summaryrefslogtreecommitdiffstats
path: root/Lib/quopri.py
blob: 55608d12061bbea7c5c03d8c2b7f60b96a2b7a4e (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
# 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
	import getopt
	try:
	    opts, args = getopt.getopt(sys.argv[1:], 'td')
	except getopt.error, msg:
	    sys.stdout = sys.stderr
	    print msg
	    print "usage: quopri [-t | -d] [file] ..."
	    print "-t: quote tabs"
	    print "-d: decode; default encode"
	    sys.exit(2)
	deco = 0
	tabs = 0
	for o, a in opts:
	    if o == '-t': tabs = 1
	    if o == '-d': deco = 1
	if tabs and deco:
	    sys.stdout = sys.stderr
	    print "-t and -d are mutually exclusive"
	    sys.exit(2)
	if not args: args = ['-']
	sts = 0
	for file in args:
	    if file == '-':
		fp = sys.stdin
	    else:
		try:
		    fp = open(file)
		except IOError, msg:
		    sys.stderr.write("%s: can't open (%s)\n" % (file, msg))
		    sts = 1
		    continue
	    if deco:
		decode(fp, sys.stdout)
	    else:
		encode(fp, sys.stdout, tabs)
	    if fp is not sys.stdin:
		fp.close()
	if sts:
	    sys.exit(sts)

if __name__ == '__main__':
	test()