| 1 | #! @PYTHON@ |
| 2 | ### -*-python-*- |
| 3 | ### |
| 4 | ### Catch input and trap it in an X window |
| 5 | ### |
| 6 | ### (c) 2008 Straylight/Edgeware |
| 7 | ### |
| 8 | |
| 9 | ###----- Licensing notice --------------------------------------------------- |
| 10 | ### |
| 11 | ### This file is part of the Edgeware X tools collection. |
| 12 | ### |
| 13 | ### X tools is free software; you can redistribute it and/or modify |
| 14 | ### it under the terms of the GNU General Public License as published by |
| 15 | ### the Free Software Foundation; either version 2 of the License, or |
| 16 | ### (at your option) any later version. |
| 17 | ### |
| 18 | ### X tools is distributed in the hope that it will be useful, |
| 19 | ### but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 20 | ### MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 21 | ### GNU General Public License for more details. |
| 22 | ### |
| 23 | ### You should have received a copy of the GNU General Public License |
| 24 | ### along with X tools; if not, write to the Free Software Foundation, |
| 25 | ### Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. |
| 26 | |
| 27 | VERSION = '@VERSION@' |
| 28 | |
| 29 | ###-------------------------------------------------------------------------- |
| 30 | ### External dependencies. |
| 31 | |
| 32 | import optparse as O |
| 33 | from sys import stdin, stdout, stderr, exit |
| 34 | import sys as SYS |
| 35 | import os as OS |
| 36 | import fcntl as FC |
| 37 | import errno as E |
| 38 | import subprocess as S |
| 39 | import pango as P |
| 40 | import signal as SIG |
| 41 | import traceback as TB |
| 42 | |
| 43 | import xtoys as XT |
| 44 | GTK, GDK, GO = XT.GTK, XT.GDK, XT.GO |
| 45 | |
| 46 | ###-------------------------------------------------------------------------- |
| 47 | ### Utilities. |
| 48 | |
| 49 | def nonblocking(file): |
| 50 | """ |
| 51 | Make the FILE be nonblocking. |
| 52 | |
| 53 | FILE may be either an integer file descriptor, or something whose fileno |
| 54 | method yields up a file descriptor. |
| 55 | """ |
| 56 | if isinstance(file, int): |
| 57 | fd = file |
| 58 | else: |
| 59 | fd = file.fileno() |
| 60 | flags = FC.fcntl(fd, FC.F_GETFL) |
| 61 | FC.fcntl(fd, FC.F_SETFL, flags | OS.O_NONBLOCK) |
| 62 | |
| 63 | class complain (object): |
| 64 | """ |
| 65 | Function decorator: catch exceptions and report them in an error box. |
| 66 | |
| 67 | Example: |
| 68 | |
| 69 | @complain(DEFAULT) |
| 70 | def foo(...): |
| 71 | ... |
| 72 | |
| 73 | The decorated function is called normally. If no exception occurs (or at |
| 74 | least none propagates out of the function) then it returns normally too. |
| 75 | Otherwise, the exception is trapped and displayed in a Message window, and |
| 76 | the function returns DEFAULT, which defaults to None. |
| 77 | """ |
| 78 | |
| 79 | def __init__(me, default = None): |
| 80 | """Initializer: store the DEFAULT value for later.""" |
| 81 | me._default = default |
| 82 | |
| 83 | def __call__(me, func): |
| 84 | """Decorate the function.""" |
| 85 | def _(*args, **kw): |
| 86 | try: |
| 87 | return func(*args, **kw) |
| 88 | except: |
| 89 | type, info, _ = SYS.exc_info() |
| 90 | if isinstance(type, str): |
| 91 | head = 'Unexpected exception' |
| 92 | msg = type |
| 93 | else: |
| 94 | head = type.__name__ |
| 95 | msg = ', '.join(info.args) |
| 96 | XT.Message(title = 'Error!', type = 'error', headline = head, |
| 97 | buttons = ['gtk-ok'], message = msg).ask() |
| 98 | return me._default |
| 99 | return _ |
| 100 | |
