OILS / builtin / read_osh.py View on Github | oils.pub

536 lines, 311 significant
1from __future__ import print_function
2
3from errno import EINTR
4
5from _devbuild.gen import arg_types
6from _devbuild.gen.runtime_asdl import (span_e, cmd_value)
7from _devbuild.gen.syntax_asdl import source, loc_t
8from _devbuild.gen.value_asdl import value, LeftName
9from core import alloc
10from core import error
11from core.error import e_die
12from core import pyos
13from core import pyutil
14from core import state
15from display import ui
16from core import vm
17from frontend import flag_util
18from frontend import reader
19from frontend import typed_args
20from mycpp import mops
21from mycpp import mylib
22from mycpp.mylib import log, STDIN_FILENO
23
24import posix_ as posix
25
26from typing import Tuple, List, Any, TYPE_CHECKING
27if TYPE_CHECKING:
28 from _devbuild.gen.runtime_asdl import span_t
29 from frontend.parse_lib import ParseContext
30 from frontend import args
31 from osh.cmd_eval import CommandEvaluator
32 from osh.split import SplitContext
33
34_ = log
35
36# The read builtin splits using IFS.
37#
38# Summary:
39# - Split with IFS, except \ can escape them! This is different than the
40# algorithm for splitting words (at least the way I've represented it.)
41
42# Bash manual:
43# - If there are more words than names, the remaining words and their
44# intervening delimiters are assigned to the last name.
45# - If there are fewer words read from the input stream than names, the
46# remaining names are assigned empty values.
47# - The characters in the value of the IFS variable are used to split the line
48# into words using the same rules the shell uses for expansion (described
49# above in Word Splitting).
50# - The backslash character '\' may be used to remove any special meaning for
51# the next character read and for line continuation.
52
53
54def _AppendParts(
55 s, # type: str
56 spans, # type: List[Tuple[span_t, int]]
57 max_results, # type: int
58 join_next, # type: bool
59 parts, # type: List[mylib.BufWriter]
60):
61 # type: (...) -> Tuple[bool, bool]
62 """Append to 'parts', for the 'read' builtin.
63
64 Similar to _SpansToParts in osh/split.py
65
66 Args:
67 s: The original string
68 spans: List of (span, end_index)
69 max_results: the maximum number of parts we want
70 join_next: Whether to join the next span to the previous part. This
71 happens in two cases:
72 - when we have '\ '
73 - and when we have more spans # than max_results.
74 """
75 start_index = 0
76 # If the last span was black, and we get a backslash, set join_next to merge
77 # two black spans.
78 last_span_was_black = False
79
80 for span_type, end_index in spans:
81 if span_type == span_e.Black:
82 if join_next and len(parts):
83 parts[-1].write(s[start_index:end_index])
84 join_next = False
85 else:
86 buf = mylib.BufWriter()
87 buf.write(s[start_index:end_index])
88 parts.append(buf)
89 last_span_was_black = True
90
91 elif span_type == span_e.Delim:
92 if join_next:
93 parts[-1].write(s[start_index:end_index])
94 join_next = False
95 last_span_was_black = False
96
97 elif span_type == span_e.Backslash:
98 if last_span_was_black:
99 join_next = True
100 last_span_was_black = False
101
102 if max_results and len(parts) >= max_results:
103 join_next = True
104
105 start_index = end_index
106
107 done = True
108 if len(spans):
109 #log('%s %s', s, spans)
110 #log('%s', spans[-1])
111 last_span_type, _ = spans[-1]
112 if last_span_type == span_e.Backslash:
113 done = False
114
115 #log('PARTS %s', parts)
116 return done, join_next
117
118
119#
120# Three read() wrappers for 'read' builtin that RunPendingTraps: _ReadN,
121# _ReadPortion, and ReadLineSlowly
122#
123
124
125def _ReadN(num_bytes, cmd_ev):
126 # type: (int, CommandEvaluator) -> str
127 chunks = [] # type: List[str]
128 bytes_left = num_bytes
129 while bytes_left > 0:
130 n, err_num = pyos.Read(STDIN_FILENO, bytes_left, chunks)
131
132 if n < 0:
133 if err_num == EINTR:
134 cmd_ev.RunPendingTraps()
135 # retry after running traps
136 else:
137 raise pyos.ReadError(err_num)
138
139 elif n == 0: # EOF
140 break
141
142 else:
143 bytes_left -= n
144
145 return ''.join(chunks)
146
147
148def _ReadPortion(delim_byte, max_chars, cmd_ev):
149 # type: (int, int, CommandEvaluator) -> Tuple[str, bool]
150 """Read a portion of stdin.
