable),
"colors": lambda enable: _simple_option("--colors", enable),
"cr_wrap": lambda enable: _simple_option("--cr-wrap", enable),
"create_rc": lambda file: ("--create-rc", file),
"defaultno": lambda enable: _simple_option("--defaultno", enable),
"default_item": lambda string: ("--default-item", string),
"help": lambda enable: _simple_option("--help", enable),
"help_button": lambda enable: _simple_option("--help-button", enable),
"help_label": lambda string: ("--help-label", string),
"insecure": lambda enable: _simple_option("--insecure", enable),
"ignore": lambda enable: _simple_option("--ignore", enable),
"item_help": lambda enable: _simple_option("--item-help", enable),
"max_input": lambda size: ("--max-input", str(size)),
"no_kill": lambda enable: _simple_option("--no-kill", enable),
"no_cancel": lambda enable: _simple_option("--no-cancel", enable),
"nocancel": lambda enable: _simple_option("--nocancel", enable),
"no_shadow": lambda enable: _simple_option("--no-shadow", enable),
"no_label": lambda string: ("--no-label", string),
"ok_label": lambda string: ("--ok-label", string),
"print_maxsize": lambda enable: _simple_option("--print-maxsize",
enable),
"print_size": lambda enable: _simple_option("--print-size", enable),
"print_version": lambda enable: _simple_option("--print-version",
enable),
"separate_output": lambda enable: _simple_option("--separate-output",
enable),
"separate_widget": lambda string: ("--separate-widget", string),
"shadow": lambda enable: _simple_option("--shadow", enable),
"size_err": lambda enable: _simple_option("--size-err", enable),
"sleep": lambda secs: ("--sleep", str(secs)),
"stderr": lambda enable: _simple_option("--stderr", enable),
"stdout": lambda enable: _simple_option("--stdout", enable),
"tab_correct": lambda enable: _simple_option("--tab-correct", enable),
"tab_len": lambda n: ("--tab-len", str(n)),
"timeout": lambda secs: ("--timeout", str(secs)),
"title": lambda title: ("--title", title),
"trim": lambda enable: _simple_option("--trim", enable),
"version": lambda enable: _simple_option("--version", enable),
"yes_label": lambda string: ("--yes-label", string)}
def _simple_option(option, enable):
"""Turn on or off the simplest dialog Common Options."""
if enable:
return (option,)
else:
# This will not add any argument to the command line
return ()
def _find_in_path(prog_name):
"""Search an executable in the PATH.
If PATH is not defined, the default path ":/bin:/usr/bin" is
used.
Return a path to the file or None if no readable and executable
file is found.
Notable exception: PythonDialogOSError
"""
try:
# Note that the leading empty component in the default value for PATH
# could lead to the returned path not being absolute.
PATH = os.getenv("PATH", ":/bin:/usr/bin") # see the execvp(3) man page
for dir in string.split(PATH, ":"):
file_path = os.path.join(dir, prog_name)
if os.path.isfile(file_path) \
and os.access(file_path, os.R_OK | os.X_OK):
return file_path
return None
except os.error, v:
raise PythonDialogOSError(v.strerror)
def _path_to_executable(f):
"""Find a path to an executable.
Find a path to an executable, using the same rules as the POSIX
exec*p functions (see execvp(3) for instance).
If `f' contains a '/', it is assumed to be a path and is simply
checked for read and write permissions; otherwise, it is looked
for according to the contents of the PATH environment variable,
which defaults to ":/bin:/usr/bin" if unset.
The returned path is not necessarily absolute.
Notable exceptions:
ExecutableNotFound
PythonDialogOSError
"""
try:
if '/' in f:
if os.path.isfile(f) and \
os.access(f, os.R_OK | os.X_OK):
res = f
else:
raise ExecutableNotFound("%s cannot be read and executed" % f)
else:
res = _find_in_path(f)
if res is None:
raise ExecutableNotFound(
"can't find the executable for the dialog-like "
"program")
except os.error, v:
raise PythonDialogOSError(v.strerror)
return res
def _to_onoff(val):
"""Convert boolean expressions to "on" or "off"
This function converts every non-zero integer as well as "on",
"ON", "On" and "oN" to "on" and converts 0, "off", "OFF", etc. to
"off".
Notable exceptions:
PythonDialogReModuleError
BadPythonDialogUsage
"""
if type(val) == types.IntType:
if val:
return "on"
else:
return "off"
elif type(val) == types.StringType:
try:
if _on_rec.match(val):
return "on"
elif _off_rec.match(val):
return "off"
except re.error, v:
raise PythonDialogReModuleError(v)
else:
raise BadPythonDialogUsage("invalid boolean value: %s" % val)
def _compute_common_args(dict):
"""Compute the list of arguments for dialog common options.
Compute a list of the command-line arguments to pass to dialog
from a keyword arguments dictionary for options listed as "common
options" in the manual page for dialog. These are the options
that are not tied to a particular widget.
This allows to specify these options in a pythonic way, such as:
d.checklist(<usual arguments for a checklist>,
title="...",
backtitle="...")
instead of having to pass them with strings like "--title foo" or
"--backtitle bar".
Notable exceptions: None
"""
args = []
for key in dict.keys():
args.extend(_common_args_syntax[key](dict[key]))
return args
def _create_temporary_directory():
"""Create a temporary directory (securely).
Return the directory path.
