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-rw-r--r-- | python/vyos/utils/io.py | 103 |
1 files changed, 103 insertions, 0 deletions
diff --git a/python/vyos/utils/io.py b/python/vyos/utils/io.py new file mode 100644 index 000000000..843494855 --- /dev/null +++ b/python/vyos/utils/io.py @@ -0,0 +1,103 @@ +# 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") |