151
152 Reads until delimiter or max_chars, which ever comes first. Will ignore
153 max_chars if it's set to -1.
154
155 The delimiter is not included in the result.
156 """
157 ch_array = [] # type: List[int]
158 eof = False
159
160 bytes_read = 0
161 while True:
162 if max_chars >= 0 and bytes_read >= max_chars:
163 break
164
165 ch, err_num = pyos.ReadByte(0)
166 if ch < 0:
167 if err_num == EINTR:
168 cmd_ev.RunPendingTraps()
169 # retry after running traps
170 else:
171 raise pyos.ReadError(err_num)
172
173 elif ch == pyos.EOF_SENTINEL:
174 eof = True
175 break
176
177 elif ch == delim_byte:
178 break
179
180 elif ch == 0:
181 # Quirk of most shells except zsh: they ignore NUL bytes!
182 pass
183
184 else:
185 ch_array.append(ch)
186
187 bytes_read += 1
188
189 return pyutil.ChArrayToString(ch_array), eof
190
191
192def ReadLineSlowly(cmd_ev, with_eol=True):
193 # type: (CommandEvaluator, bool) -> Tuple[str, bool]
194 """Read a line from stdin, unbuffered
195
196 Used by mapfile and read --raw-line.
197
198 sys.stdin.readline() in Python has its own buffering which is incompatible
199 with shell semantics. dash, mksh, and zsh all read a single byte at a time
200 with read(0, 1).
201 """
202 ch_array = [] # type: List[int]
203 eof = False
204 is_first_byte = True
205 while True:
206 ch, err_num = pyos.ReadByte(0)
207 #log(' ch %d', ch)
208
209 if ch < 0:
210 if err_num == EINTR:
211 cmd_ev.RunPendingTraps()
212 # retry after running traps
213 else:
214 raise pyos.ReadError(err_num)
215
216 elif ch == pyos.EOF_SENTINEL:
217 if is_first_byte:
218 eof = True
219 break
220
221 elif ch == pyos.NEWLINE_CH:
222 if with_eol:
223 ch_array.append(ch)
224 break
225
226 else:
227 ch_array.append(ch)
228
229 is_first_byte = False
230
231 return pyutil.ChArrayToString(ch_array), eof
232
233
234def ReadAll():
235 # type: () -> str
236 """Read all of stdin.
237
238 Similar to command sub in core/executor.py.
239 """
240 chunks = [] # type: List[str]
241 while True:
242 n, err_num = pyos.Read(0, 4096, chunks)
243
244 if n < 0:
245 if err_num == EINTR:
246 # Retry only. Like read --line (and command sub), read --all
247 # doesn't run traps. It would be a bit weird to run every 4096
248 # bytes.
249 pass
250 else:
251 raise pyos.ReadError(err_num)
252
253 elif n == 0: # EOF
254 break
255
256 return ''.join(chunks)
257
258
259class ctx_TermAttrs(object):
260
261 def __init__(self, fd, local_modes):
262 # type: (int, int) -> None
263 self.fd = fd
264
265 # We change term_attrs[3] in Python, which is lflag "local modes"
266 self.orig_local_modes, self.term_attrs = pyos.PushTermAttrs(
267 fd, local_modes)
268
269 def __enter__(self):
270 # type: () -> None
271 pass
272
273 def __exit__(self, type, value, traceback):
274 # type: (Any, Any, Any) -> None
275 pyos.PopTermAttrs(self.fd, self.orig_local_modes, self.term_attrs)
276
277
278class Read(vm._Builtin):
279
280 def __init__(
281 self,
282 splitter, # type: SplitContext
283 mem, # type: state.Mem
284 parse_ctx, # type: ParseContext
285 cmd_ev, # type: CommandEvaluator
286 errfmt, # type: ui.ErrorFormatter
287 ):
288 # type: (...) -> None
289 self.splitter = splitter
290 self.mem = mem
291 self.parse_ctx = parse_ctx
292 self.cmd_ev = cmd_ev
293 self.errfmt = errfmt
294 self.stdin_ = mylib.Stdin()
295
296 # Was --qsn, might be restored as --j8-word or --j8-line
297 if 0:
298 #from data_lang import qsn_native
299 def _MaybeDecodeLine(self, line):
300 # type: (str) -> str
301 """Raises error.Parse if line isn't valid."""