Notable exceptions:
- UnableToCreateTemporaryDirectory
- PythonDialogOSError
- exceptions raised by the tempfile module (which are
unfortunately not mentioned in its documentation, at
least in Python 2.3.3...)
"""
find_temporary_nb_attempts = 5
for i in range(find_temporary_nb_attempts):
try:
# Using something >= 2**31 causes an error in Python 2.2...
tmp_dir = os.path.join(tempfile.gettempdir(),
"%s-%u" \
% ("pythondialog",
random.randint(0, 2**30-1)))
except os.error, v:
raise PythonDialogOSError(v.strerror)
try:
os.mkdir(tmp_dir, 0700)
except os.error:
continue
else:
break
else:
raise UnableToCreateTemporaryDirectory(
"somebody may be trying to attack us")
return tmp_dir
# DIALOG_OK, DIALOG_CANCEL, etc. are environment variables controlling
# dialog's exit status in the corresponding situation.
#
# Note:
# - 127 must not be used for any of the DIALOG_* values. It is used
# when a failure occurs in the child process before it exec()s
# dialog (where "before" includes a potential exec() failure).
# - 126 is also used (although in presumably rare situations).
_dialog_exit_status_vars = { "OK": 0,
"CANCEL": 1,
"ESC": 2,
"ERROR": 3,
"EXTRA": 4,
"HELP": 5 }
# Main class of the module
class Dialog:
"""Class providing bindings for dialog-compatible programs.
This class allows you to invoke dialog or a compatible program in
a pythonic way to build quicky and easily simple but nice text
interfaces.
An application typically creates one instance of the Dialog class
and uses it for all its widgets, but it is possible to use
concurrently several instances of this class with different
parameters (such as the background title) if you have the need
for this.
The exit code (exit status) returned by dialog is to be
compared with the DIALOG_OK, DIALOG_CANCEL, DIALOG_ESC,
DIALOG_ERROR, DIALOG_EXTRA and DIALOG_HELP attributes of the
Dialog instance (they are integers).
Note: although this class does all it can to allow the caller to
differentiate between the various reasons that caused a
dialog box to be closed, its backend, dialog 0.9a-20020309a
for my tests, doesn't always return DIALOG_ESC when the
user presses the ESC key, but often returns DIALOG_ERROR
instead. The exit codes returned by the corresponding
Dialog methods are of course just as wrong in these cases.
You've been warned.
Public methods of the Dialog class (mainly widgets)
---------------------------------------------------
The Dialog class has the following methods:
add_persistent_args
calendar
checklist
form
fselect
gauge_start
gauge_update
gauge_stop
infobox
inputbox
menu
msgbox
passwordbox
passwordform
radiolist
scrollbox
tailbox
textbox
timebox
yesno
clear (obsolete)
setBackgroundTitle (obsolete)
Passing dialog "Common Options"
-------------------------------
Every widget method has a **kwargs argument allowing you to pass
dialog so-called Common Options (see the dialog(1) manual page)
to dialog for this widget call. For instance, if `d' is a Dialog
instance, you can write:
d.checklist(args, ..., title="A Great Title", no_shadow=1)
The no_shadow option is worth looking at:
1. It is an option that takes no argument as far as dialog is
concerned (unlike the "--title" option, for instance). When
you list it as a keyword argument, the option is really
passed to dialog only if the value you gave it evaluates to
true, e.g. "no_shadow=1" will cause "--no-shadow" to be
passed to dialog whereas "no_shadow=0" will cause this
option not to be passed to dialog at all.
2. It is an option that has a hyphen (-) in its name, which you
must change into an underscore (_) to pass it as a Python
keyword argument. Therefore, "--no-shadow" is passed by
giving a "no_shadow=1" keyword argument to a Dialog method
(the leading two dashes are also consistently removed).
Exceptions
----------
Please refer to the specific methods' docstrings or simply to the
module's docstring for a list of all exceptions that might be
raised by this class' methods.
"""
def __init__(self, dialog="dialog", DIALOGRC=None, compat="dialog",
use_stdout=None):
"""Constructor for Dialog instances.
dialog -- name of (or path to) the dialog-like program to
use; if it contains a '/', it is assumed to be a
path and is used as is; otherwise, it is looked
for according to the contents of the PATH
environment variable, which defaults to
":/bin:/usr/bin" if unset.
DIALOGRC -- string to pass to the dialog-like program as the
DIALOGRC environment variable, or None if no
modification to the environment regarding this
variable should be done in the call to the
dialog-like program
compat -- compatibility mode (see below)
The officially supported dialog-like program in pythondialog
is the well-known dialog program written in C, based on the
ncurses library. It is also known as cdialog and its home
page is currently (2004-03-15) located at:
http://dickey.his.com/dialog/dialog.html
If you want to use a different program such as Xdialog, you
should indicate the executable file name with the `dialog'
argument *and* the compatibility type that you think it
conforms to with the `compat' argument. Currently, `compat'
can be either "dialog" (for dialog; this is the default) or
"Xdialog" (for, well, Xdialog).
The `compat' argument allows me to cope with minor
differences in behaviour between the various programs
implementing the dialog interface (not the text or graphical
interface, I mean the "API"). However, having to support
various APIs simultaneously is a bit ugly and I would really
prefer you to report bugs to the relevant maintainers when
you find incompatibilities with dialog. This is for the
benefit of pretty much everyone that relies on the dialog
interface.
