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-rw-r--r--python/vyos/utils/io.py103
1 files changed, 103 insertions, 0 deletions
diff --git a/python/vyos/utils/io.py b/python/vyos/utils/io.py
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+++ b/python/vyos/utils/io.py
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+# Copyright 2023 VyOS maintainers and contributors <maintainers@vyos.io>
+#
+# 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, see <http://www.gnu.org/licenses/>.
+
+def print_error(str='', end='\n'):
+ """
+ Print `str` to stderr, terminated with `end`.
+ Used for warnings and out-of-band messages to avoid mangling precious
+ stdout output.
+ """
+ import sys
+ sys.stderr.write(str)
+ sys.stderr.write(end)
+ sys.stderr.flush()
+
+def make_progressbar():
+ """
+ Make a procedure that takes two arguments `done` and `total` and prints a
+ progressbar based on the ratio thereof, whose length is determined by the
+ width of the terminal.
+ """
+ import shutil, math
+ col, _ = shutil.get_terminal_size()
+ col = max(col - 15, 20)
+ def print_progressbar(done, total):
+ if done <= total:
+ increment = total / col
+ length = math.ceil(done / increment)
+ percentage = str(math.ceil(100 * done / total)).rjust(3)
+ print_error(f'[{length * "#"}{(col - length) * "_"}] {percentage}%', '\r')
+ # Print a newline so that the subsequent prints don't overwrite the full bar.
+ if done == total:
+ print_error()
+ return print_progressbar
+
+def make_incremental_progressbar(increment: float):
+ """
+ Make a generator that displays a progressbar that grows monotonically with
+ every iteration.
+ First call displays it at 0% and every subsequent iteration displays it
+ at `increment` increments where 0.0 < `increment` < 1.0.
+ Intended for FTP and HTTP transfers with stateless callbacks.
+ """
+ print_progressbar = make_progressbar()
+ total = 0.0
+ while total < 1.0:
+ print_progressbar(total, 1.0)
+ yield
+ total += increment
+ print_progressbar(1, 1)
+ # Ignore further calls.
+ while True:
+ yield
+
+def ask_input(question, default='', numeric_only=False, valid_responses=[]):
+ question_out = question
+ if default:
+ question_out += f' (Default: {default})'
+ response = ''
+ while True:
+ response = input(question_out + ' ').strip()
+ if not response and default:
+ return default
+ if numeric_only:
+ if not response.isnumeric():
+ print("Invalid value, try again.")
+ continue
+ response = int(response)
+ if valid_responses and response not in valid_responses:
+ print("Invalid value, try again.")
+ continue
+ break
+ return response
+
+def ask_yes_no(question, default=False) -> bool:
+ """Ask a yes/no question via input() and return their answer."""
+ from sys import stdout
+ default_msg = "[Y/n]" if default else "[y/N]"
+ while True:
+ try:
+ stdout.write("%s %s " % (question, default_msg))
+ c = input().lower()
+ if c == '':
+ return default
+ elif c in ("y", "ye", "yes"):
+ return True
+ elif c in ("n", "no"):
+ return False
+ else:
+ stdout.write("Please respond with yes/y or no/n\n")
+ except EOFError:
+ stdout.write("\nPlease respond with yes/y or no/n\n")