mirror of https://github.com/python/cpython
102 lines
2.1 KiB
Python
102 lines
2.1 KiB
Python
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# Conversions to/from quoted-printable transport encoding as per RFC-XXXX
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# (Dec 1991 version).
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ESCAPE = '='
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MAXLINESIZE = 76
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HEX = '0123456789ABCDEF'
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def needsquoting(c, quotetabs):
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if c == '\t':
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return not quotetabs
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return c == ESCAPE or not(' ' <= c <= '~')
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def quote(c):
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if c == ESCAPE:
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return ESCAPE * 2
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else:
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i = ord(c)
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return ESCAPE + HEX[i/16] + HEX[i%16]
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def encode(input, output, quotetabs):
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while 1:
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line = input.readline()
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if not line: break
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new = ''
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last = line[-1:]
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if last == '\n': line = line[:-1]
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else: last = ''
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prev = ''
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for c in line:
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if needsquoting(c, quotetabs):
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c = quote(c)
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if len(new) + len(c) >= MAXLINESIZE:
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output.write(new + ESCAPE + '\n')
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new = ''
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new = new + c
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prev = c
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if prev in (' ', '\t'):
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output.write(new + ESCAPE + '\n\n')
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else:
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output.write(new + '\n')
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def decode(input, output):
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new = ''
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while 1:
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line = input.readline()
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if not line: break
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i, n = 0, len(line)
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if n > 0 and line[n-1] == '\n':
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partial = 0; n = n-1
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# Strip trailing whitespace
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while n > 0 and line[n-1] in (' ', '\t'):
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n = n-1
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else:
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partial = 1
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while i < n:
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c = line[i]
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if c <> ESCAPE:
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new = new + c; i = i+1
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elif i+1 == n and not partial:
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partial = 1; break
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elif i+1 < n and line[i+1] == ESCAPE:
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new = new + ESCAPE; i = i+2
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elif i+2 < n and ishex(line[i+1]) and ishex(line[i+2]):
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new = new + chr(unhex(line[i+1:i+3])); i = i+3
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else: # Bad escape sequence -- leave it in
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new = new + c; i = i+1
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if not partial:
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output.write(new + '\n')
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new = ''
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if new:
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output.write(new)
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def ishex(c):
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return '0' <= c <= '9' or 'a' <= c <= 'f' or 'A' <= c <= 'F'
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def unhex(s):
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bits = 0
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for c in s:
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if '0' <= c <= '9':
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i = ord('0')
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elif 'a' <= c <= 'f':
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i = ord('a')-10
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elif 'A' <= c <= 'F':
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i = ord('A')-10
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else:
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break
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bits = bits*16 + (ord(c) - i)
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return bits
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def test():
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import sys
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if sys.argv[1:]:
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if sys.argv[1] == '-t': # Quote tabs
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encode(sys.stdin, sys.stdout, 1)
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else:
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decode(sys.stdin, sys.stdout)
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else:
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encode(sys.stdin, sys.stdout, 0)
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if __name__ == '__main__':
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main()
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