Notable exceptions:
ExecutableNotFound
PythonDialogOSError
"""
# DIALOGRC differs from the other DIALOG* variables in that:
# 1. It should be a string if not None
# 2. We may very well want it to be unset
if DIALOGRC is not None:
self.DIALOGRC = DIALOGRC
# After reflexion, I think DIALOG_OK, DIALOG_CANCEL, etc.
# should never have been instance attributes (I cannot see a
# reason why the user would want to change their values or
# even read them), but it is a bit late, now. So, we set them
# based on the (global) _dialog_exit_status_vars.keys.
for var in _dialog_exit_status_vars.keys():
varname = "DIALOG_" + var
setattr(self, varname, _dialog_exit_status_vars[var])
self._dialog_prg = _path_to_executable(dialog)
self.compat = compat
self.dialog_persistent_arglist = []
# Use stderr or stdout?
if self.compat == "Xdialog":
# Default to stdout if Xdialog
self.use_stdout = True
else:
self.use_stdout = False
if use_stdout != None:
# Allow explicit setting
self.use_stdout = use_stdout
if self.use_stdout:
self.add_persistent_args(["--stdout"])
def add_persistent_args(self, arglist):
self.dialog_persistent_arglist.extend(arglist)
# For compatibility with the old dialog...
def setBackgroundTitle(self, text):
"""Set the background title for dialog.
This method is obsolete. Please remove calls to it from your
programs.
"""
self.add_persistent_args(("--backtitle", text))
def _call_program(self, redirect_child_stdin, cmdargs, **kwargs):
"""Do the actual work of invoking the dialog-like program.
Communication with the dialog-like program is performed
through one or two pipes, depending on
`redirect_child_stdin'. There is always one pipe that is
created to allow the parent process to read what dialog
writes on its standard error stream.
If `redirect_child_stdin' is True, an additional pipe is
created whose reading end is connected to dialog's standard
input. This is used by the gauge widget to feed data to
dialog.
Beware when interpreting the return value: the length of the
returned tuple depends on `redirect_child_stdin'.
Notable exception: PythonDialogOSError (if pipe() or close()
system calls fail...)
"""
# We want to define DIALOG_OK, DIALOG_CANCEL, etc. in the
# environment of the child process so that we know (and
# even control) the possible dialog exit statuses.
new_environ = {}
new_environ.update(os.environ)
for var in _dialog_exit_status_vars:
varname = "DIALOG_" + var
new_environ[varname] = str(getattr(self, varname))
if hasattr(self, "DIALOGRC"):
new_environ["DIALOGRC"] = self.DIALOGRC
# Create:
# - a pipe so that the parent process can read dialog's output on
# stdout/stderr
# - a pipe so that the parent process can feed data to dialog's
# stdin (this is needed for the gauge widget) if
# redirect_child_stdin is True
try:
# rfd = File Descriptor for Reading
# wfd = File Descriptor for Writing
(child_rfd, child_wfd) = os.pipe()
if redirect_child_stdin:
(child_stdin_rfd, child_stdin_wfd) = os.pipe()
except os.error, v:
raise PythonDialogOSError(v.strerror)
child_pid = os.fork()
if child_pid == 0:
# We are in the child process. We MUST NOT raise any exception.
try:
# The child process doesn't need these file descriptors
os.close(child_rfd)
if redirect_child_stdin:
os.close(child_stdin_wfd)
# We want:
# - dialog's output on stderr/stdout to go to child_wfd
# - data written to child_stdin_wfd to go to dialog's stdin
# if redirect_child_stdin is True
if self.use_stdout:
os.dup2(child_wfd, 1)
else:
os.dup2(child_wfd, 2)
if redirect_child_stdin:
os.dup2(child_stdin_rfd, 0)
arglist = [self._dialog_prg] + \
self.dialog_persistent_arglist + \
_compute_common_args(kwargs) + \
cmdargs
# Insert here the contents of the DEBUGGING file if you want
# to obtain a handy string of the complete command line with
# arguments quoted for the shell and environment variables
# set.
os.execve(self._dialog_prg, arglist, new_environ)
except:
os._exit(127)
# Should not happen unless there is a bug in Python
os._exit(126)
# We are in the father process.
#
# It is essential to close child_wfd, otherwise we will never
# see EOF while reading on child_rfd and the parent process
# will block forever on the read() call.
# [ after the fork(), the "reference count" of child_wfd from
# the operating system's point of view is 2; after the child exits,
# it is 1 until the father closes it itself; then it is 0 and a read
# on child_rfd encounters EOF once all the remaining data in
# the pipe has been read. ]
try:
os.close(child_wfd)
if redirect_child_stdin:
os.close(child_stdin_rfd)
return (child_pid, child_rfd, child_stdin_wfd)
else:
return (child_pid, child_rfd)
except os.error, v:
raise PythonDialogOSError(v.strerror)
def _wait_for_program_termination(self, child_pid, child_rfd):
"""Wait for a dialog-like process to terminate.
This function waits for the specified process to terminate,
raises the appropriate exceptions in case of abnormal
termination and returns the exit status and standard error
output of the process as a tuple: (exit_code, stderr_string).
`child_rfd' must be the file descriptor for the
reading end of the pipe created by self._call_program()
whose writing end was connected by self._call_program() to
the child process's standard error.
This function reads the process's output on standard error
from `child_rfd' and closes this file descriptor once
this is done.