302
303 # Lines that don't start with a single quote aren't QSN. They may
304 # contain a single quote internally, like:
305 #
306 # Fool's Gold
307 if not line.startswith("'"):
308 return line
309
310 arena = self.parse_ctx.arena
311 line_reader = reader.StringLineReader(line, arena)
312 lexer = self.parse_ctx.MakeLexer(line_reader)
313
314 # The parser only yields valid tokens:
315 # Char_OneChar, Char_Hex, Char_UBraced
316 # So we can use word_compile.EvalCStringToken, which is also used for
317 # $''.
318 # Important: we don't generate Id.Unknown_Backslash because that is valid
319 # in echo -e. We just make it Id.Unknown_Tok?
320
321 # TODO: read location info should know about stdin, and redirects, and
322 # pipelines?
323 with alloc.ctx_SourceCode(arena, source.Stdin('')):
324 #tokens = qsn_native.Parse(lexer)
325 pass
326 #tmp = [word_compile.EvalCStringToken(t) for t in tokens]
327 #return ''.join(tmp)
328 return ''
329
330 def Run(self, cmd_val):
331 # type: (cmd_value.Argv) -> int
332 try:
333 status = self._Run(cmd_val)
334 except pyos.ReadError as e: # different paths for read -d, etc.
335 # don't quote code since YSH errexit will likely quote
336 self.errfmt.PrintMessage("Oils read error: %s" %
337 posix.strerror(e.err_num))
338 status = 1
339 except (IOError, OSError) as e: # different paths for read -d, etc.
340 self.errfmt.PrintMessage("Oils read I/O error: %s" %
341 pyutil.strerror(e))
342 status = 1
343 return status
344
345 def _ReadYsh(self, arg, arg_r, cmd_val):
346 # type: (arg_types.read, args.Reader, cmd_value.Argv) -> int
347 """
348 Usage:
349
350 read --all # sets _reply
351 read --all (&x) # sets x
352
353 Invalid for now:
354
355 read (&x) # YSH doesn't have token splitting
356 # we probably want read --row too
357 """
358 place = None # type: value.Place
359
360 if cmd_val.proc_args: # read --flag (&x)
361 rd = typed_args.ReaderForProc(cmd_val)
362 place = rd.PosPlace()
363 rd.Done()
364
365 blame_loc = cmd_val.proc_args.typed_args.left # type: loc_t
366
367 else: # read --flag
368 var_name = '_reply'
369
370 #log('VAR %s', var_name)
371 blame_loc = cmd_val.arg_locs[0]
372 place = value.Place(LeftName(var_name, blame_loc),
373 self.mem.CurrentFrame())
374
375 next_arg, next_loc = arg_r.Peek2()
376 if next_arg is not None:
377 raise error.Usage('got extra argument', next_loc)
378
379 num_bytes = mops.BigTruncate(arg.num_bytes)
380 if num_bytes != -1: # read --num-bytes
381 contents = _ReadN(num_bytes, self.cmd_ev)
382 status = 0
383
384 elif arg.raw_line: # read --raw-line is unbuffered
385 contents, eof = ReadLineSlowly(self.cmd_ev, with_eol=arg.with_eol)
386 #log('EOF %s', eof)
387 #status = 1 if eof else 0
388 status = 1 if eof else 0
389
390 elif arg.all: # read --all
391 contents = ReadAll()
392 status = 0
393
394 else:
395 raise AssertionError()
396
397 self.mem.SetPlace(place, value.Str(contents), blame_loc)
398 return status
399
400 def _Run(self, cmd_val):
401 # type: (cmd_value.Argv) -> int
402 attrs, arg_r = flag_util.ParseCmdVal('read',
403 cmd_val,
404 accept_typed_args=True)
405 arg = arg_types.read(attrs.attrs)
406 names = arg_r.Rest()
407
408 if arg.u != mops.MINUS_ONE:
409 # TODO: could implement this
410 raise error.Usage('-u flag not implemented', cmd_val.arg_locs[0])
411
412 if arg.raw_line or arg.all or mops.BigTruncate(arg.num_bytes) != -1:
413 return self._ReadYsh(arg, arg_r, cmd_val)
414
415 if cmd_val.proc_args:
416 raise error.Usage(
417 "doesn't accept typed args without --all, or --num-bytes",
418 cmd_val.proc_args.typed_args.left)
419
420 if arg.t >= 0.0:
421 if arg.t != 0.0:
422 e_die("read -t isn't implemented (except t=0)")
423 else:
424 return 0 if pyos.InputAvailable(STDIN_FILENO) else 1
425
426 bits = 0
427 if self.stdin_.isatty():
428 # -d and -n should be unbuffered
429 if arg.d is not None or mops.BigTruncate(arg.n) >= 0:
430 bits |= pyos.TERM_ICANON
431 if arg.s: # silent
432 bits |= pyos.TERM_ECHO
433
434 if arg.p is not None: # only if tty
435 mylib.Stderr().write(arg.p)
436
437 if bits == 0:
438 status = self._Read(arg, names)
439 else:
440 with ctx_TermAttrs(STDIN_FILENO, ~bits):
441 status = self._Read(arg, names)
442 return status
443
444 def _Read(self, arg, names):
445 # type: (arg_types.read, List[str]) -> int
446
447 # read a certain number of bytes, NOT respecting delimiter (-1 means
448 # unset)
449 arg_N = mops.BigTruncate(arg.N)
450 if arg_N >= 0:
451 s = _ReadN(arg_N, self.cmd_ev)
452
453 if len(names):
454 name = names[0] # ignore other names
455
456 # Clear extra names, as bash does
457 for i in xrange(1, len(names)):
458 state.BuiltinSetString(self.mem, names[i], '')
459 else:
460 name = 'REPLY' # default variable name
461
462 state.BuiltinSetString(self.mem, name, s)
463
464 # Did we read all the bytes we wanted?
465 return 0 if len(s) == arg_N else 1
466
467 do_split = False
468
469 if len(names):
470 do_split = True # read myvar does word splitting
471 else:
472 # read without args does NOT split, and fills in $REPLY
473 names.append('REPLY')
474
475 if arg.a is not None:
476 max_results = 0 # array can hold all parts
477 do_split = True
478 else:
479 # Assign one part to each variable name; leftovers are assigned to
480 # the last name
481 max_results = len(names)
482
483 if arg.Z: # -0 is synonym for IFS= read -r -d ''
484 do_split = False
485 raw = True
486 delim_byte = 0
487 else:
488 raw = arg.r
489 if arg.d is not None:
490 if len(arg.d):
491 delim_byte = ord(arg.d[0])
492 else:
493 delim_byte = 0 # -d '' delimits by NUL
494 else:
495 delim_byte = pyos.NEWLINE_CH # read a line
496
497 # Read MORE THAN ONE line for \ line continuation (and not read -r)
498 parts = [] # type: List[mylib.BufWriter]
499 join_next = False
500 status = 0
501 while True:
502 chunk, eof = _ReadPortion(delim_byte, mops.BigTruncate(arg.n),
503 self.cmd_ev)
504
505 if eof:
506 # status 1 to terminate loop. (This is true even though we set
507 # variables).
508 status = 1
509
510 #log('LINE %r', chunk)
511 if len(chunk) == 0:
512 break
513
514 spans = self.splitter.SplitForRead(chunk, not raw, do_split)
515 done, join_next = _AppendParts(chunk, spans, max_results,
516 join_next, parts)
517
518 #log('PARTS %s continued %s', parts, continued)
519 if done:
520 break
521
522 entries = [buf.getvalue() for buf in parts]
523 num_parts = len(entries)
524 if arg.a is not None:
525 state.BuiltinSetArray(self.mem, arg.a, entries)
526 else:
527 for i in xrange(max_results):
528 if i < num_parts:
529 s = entries[i]
530 else:
531 s = '' # if there are too many variables
532 var_name = names[i]
533 #log('read: %s = %s', var_name, s)
534 state.BuiltinSetString(self.mem, var_name, s)
535
536 return status