| 101 | ###-------------------------------------------------------------------------- |
| 102 | ### Watching processes. |
| 103 | |
| 104 | class Reaper (object): |
| 105 | """ |
| 106 | The Reaper catches SIGCHLD and collects exit statuses. |
| 107 | |
| 108 | There should ideally be only one instance of the class; the reaper method |
| 109 | returns the instance, creating it if necessary. (The reaper uses up |
| 110 | resources which we can avoid wasting under some circumstances.) |
| 111 | |
| 112 | Call add(KID, FUNC) to watch process-id KID; when it exits, the reaper |
| 113 | calls FUNC(KID, STATUS), where STATUS is the exit status directly from |
| 114 | wait. |
| 115 | |
| 116 | Even though SIGCHLD occurs at unpredictable times, processes are not reaped |
| 117 | until we return to the GTK event loop. This means that you can safely |
| 118 | create processes and add them without needing to interlock with the reaper |
| 119 | in complicated ways, and it also means that handler functions are not |
| 120 | called at unpredictable times. |
| 121 | """ |
| 122 | |
| 123 | def __init__(me): |
| 124 | """ |
| 125 | Initialize the reaper. |
| 126 | |
| 127 | We create a pipe and register the read end of it with the GTK event |
| 128 | system. The SIGCHLD handler writes a byte to the pipe. |
| 129 | """ |
| 130 | me._kidmap = {} |
| 131 | me._prd, pwr = OS.pipe() |
| 132 | nonblocking(me._prd) |
| 133 | SIG.signal(SIG.SIGCHLD, lambda sig, tb: OS.write(pwr, '?')) |
| 134 | GO.io_add_watch(me._prd, GO.IO_IN | GO.IO_HUP, me._wake) |
| 135 | |
| 136 | _reaper = None |
| 137 | @classmethod |
| 138 | def reaper(cls): |
| 139 | """Return the instance of the Reaper, creating it if necessary.""" |
| 140 | if cls._reaper is None: |
| 141 | cls._reaper = cls() |
| 142 | return cls._reaper |
| 143 | |
| 144 | def add(me, kid, func): |
| 145 | """ |
| 146 | Register the process-id KID with the reaper, calling FUNC when it exits. |
| 147 | |
| 148 | As described, FUNC is called with two arguments, the KID and its exit |
| 149 | status. |
| 150 | """ |
| 151 | me._kidmap[kid] = func |
| 152 | |
| 153 | def _wake(me, file, reason): |
| 154 | """ |
| 155 | Called when the event loop notices something in the signal pipe. |
| 156 | |
| 157 | We empty the pipe and then reap any processes which need it. |
| 158 | """ |
| 159 | |
| 160 | ## Empty the pipe. It doesn't matter how many bytes are stored in the |
| 161 | ## pipe, or what their contents are. |
| 162 | try: |
| 163 | while True: |
| 164 | OS.read(me._prd, 16384) |
| 165 | except OSError, err: |
| 166 | if err.errno != E.EAGAIN: |
| 167 | raise |
| 168 | |
| 169 | ## Reap processes and pass their exit statuses on. |
| 170 | while True: |
| 171 | try: |
| 172 | kid, st = OS.waitpid(-1, OS.WNOHANG) |
| 173 | except OSError, err: |
| 174 | if err.errno == E.ECHILD: |
| 175 | break |
| 176 | else: |
| 177 | raise |
| 178 | if kid == 0: |
| 179 | break |
| 180 | try: |
| 181 | func = me._kidmap[kid] |
| 182 | del me._kidmap[kid] |
| 183 | except KeyError: |
| 184 | continue |
| 185 | func(kid, st) |
| 186 | |
| 187 | ## Done: call me again. |
| 188 | return True |
| 189 | |
| 190 | ###-------------------------------------------------------------------------- |
| 191 | ### Catching and displaying output. |
| 192 | |
| 193 | class Catcher (object): |
| 194 | """ |
| 195 | Catcher objects watch an input file and display the results in a window. |
| 196 | |
| 197 | Initialization is a little cumbersome. You make an object, and then add a |
| 198 | file and maybe a process-id to watch. The catcher will not create a window |