Notable exceptions:
DialogTerminatedBySignal
DialogError
PythonDialogErrorBeforeExecInChildProcess
PythonDialogIOError
PythonDialogBug
ProbablyPythonBug
"""
exit_info = os.waitpid(child_pid, 0)[1]
if os.WIFEXITED(exit_info):
exit_code = os.WEXITSTATUS(exit_info)
# As we wait()ed for the child process to terminate, there is no
# need to call os.WIFSTOPPED()
elif os.WIFSIGNALED(exit_info):
raise DialogTerminatedBySignal("the dialog-like program was "
"terminated by signal %u" %
os.WTERMSIG(exit_info))
else:
raise PythonDialogBug("please report this bug to the "
"pythondialog maintainers")
if exit_code == self.DIALOG_ERROR:
raise DialogError("the dialog-like program exited with "
"code %d (was passed to it as the DIALOG_ERROR "
"environment variable)" % exit_code)
elif exit_code == 127:
raise PythonDialogErrorBeforeExecInChildProcess(
"perhaps the dialog-like program could not be executed; "
"perhaps the system is out of memory; perhaps the maximum "
"number of open file descriptors has been reached")
elif exit_code == 126:
raise ProbablyPythonBug(
"a child process returned with exit status 126; this might "
"be the exit status of the dialog-like program, for some "
"unknown reason (-> probably a bug in the dialog-like "
"program); otherwise, we have probably found a python bug")
# We might want to check here whether exit_code is really one of
# DIALOG_OK, DIALOG_CANCEL, etc. However, I prefer not doing it
# because it would break pythondialog for no strong reason when new
# exit codes are added to the dialog-like program.
#
# As it is now, if such a thing happens, the program using
# pythondialog may receive an exit_code it doesn't know about. OK, the
# programmer just has to tell the pythondialog maintainer about it and
# can temporarily set the appropriate DIALOG_* environment variable if
# he wants and assign the corresponding value to the Dialog instance's
# DIALOG_FOO attribute from his program. He doesn't even need to use a
# patched pythondialog before he upgrades to a version that knows
# about the new exit codes.
#
# The bad thing that might happen is a new DIALOG_FOO exit code being
# the same by default as one of those we chose for the other exit
# codes already known by pythondialog. But in this situation, the
# check that is being discussed wouldn't help at all.
# Read dialog's output on its stderr
try:
child_output = os.fdopen(child_rfd, "rb").read()
# Now, since the file object has no reference anymore, the
# standard IO stream behind it will be closed, causing the
# end of the the pipe we used to read dialog's output on its
# stderr to be closed (this is important, otherwise invoking
# dialog enough times will eventually exhaust the maximum number
# of open file descriptors).
except IOError, v:
raise PythonDialogIOError(v)
return (exit_code, child_output)
def _perform(self, cmdargs, **kwargs):
"""Perform a complete dialog-like program invocation.
This function invokes the dialog-like program, waits for its
termination and returns its exit status and whatever it wrote
on its standard error stream.
Notable exceptions:
any exception raised by self._call_program() or
self._wait_for_program_termination()
"""
(child_pid, child_rfd) = \
self._call_program(False, *(cmdargs,), **kwargs)
(exit_code, output) = \
self._wait_for_program_termination(child_pid,
child_rfd)
return (exit_code, output)
def _strip_xdialog_newline(self, output):
"""Remove trailing newline (if any), if using Xdialog"""
if self.compat == "Xdialog" and output.endswith("\n"):
output = output[:-1]
return output
# This is for compatibility with the old dialog.py
def _perform_no_options(self, cmd):
"""Call dialog without passing any more options."""
return os.system(self._dialog_prg + ' ' + cmd)
# For compatibility with the old dialog.py
def clear(self):
"""Clear the screen. Equivalent to the dialog --clear option.
This method is obsolete. Please remove calls to it from your
programs.
"""
self._perform_no_options('--clear')
def form(self, text, height=20, width=50, form_height=20, fields=[], **kwargs):
"""Display a form dialog box.
text -- text to display in the box
height -- height of the box (minus the calendar height)
width -- width of the box
form_height -- height of the form
fields -- a list of tuples, each tuple has the form:
(label, item, len) or
(label, item, field_len, input_len)
it returns a tuple of the form (code, results), where results is a
list of the results.
Notable exceptions:
- any exception raised by self._perform()
- UnexpectedDialogOutput
- PythonDialogReModuleError
"""
cmd = ["--form", text, str(height), str(width), str(form_height)]
# find the longest label so we can put the input boxes at the
# correct offset
max_label_len = 0
for t in fields:
if len(t[0]) > max_label_len:
max_label_len = len(t[0]);
line = 1
for t in fields:
label = t[0]
item = t[1]
if item is None:
item = ""
field_len = str(t[2])
if len(t) < 4:
input_len = field_len
else:
input_len = str(t[3])
cmd.extend(((label, str(line), "1", item, str(line), str(max_label_len + 2), field_len, input_len)))
line += 1
(code, output) = self._perform(*(cmd,), **kwargs)
if output:
return (code, string.split(output, '\n')[:-1])
else: # empty selection
return (code, [])
def passwordform(self, text, height=20, width=50, form_height=20, fields=[], **kwargs):
"""Display a form dialog box.
text -- text to display in the box
height -- height of the box (minus the calendar height)
width -- width of the box
form_height -- height of the form
fields -- a list of tuples, each tuple has the form:
(label, item, len) or
(label, item, field_len, input_len)
it returns a tuple of the form (code, results), where results is a
list of the results.
