voussoirkit/voussoirkit/pipeable.py
2020-02-17 22:58:26 -08:00

105 lines
2.9 KiB
Python

# import pyperclip moved to stay lazy.
import sys
builtin_input = input
CLIPBOARD_STRINGS = ['!c', '!clip', '!clipboard']
INPUT_STRINGS = ['!i', '!in', '!input', '!stdin']
EOF = '\x1a'
IN_PIPE = not sys.stdin.isatty()
OUT_PIPE = not sys.stdout.isatty()
class PipeableException(Exception):
pass
class NoArguments(PipeableException):
pass
def multi_line_input(prompt=None):
'''
Yield multiple lines of input from the user, until they submit EOF.
EOF is usually Ctrl+D on linux and Ctrl+Z on windows.
The prompt is only shown for non-pipe situations, so you do not need to
adjust your `prompt` argument for pipe/non-pipe usage.
'''
if prompt is not None and not IN_PIPE:
sys.stderr.write(prompt)
sys.stderr.flush()
while True:
line = sys.stdin.readline()
parts = line.split(EOF)
line = parts[0]
has_eof = len(parts) > 1
# Note that just by hitting enter you always get \n, so this does NOT
# mean that input finishes by submitting a blank line! It means that you
# submitted EOF as the first character of a line, so there was nothing
# in parts[0]. If EOF is in the middle of the line we'll still yield the
# first bit before breaking the loop.
if line == '':
break
line = line.rstrip('\n')
yield line
if has_eof:
break
def input(arg=None, *, input_prompt=None, skip_blank=False, strip=False):
if arg is not None:
arg_lower = arg.lower()
if arg is None:
if IN_PIPE:
lines = multi_line_input()
else:
raise ValueError(arg)
elif arg_lower in INPUT_STRINGS:
lines = multi_line_input(prompt=input_prompt)
if not IN_PIPE:
# Wait until the user finishes all their lines before continuing.
# The caller might be processing + printing these lines in a loop
# and it would be weird if they start outputting before the user has
# finished inputting.
lines = list(lines)
elif arg_lower in CLIPBOARD_STRINGS:
import pyperclip
lines = pyperclip.paste().splitlines()
else:
lines = arg.splitlines()
for line in lines:
if strip:
line = line.strip()
if skip_blank and not line:
continue
yield line
def output(line, end='\n'):
sys.stdout.write(line)
if not line.endswith(end):
sys.stdout.write(end)
if not OUT_PIPE:
sys.stdout.flush()
def go(args=None, *input_args, **input_kwargs):
if args is None:
args = sys.argv[1:]
if not args:
# There are no arguments, and...
if IN_PIPE:
# we are being piped to, so read the pipe.
args = [INPUT_STRINGS[0]]
else:
# we are on the terminal, so cry for help.
raise NoArguments()
for arg in args:
yield from input(arg, *input_args, **input_kwargs)