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