Notable exceptions:
- any exception raised by self._perform()
- UnexpectedDialogOutput
- PythonDialogReModuleError
"""
cmd = ["--passwordform", text, str(height), str(width), str(form_height)]
# find the longest label so we can put the input boxes at the
# correct offset
max_label_len = 0
for t in fields:
if len(t[0]) > max_label_len:
max_label_len = len(t[0]);
line = 1
for t in fields:
label = t[0]
item = t[1]
field_len = str(t[2])
if len(t) < 4:
input_len = field_len
else:
input_len = str(t[3])
cmd.extend(((label, str(line), "1", item, str(line), str(max_label_len + 2), field_len, input_len)))
line += 1
# typing in password without stars is really awkward
kwargs["insecure"] = True
(code, output) = self._perform(*(cmd,), **kwargs)
if output:
return (code, string.split(output, '\n')[:-1])
else: # empty selection
return (code, [])
def calendar(self, text, height=6, width=0, day=0, month=0, year=0,
**kwargs):
"""Display a calendar dialog box.
text -- text to display in the box
height -- height of the box (minus the calendar height)
width -- width of the box
day -- inititial day highlighted
month -- inititial month displayed
year -- inititial year selected (0 causes the current date
to be used as the initial date)
A calendar box displays month, day and year in separately
adjustable windows. If the values for day, month or year are
missing or negative, the current date's corresponding values
are used. You can increment or decrement any of those using
the left, up, right and down arrows. Use tab or backtab to
move between windows. If the year is given as zero, the
current date is used as an initial value.
Return a tuple of the form (code, date) where `code' is the
exit status (an integer) of the dialog-like program and
`date' is a list of the form [day, month, year] (where `day',
`month' and `year' are integers corresponding to the date
chosen by the user) if the box was closed with OK, or None if
it was closed with the Cancel button.
Notable exceptions:
- any exception raised by self._perform()
- UnexpectedDialogOutput
- PythonDialogReModuleError
"""
(code, output) = self._perform(
*(["--calendar", text, str(height), str(width), str(day),
str(month), str(year)],),
**kwargs)
if code == self.DIALOG_OK:
try:
mo = _calendar_date_rec.match(output)
except re.error, v:
raise PythonDialogReModuleError(v)
if mo is None:
raise UnexpectedDialogOutput(
"the dialog-like program returned the following "
"unexpected date with the calendar box: %s" % output)
date = map(int, mo.group("day", "month", "year"))
else:
date = None
return (code, date)
def checklist(self, text, height=15, width=54, list_height=7,
choices=[], **kwargs):
"""Display a checklist box.
text -- text to display in the box
height -- height of the box
width -- width of the box
list_height -- number of entries displayed in the box (which
can be scrolled) at a given time
choices -- a list of tuples (tag, item, status) where
`status' specifies the initial on/off state of
each entry; can be 0 or 1 (integers, 1 meaning
checked, i.e. "on"), or "on", "off" or any
uppercase variant of these two strings.
Return a tuple of the form (code, [tag, ...]) with the tags
for the entries that were selected by the user. `code' is the
exit status of the dialog-like program.
If the user exits with ESC or CANCEL, the returned tag list
is empty.
Notable exceptions:
any exception raised by self._perform() or _to_onoff()
"""
cmd = ["--checklist", text, str(height), str(width), str(list_height)]
for t in choices:
cmd.extend(((t[0], t[1], _to_onoff(t[2]))))
# The dialog output cannot be parsed reliably (at least in dialog
# 0.9b-20040301) without --separate-output (because double quotes in
# tags are escaped with backslashes, but backslashes are not
# themselves escaped and you have a problem when a tag ends with a
# backslash--the output makes you think you've encountered an embedded
# double-quote).
kwargs["separate_output"] = True
(code, output) = self._perform(*(cmd,), **kwargs)
# Since we used --separate-output, the tags are separated by a newline
# in the output. There is also a final newline after the last tag.
if output:
return (code, string.split(output, '\n')[:-1])
else: # empty selection
return (code, [])
def fselect(self, filepath, height, width, **kwargs):
"""Display a file selection dialog box.
filepath -- initial file path
height -- height of the box
width -- width of the box
The file-selection dialog displays a text-entry window in
which you can type a filename (or directory), and above that
two windows with directory names and filenames.
Here, filepath can be a file path in which case the file and
directory windows will display the contents of the path and
the text-entry window will contain the preselected filename.
Use tab or arrow keys to move between the windows. Within the
directory or filename windows, use the up/down arrow keys to
scroll the current selection. Use the space-bar to copy the
current selection into the text-entry window.
Typing any printable character switches focus to the
text-entry window, entering that character as well as
scrolling the directory and filename windows to the closest
match.
Use a carriage return or the "OK" button to accept the
current value in the text-entry window, or the "Cancel"
button to cancel.
Return a tuple of the form (code, path) where `code' is the
exit status (an integer) of the dialog-like program and
`path' is the path chosen by the user (whose last element may
be a directory or a file).
