mirror of
https://github.com/littlefs-project/littlefs.git
synced 2025-10-16 14:36:37 +08:00
9507e6243c
- Changed multi-field flags to action=append instead of comma-separated. - Dropped short-names for geometries/powerlosses - Renamed -Pexponential -> -Plog - Allowed omitting the 0 for -W0/-H0/-n0 and made -j0 consistent - Better handling of --xlim/--ylim
146 lines
4.0 KiB
Python
Executable File
146 lines
4.0 KiB
Python
Executable File
#!/usr/bin/env python3
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#
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# Efficiently displays the last n lines of a file/pipe.
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#
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# Example:
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# ./scripts/tailpipe.py trace -n5
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#
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# Copyright (c) 2022, The littlefs authors.
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# SPDX-License-Identifier: BSD-3-Clause
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#
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import collections as co
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import io
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import os
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import shutil
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import sys
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import time
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def openio(path, mode='r'):
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if path == '-':
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if mode == 'r':
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return os.fdopen(os.dup(sys.stdin.fileno()), 'r')
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else:
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return os.fdopen(os.dup(sys.stdout.fileno()), 'w')
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else:
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return open(path, mode)
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class LinesIO:
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def __init__(self, maxlen=None):
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self.maxlen = maxlen
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self.lines = co.deque(maxlen=maxlen)
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self.tail = io.StringIO()
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# trigger automatic sizing
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if maxlen == 0:
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self.resize(0)
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def write(self, s):
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# note using split here ensures the trailing string has no newline
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lines = s.split('\n')
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if len(lines) > 1 and self.tail.getvalue():
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self.tail.write(lines[0])
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lines[0] = self.tail.getvalue()
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self.tail = io.StringIO()
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self.lines.extend(lines[:-1])
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if lines[-1]:
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self.tail.write(lines[-1])
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def resize(self, maxlen):
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self.maxlen = maxlen
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if maxlen == 0:
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maxlen = shutil.get_terminal_size((80, 5))[1]
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if maxlen != self.lines.maxlen:
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self.lines = co.deque(self.lines, maxlen=maxlen)
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last_lines = 1
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def draw(self):
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# did terminal size change?
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if self.maxlen == 0:
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self.resize(0)
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# first thing first, give ourself a canvas
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while LinesIO.last_lines < len(self.lines):
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sys.stdout.write('\n')
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LinesIO.last_lines += 1
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for j, line in enumerate(self.lines):
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# move cursor, clear line, disable/reenable line wrapping
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sys.stdout.write('\r')
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if len(self.lines)-1-j > 0:
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sys.stdout.write('\x1b[%dA' % (len(self.lines)-1-j))
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sys.stdout.write('\x1b[K')
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sys.stdout.write('\x1b[?7l')
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sys.stdout.write(line)
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sys.stdout.write('\x1b[?7h')
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if len(self.lines)-1-j > 0:
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sys.stdout.write('\x1b[%dB' % (len(self.lines)-1-j))
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sys.stdout.flush()
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def main(path='-', *, lines=5, cat=False, sleep=0.01, keep_open=False):
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if cat:
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ring = sys.stdout
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else:
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ring = LinesIO(lines)
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ptime = time.time()
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try:
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while True:
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with openio(path) as f:
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for line in f:
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ring.write(line)
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# need to redraw?
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if not cat and time.time()-ptime >= sleep:
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ring.draw()
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ptime = time.time()
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if not keep_open:
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break
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# don't just flood open calls
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time.sleep(sleep or 0.1)
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except KeyboardInterrupt:
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pass
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if not cat:
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sys.stdout.write('\n')
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if __name__ == "__main__":
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import sys
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import argparse
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parser = argparse.ArgumentParser(
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description="Efficiently displays the last n lines of a file/pipe.")
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parser.add_argument(
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'path',
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nargs='?',
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help="Path to read from.")
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parser.add_argument(
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'-n', '--lines',
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nargs='?',
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type=lambda x: int(x, 0),
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const=0,
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help="Show this many lines of history. 0 uses the terminal height. "
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"Defaults to 5.")
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parser.add_argument(
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'-z', '--cat',
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action='store_true',
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help="Pipe directly to stdout.")
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parser.add_argument(
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'-s', '--sleep',
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type=float,
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help="Seconds to sleep between reads. Defaults to 0.01.")
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parser.add_argument(
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'-k', '--keep-open',
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action='store_true',
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help="Reopen the pipe on EOF, useful when multiple "
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"processes are writing.")
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sys.exit(main(**{k: v
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for k, v in vars(parser.parse_intermixed_args()).items()
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if v is not None}))
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