| 199 | until it actually needs to display something. |
| 200 | |
| 201 | The object can be configured by setting attributes before it first opens |
| 202 | its window. |
| 203 | |
| 204 | * title: is the title for the window |
| 205 | * font: is the font to display text in, as a string |
| 206 | |
| 207 | The rc attribute is set to a suitable exit status. |
| 208 | """ |
| 209 | |
| 210 | def __init__(me): |
| 211 | """Initialize the catcher.""" |
| 212 | me.title = 'xcatch' |
| 213 | me._file = None |
| 214 | me._window = None |
| 215 | me._buf = None |
| 216 | me.font = None |
| 217 | me._openp = False |
| 218 | me.rc = 0 |
| 219 | |
| 220 | def watch_file(me, file): |
| 221 | """ |
| 222 | Watch the FILE for input. |
| 223 | |
| 224 | Any data arriving for the FILE is recoded into UTF-8 and displayed in the |
| 225 | window. The file not reaching EOF is considered a reason not to end the |
| 226 | program. |
| 227 | """ |
| 228 | XT.addreason() |
| 229 | nonblocking(file) |
| 230 | me._src = GO.io_add_watch(file, GO.IO_IN | GO.IO_HUP, me._ready) |
| 231 | me._file = file |
| 232 | |
| 233 | def watch_kid(me, kid): |
| 234 | """ |
| 235 | Watch the process-id KID for exit. |
| 236 | |
| 237 | If the child dies abnormally then a message is written to the window. |
| 238 | """ |
| 239 | XT.addreason() |
| 240 | Reaper.reaper().add(kid, me._exit) |
| 241 | |
| 242 | def make_window(me): |
| 243 | """ |
| 244 | Construct the output window if necessary. |
| 245 | |
| 246 | Having the window open is a reason to continue. |
| 247 | """ |
| 248 | |
| 249 | ## If the window exists, just make sure it's visible. |
| 250 | if me._window is not None: |
| 251 | if me._openp == False: |
| 252 | me._window.present() |
| 253 | XT.addreason() |
| 254 | me._openp = True |
| 255 | return |
| 256 | |
| 257 | ## Make the buffer. |
| 258 | buf = GTK.TextBuffer() |
| 259 | me._deftag = buf.create_tag('default') |
| 260 | if me.font is not None: |
| 261 | me._deftag.set_properties(font = me.font) |
| 262 | me._exittag = \ |
| 263 | buf.create_tag('exit', style_set = True, style = P.STYLE_ITALIC) |
| 264 | me._buf = buf |
| 265 | |
| 266 | ## Make the window. |
| 267 | win = GTK.Window(GTK.WINDOW_TOPLEVEL) |
| 268 | win.set_title(me.title) |
| 269 | win.connect('delete-event', me._delete) |
| 270 | win.connect('key-press-event', me._keypress) |
| 271 | view = GTK.TextView(buf) |
| 272 | view.set_editable(False) |
| 273 | scr = GTK.ScrolledWindow() |
| 274 | scr.set_policy(GTK.POLICY_AUTOMATIC, GTK.POLICY_AUTOMATIC) |
| 275 | scr.set_shadow_type(GTK.SHADOW_IN) |
| 276 | scr.add(view) |
| 277 | win.set_default_size(480, 200) |
| 278 | win.add(scr) |
| 279 | |
| 280 | ## All done. |
| 281 | win.show_all() |
| 282 | XT.addreason() |
| 283 | me._openp = True |
| 284 | me._window = win |
| 285 | |
| 286 | def _keypress(me, win, event): |
| 287 | """ |
| 288 | Handle a keypress on the window. |
| 289 | |
| 290 | Escape or Q will close the window. |
| 291 | """ |
| 292 | key = GDK.keyval_name(event.keyval) |
| 293 | if key in ['Escape', 'q', 'Q']: |
| 294 | me._delete() |
| 295 | return True |
| 296 | return False |
| 297 | |
| 298 | def _delete(me, *_): |
| 299 | """ |
| 300 | Handle a close request on the window. |
| 301 | |
| 302 | Closing the window removes a reason to continue. |
| 303 | """ |
| 304 | me._window.hide() |
| 305 | XT.delreason() |
| 306 | me._openp = False |
| 307 | return True |
| 308 | |
| 309 | @complain(True) |
| 310 | def _ready(me, file, *_): |
| 311 | """ |
| 312 | Process input arriving on the FILE. |
| 313 | """ |
| 314 | try: |
| 315 | buf = file.read(16384) |