Notable exceptions:
any exception raised by self._perform()
"""
(code, output) = self._perform(
*(["--fselect", filepath, str(height), str(width)],),
**kwargs)
output = self._strip_xdialog_newline(output)
return (code, output)
def gauge_start(self, text="", height=8, width=54, percent=0, **kwargs):
"""Display gauge box.
text -- text to display in the box
height -- height of the box
width -- width of the box
percent -- initial percentage shown in the meter
A gauge box displays a meter along the bottom of the box. The
meter indicates a percentage.
This function starts the dialog-like program telling it to
display a gauge box with a text in it and an initial
percentage in the meter.
Return value: undefined.
Gauge typical usage
-------------------
Gauge typical usage (assuming that `d' is an instance of the
Dialog class) looks like this:
d.gauge_start()
# do something
d.gauge_update(10) # 10% of the whole task is done
# ...
d.gauge_update(100, "any text here") # work is done
exit_code = d.gauge_stop() # cleanup actions
Notable exceptions:
- any exception raised by self._call_program()
- PythonDialogOSError
"""
(child_pid, child_rfd, child_stdin_wfd) = self._call_program(
True,
*(["--gauge", text, str(height), str(width), str(percent)],),
**kwargs)
try:
self._gauge_process = {
"pid": child_pid,
"stdin": os.fdopen(child_stdin_wfd, "wb"),
"child_rfd": child_rfd
}
except os.error, v:
raise PythonDialogOSError(v.strerror)
def gauge_update(self, percent, text="", update_text=0):
"""Update a running gauge box.
percent -- new percentage to show in the gauge meter
text -- new text to optionally display in the box
update-text -- boolean indicating whether to update the
text in the box
This function updates the percentage shown by the meter of a
running gauge box (meaning `gauge_start' must have been
called previously). If update_text is true (for instance, 1),
the text displayed in the box is also updated.
See the `gauge_start' function's documentation for
information about how to use a gauge.
Return value: undefined.
Notable exception: PythonDialogIOError can be raised if there
is an I/O error while writing to the pipe
used to talk to the dialog-like program.
"""
if update_text:
gauge_data = "%d\nXXX\n%s\nXXX\n" % (percent, text)
else:
gauge_data = "%d\n" % percent
try:
self._gauge_process["stdin"].write(gauge_data)
self._gauge_process["stdin"].flush()
except IOError, v:
raise PythonDialogIOError(v)
# For "compatibility" with the old dialog.py...
gauge_iterate = gauge_update
def gauge_stop(self):
"""Terminate a running gauge.
This function performs the appropriate cleanup actions to
terminate a running gauge (started with `gauge_start').
See the `gauge_start' function's documentation for
information about how to use a gauge.
Return value: undefined.
Notable exceptions:
- any exception raised by
self._wait_for_program_termination()
- PythonDialogIOError can be raised if closing the pipe
used to talk to the dialog-like program fails.
"""
p = self._gauge_process
# Close the pipe that we are using to feed dialog's stdin
try:
p["stdin"].close()
except IOError, v:
raise PythonDialogIOError(v)
exit_code = \
self._wait_for_program_termination(p["pid"],
p["child_rfd"])[0]
return exit_code
def infobox(self, text, height=10, width=30, **kwargs):
"""Display an information dialog box.
text -- text to display in the box
height -- height of the box
width -- width of the box
An info box is basically a message box. However, in this
case, dialog will exit immediately after displaying the
message to the user. The screen is not cleared when dialog
exits, so that the message will remain on the screen until
the calling shell script clears it later. This is useful
when you want to inform the user that some operations are
carrying on that may require some time to finish.
Return the exit status (an integer) of the dialog-like
program.
Notable exceptions:
any exception raised by self._perform()
"""
return self._perform(
*(["--infobox", text, str(height), str(width)],),
**kwargs)[0]
def inputbox(self, text, height=10, width=30, init='', **kwargs):
"""Display an input dialog box.
text -- text to display in the box
height -- height of the box
width -- width of the box
init -- default input string
An input box is useful when you want to ask questions that
require the user to input a string as the answer. If init is
supplied it is used to initialize the input string. When
entering the string, the BACKSPACE key can be used to
correct typing errors. If the input string is longer than
can fit in the dialog box, the input field will be scrolled.
Return a tuple of the form (code, string) where `code' is the
exit status of the dialog-like program and `string' is the
string entered by the user.
Notable exceptions:
any exception raised by self._perform()
"""
(code, tag) = self._perform(
*(["--inputbox", text, str(height), str(width), init],),
**kwargs)
tag = self._strip_xdialog_newline(tag)
return (code, tag)
def menu(self, text, height=15, width=54, menu_height=7, choices=[],
**kwargs):
"""Display a menu dialog box.
text -- text to display in the box
height -- height of the box
width -- width of the box
menu_height -- number of entries displayed in the box (which
can be scrolled) at a given time
choices -- a sequence of (tag, item) or (tag, item, help)
tuples (the meaning of each `tag', `item' and
`help' is explained below)
Overview
--------
As its name suggests, a menu box is a dialog box that can be
used to present a list of choices in the form of a menu for
the user to choose. Choices are displayed in the order given.
Each menu entry consists of a `tag' string and an `item'
string. The tag gives the entry a name to distinguish it from
the other entries in the menu. The item is a short
description of the option that the entry represents.
The user can move between the menu entries by pressing the
UP/DOWN keys, the first letter of the tag as a hot-key, or
the number keys 1-9. There are menu-height entries displayed
in the menu at one time, but the menu will be scrolled if
there are more entries than that.
Providing on-line help facilities
---------------------------------
If this function is called with item_help=1 (keyword
argument), the option --item-help is passed to dialog and the
tuples contained in `choices' must contain 3 elements each :
(tag, item, help). The help string for the highlighted item
is displayed in the bottom line of the screen and updated as
the user highlights other items.
If item_help=0 or if this keyword argument is not passed to
this function, the tuples contained in `choices' must contain
2 elements each : (tag, item).
If this function is called with help_button=1, it must also
be called with item_help=1 (this is a limitation of dialog),
therefore the tuples contained in `choices' must contain 3
elements each as explained in the previous paragraphs. This
will cause a Help button to be added to the right of the
Cancel button (by passing --help-button to dialog).
Return value
------------
Return a tuple of the form (exit_info, string).
`exit_info' is either:
- an integer, being the the exit status of the dialog-like
program
- or the string "help", meaning that help_button=1 was
passed and that the user chose the Help button instead of
OK or Cancel.
The meaning of `string' depends on the value of exit_info:
- if `exit_info' is 0, `string' is the tag chosen by the
user
- if `exit_info' is "help", `string' is the `help' string
from the `choices' argument corresponding to the item
that was highlighted when the user chose the Help button
- otherwise (the user chose Cancel or pressed Esc, or there
was a dialog error), the value of `string' is undefined.
Notable exceptions:
any exception raised by self._perform()
"""
cmd = ["--menu", text, str(height), str(width), str(menu_height)]
for t in choices:
cmd.extend(t)
(code, output) = self._perform(*(cmd,), **kwargs)
output = self._strip_xdialog_newline(output)
if "help_button" in kwargs.keys() and output.startswith("HELP "):
return ("help", output[5:])
else:
return (code, output)
def msgbox(self, text, height=10, width=30, **kwargs):
"""Display a message dialog box.
text -- text to display in the box
height -- height of the box
width -- width of the box
A message box is very similar to a yes/no box. The only
difference between a message box and a yes/no box is that a
message box has only a single OK button. You can use this
dialog box to display any message you like. After reading
the message, the user can press the ENTER key so that dialog
will exit and the calling program can continue its
operation.
Return the exit status (an integer) of the dialog-like
program.
Notable exceptions:
any exception raised by self._perform()
"""
return self._perform(
*(["--msgbox", text, str(height), str(width)],),
**kwargs)[0]
def passwordbox(self, text, height=10, width=60, init='', **kwargs):
"""Display an password input dialog box.
text -- text to display in the box
height -- height of the box
width -- width of the box
init -- default input password
A password box is similar to an input box, except that the
text the user enters is not displayed. This is useful when
prompting for passwords or other sensitive information. Be
aware that if anything is passed in "init", it will be
visible in the system's process table to casual snoopers.
Also, it is very confusing to the user to provide them with a
default password they cannot see. For these reasons, using
"init" is highly discouraged.
Return a tuple of the form (code, password) where `code' is
the exit status of the dialog-like program and `password' is
the password entered by the user.
Notable exceptions:
any exception raised by self._perform()
"""
# typing in password without stars is really awkward
kwargs["insecure"] = True
(code, password) = self._perform(
*(["--passwordbox", text, str(height), str(width), init],),
**kwargs)
password = self._strip_xdialog_newline(password)
return (code, password)
def radiolist(self, text, height=15, width=54, list_height=7,
choices=[], **kwargs):
"""Display a radiolist box.
text -- text to display in the box
height -- height of the box
width -- width of the box
list_height -- number of entries displayed in the box (which
can be scrolled) at a given time
choices -- a list of tuples (tag, item, status) where
`status' specifies the initial on/off state
each entry; can be 0 or 1 (integers, 1 meaning
checked, i.e. "on"), or "on", "off" or any
uppercase variant of these two strings.
No more than one entry should be set to on.
A radiolist box is similar to a menu box. The main difference
is that you can indicate which entry is initially selected,
by setting its status to on.
Return a tuple of the form (code, tag) with the tag for the
entry that was chosen by the user. `code' is the exit status
of the dialog-like program.
If the user exits with ESC or CANCEL, or if all entries were
initially set to off and not altered before the user chose
OK, the returned tag is the empty string.
Notable exceptions:
any exception raised by self._perform() or _to_onoff()
"""
cmd = ["--radiolist", text, str(height), str(width), str(list_height)]
for t in choices:
cmd.extend(((t[0], t[1], _to_onoff(t[2]))))
(code, tag) = self._perform(*(cmd,), **kwargs)
tag = self._strip_xdialog_newline(tag)
return (code, tag)
def scrollbox(self, text, height=20, width=78, **kwargs):
"""Display a string in a scrollable box.
text -- text to display in the box
height -- height of the box
width -- width of the box
This method is a layer on top of textbox. The textbox option
in dialog allows to display file contents only. This method
allows you to display any text in a scrollable box. This is
simply done by creating a temporary file, calling textbox and
deleting the temporary file afterwards.
Return the dialog-like program's exit status.
Notable exceptions:
- UnableToCreateTemporaryDirectory
- PythonDialogIOError
- PythonDialogOSError
- exceptions raised by the tempfile module (which are
unfortunately not mentioned in its documentation, at
least in Python 2.3.3...)