| 316 | except IOError, err: |
| 317 | if err.errno == E.EAGAIN: |
| 318 | return True |
| 319 | me._close() |
| 320 | me.rc = 127 |
| 321 | raise |
| 322 | if buf == '': |
| 323 | me._close() |
| 324 | return True |
| 325 | me.make_window() |
| 326 | uni = buf.decode(SYS.getdefaultencoding(), 'replace') |
| 327 | utf8 = uni.encode('utf-8') |
| 328 | end = me._buf.get_end_iter() |
| 329 | me._buf.insert_with_tags(end, utf8, me._deftag) |
| 330 | return True |
| 331 | |
| 332 | def _close(me): |
| 333 | """ |
| 334 | Close the input file. |
| 335 | """ |
| 336 | XT.delreason() |
| 337 | GO.source_remove(me._src) |
| 338 | me._file = None |
| 339 | |
| 340 | def _exit(me, kid, st): |
| 341 | """ |
| 342 | Handle the child process exiting. |
| 343 | """ |
| 344 | if st == 0: |
| 345 | XT.delreason() |
| 346 | return |
| 347 | me.make_window() |
| 348 | XT.delreason() |
| 349 | end = me._buf.get_end_iter() |
| 350 | if not end.starts_line(): |
| 351 | me._buf.insert(end, '\n') |
| 352 | if OS.WIFEXITED(st): |
| 353 | msg = 'exited with status %d' % OS.WEXITSTATUS(st) |
| 354 | me.rc = OS.WEXITSTATUS(st) |
| 355 | elif OS.WIFSIGNALED(st): |
| 356 | msg = 'killed by signal %d' % OS.WTERMSIG(st) |
| 357 | me.rc = OS.WTERMSIG(st) | 128 |
| 358 | if OS.WCOREDUMP(st): |
| 359 | msg += ' (core dumped)' |
| 360 | else: |
| 361 | msg = 'exited with unknown code 0x%x' % st |
| 362 | me.rc = 255 |
| 363 | me._buf.insert_with_tags(end, '\n[%s]\n' % msg, |
| 364 | me._deftag, me._exittag) |
| 365 | |
| 366 | ###-------------------------------------------------------------------------- |
| 367 | ### Option parsing. |
| 368 | |
| 369 | def parse_args(): |
| 370 | """ |
| 371 | Parse the command line, returning a triple (PARSER, OPTS, ARGS). |
| 372 | """ |
| 373 | |
| 374 | op = XT.make_optparse \ |
| 375 | ([('f', 'file', |
| 376 | {'dest': 'file', |
| 377 | 'help': "Read input from FILE."}), |
| 378 | ('F', 'font', |
| 379 | {'dest': 'font', |
| 380 | 'help': "Display output using FONT."})], |
| 381 | version = VERSION, |
| 382 | usage = '%prog [-f FILE] [-F FONT] [COMMAND [ARGS...]]') |
| 383 | |
| 384 | op.set_defaults(file = None, |
| 385 | font = 'monospace') |
| 386 | |
| 387 | opts, args = op.parse_args() |
| 388 | if len(args) > 0 and opts.file is not None: |
| 389 | op.error("Can't read from a file and a command simultaneously.") |
| 390 | return op, opts, args |
| 391 | |
| 392 | ###-------------------------------------------------------------------------- |
| 393 | ### Main program. |
| 394 | |
| 395 | def main(): |
| 396 | |
| 397 | ## Check options. |
| 398 | op, opts, args = parse_args() |
| 399 | |
| 400 | ## Set up the file to read from. |
| 401 | catcher = Catcher() |
| 402 | if opts.file is not None: |
| 403 | if opts.file == '-': |
| 404 | name = '<stdin>' |
| 405 | catcher.watch_file(stdin) |
| 406 | else: |
| 407 | name = opts.file |
| 408 | catcher.watch_file(open(opts.file, 'r')) |
| 409 | elif len(args) == 0: |
| 410 | name = '<stdin>' |
| 411 | catcher.watch_file(stdin) |
| 412 | else: |
| 413 | name = ' '.join(args) |
| 414 | Reaper.reaper() |
| 415 | proc = S.Popen(args, stdout = S.PIPE, stderr = S.STDOUT) |
| 416 | catcher.watch_file(proc.stdout) |
| 417 | catcher.watch_kid(proc.pid) |
| 418 | |
| 419 | catcher.title = 'xcatch: ' + name |
| 420 | catcher.font = opts.font |
| 421 | |
| 422 | ## Let things run their course. |
| 423 | GTK.main() |
| 424 | exit(catcher.rc) |
| 425 | |
| 426 | if __name__ == '__main__': |
| 427 | main() |
| 428 | |
| 429 | ###----- That's all, folks -------------------------------------------------- |