"""
# In Python < 2.3, the standard library does not have
# tempfile.mkstemp(), and unfortunately, tempfile.mktemp() is
# insecure. So, I create a non-world-writable temporary directory and
# store the temporary file in this directory.
try:
# We want to ensure that f is already bound in the local
# scope when the finally clause (see below) is executed
f = 0
tmp_dir = _create_temporary_directory()
# If we are here, tmp_dir *is* created (no exception was raised),
# so chances are great that os.rmdir(tmp_dir) will succeed (as
# long as tmp_dir is empty).
#
# Don't move the _create_temporary_directory() call inside the
# following try statement, otherwise the user will always see a
# PythonDialogOSError instead of an
# UnableToCreateTemporaryDirectory because whenever
# UnableToCreateTemporaryDirectory is raised, the subsequent
# os.rmdir(tmp_dir) is bound to fail.
try:
fName = os.path.join(tmp_dir, "text")
# No race condition as with the deprecated tempfile.mktemp()
# since tmp_dir is not world-writable.
f = open(fName, "wb")
f.write(text)
f.close()
# Ask for an empty title unless otherwise specified
if not "title" in kwargs.keys():
kwargs["title"] = ""
return self._perform(
*(["--textbox", fName, str(height), str(width)],),
**kwargs)[0]
finally:
if type(f) == types.FileType:
f.close() # Safe, even several times
os.unlink(fName)
os.rmdir(tmp_dir)
except os.error, v:
raise PythonDialogOSError(v.strerror)
except IOError, v:
raise PythonDialogIOError(v)
def tailbox(self, filename, height=20, width=60, **kwargs):
"""Display the contents of a file in a dialog box, as in "tail -f".
filename -- name of the file whose contents is to be
displayed in the box
height -- height of the box
width -- width of the box
Display the contents of the specified file, updating the
dialog box whenever the file grows, as with the "tail -f"
command.
Return the exit status (an integer) of the dialog-like
program.
Notable exceptions:
any exception raised by self._perform()
"""
return self._perform(
*(["--tailbox", filename, str(height), str(width)],),
**kwargs)[0]
# No tailboxbg widget, at least for now.
def textbox(self, filename, height=20, width=60, **kwargs):
"""Display the contents of a file in a dialog box.
filename -- name of the file whose contents is to be
displayed in the box
height -- height of the box
width -- width of the box
A text box lets you display the contents of a text file in a
dialog box. It is like a simple text file viewer. The user
can move through the file by using the UP/DOWN, PGUP/PGDN
and HOME/END keys available on most keyboards. If the lines
are too long to be displayed in the box, the LEFT/RIGHT keys
can be used to scroll the text region horizontally. For more
convenience, forward and backward searching functions are
also provided.
Return the exit status (an integer) of the dialog-like
program.
Notable exceptions:
any exception raised by self._perform()
"""
# This is for backward compatibility... not that it is
# stupid, but I prefer explicit programming.
if not "title" in kwargs.keys():
kwargs["title"] = filename
return self._perform(
*(["--textbox", filename, str(height), str(width)],),
**kwargs)[0]
def timebox(self, text, height=3, width=30, hour=-1, minute=-1,
second=-1, **kwargs):
"""Display a time dialog box.
text -- text to display in the box
height -- height of the box
width -- width of the box
hour -- inititial hour selected
minute -- inititial minute selected
second -- inititial second selected
A dialog is displayed which allows you to select hour, minute
and second. If the values for hour, minute or second are
negative (or not explicitely provided, as they default to
-1), the current time's corresponding values are used. You
can increment or decrement any of those using the left-, up-,
right- and down-arrows. Use tab or backtab to move between
windows.
Return a tuple of the form (code, time) where `code' is the
exit status (an integer) of the dialog-like program and
`time' is a list of the form [hour, minute, second] (where
`hour', `minute' and `second' are integers corresponding to
the time chosen by the user) if the box was closed with OK,
or None if it was closed with the Cancel button.
Notable exceptions:
- any exception raised by self._perform()
- PythonDialogReModuleError
- UnexpectedDialogOutput
"""
(code, output) = self._perform(
*(["--timebox", text, str(height), str(width),
str(hour), str(minute), str(second)],),
**kwargs)
if code == self.DIALOG_OK:
try:
mo = _timebox_time_rec.match(output)
if mo is None:
raise UnexpectedDialogOutput(
"the dialog-like program returned the following "
"unexpected time with the --timebox option: %s" % output)
time = map(int, mo.group("hour", "minute", "second"))
except re.error, v:
raise PythonDialogReModuleError(v)
else:
time = None
return (code, time)
def yesno(self, text, height=10, width=30, **kwargs):
"""Display a yes/no dialog box.
text -- text to display in the box
height -- height of the box
width -- width of the box
A yes/no dialog box of size `height' rows by `width' columns
will be displayed. The string specified by `text' is
displayed inside the dialog box. If this string is too long
to fit in one line, it will be automatically divided into
multiple lines at appropriate places. The text string can
also contain the sub-string "\\n" or newline characters to
control line breaking explicitly. This dialog box is useful
for asking questions that require the user to answer either
yes or no. The dialog box has a Yes button and a No button,
in which the user can switch between by pressing the TAB
key.
Return the exit status (an integer) of the dialog-like
program.
Notable exceptions:
any exception raised by self._perform()
"""
return self._perform(
*(["--yesno", text, str(height), str(width)],),
**kwargs)[0]
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