Guido van Rossum | 56f78d9 | 1997-05-08 23:11:04 +0000 | [diff] [blame^] | 1 | # Conversions to/from quoted-printable transport encoding as per RFC-1521 |
Guido van Rossum | f194546 | 1995-06-14 23:43:44 +0000 | [diff] [blame] | 2 | # (Dec 1991 version). |
| 3 | |
| 4 | ESCAPE = '=' |
| 5 | MAXLINESIZE = 76 |
| 6 | HEX = '0123456789ABCDEF' |
| 7 | |
| 8 | def needsquoting(c, quotetabs): |
| 9 | if c == '\t': |
| 10 | return not quotetabs |
| 11 | return c == ESCAPE or not(' ' <= c <= '~') |
| 12 | |
| 13 | def quote(c): |
| 14 | if c == ESCAPE: |
| 15 | return ESCAPE * 2 |
| 16 | else: |
| 17 | i = ord(c) |
| 18 | return ESCAPE + HEX[i/16] + HEX[i%16] |
| 19 | |
| 20 | def encode(input, output, quotetabs): |
| 21 | while 1: |
| 22 | line = input.readline() |
| 23 | if not line: break |
| 24 | new = '' |
| 25 | last = line[-1:] |
| 26 | if last == '\n': line = line[:-1] |
| 27 | else: last = '' |
| 28 | prev = '' |
| 29 | for c in line: |
| 30 | if needsquoting(c, quotetabs): |
| 31 | c = quote(c) |
| 32 | if len(new) + len(c) >= MAXLINESIZE: |
| 33 | output.write(new + ESCAPE + '\n') |
| 34 | new = '' |
| 35 | new = new + c |
| 36 | prev = c |
| 37 | if prev in (' ', '\t'): |
| 38 | output.write(new + ESCAPE + '\n\n') |
| 39 | else: |
| 40 | output.write(new + '\n') |
| 41 | |
| 42 | def decode(input, output): |
| 43 | new = '' |
| 44 | while 1: |
| 45 | line = input.readline() |
| 46 | if not line: break |
| 47 | i, n = 0, len(line) |
| 48 | if n > 0 and line[n-1] == '\n': |
| 49 | partial = 0; n = n-1 |
| 50 | # Strip trailing whitespace |
| 51 | while n > 0 and line[n-1] in (' ', '\t'): |
| 52 | n = n-1 |
| 53 | else: |
| 54 | partial = 1 |
| 55 | while i < n: |
| 56 | c = line[i] |
| 57 | if c <> ESCAPE: |
| 58 | new = new + c; i = i+1 |
| 59 | elif i+1 == n and not partial: |
| 60 | partial = 1; break |
| 61 | elif i+1 < n and line[i+1] == ESCAPE: |
| 62 | new = new + ESCAPE; i = i+2 |
| 63 | elif i+2 < n and ishex(line[i+1]) and ishex(line[i+2]): |
| 64 | new = new + chr(unhex(line[i+1:i+3])); i = i+3 |
| 65 | else: # Bad escape sequence -- leave it in |
| 66 | new = new + c; i = i+1 |
| 67 | if not partial: |
| 68 | output.write(new + '\n') |
| 69 | new = '' |
| 70 | if new: |
| 71 | output.write(new) |
| 72 | |
| 73 | def ishex(c): |
| 74 | return '0' <= c <= '9' or 'a' <= c <= 'f' or 'A' <= c <= 'F' |
| 75 | |
| 76 | def unhex(s): |
| 77 | bits = 0 |
| 78 | for c in s: |
| 79 | if '0' <= c <= '9': |
| 80 | i = ord('0') |
| 81 | elif 'a' <= c <= 'f': |
| 82 | i = ord('a')-10 |
| 83 | elif 'A' <= c <= 'F': |
| 84 | i = ord('A')-10 |
| 85 | else: |
| 86 | break |
| 87 | bits = bits*16 + (ord(c) - i) |
| 88 | return bits |
| 89 | |
| 90 | def test(): |
| 91 | import sys |
Guido van Rossum | 54c1510 | 1995-09-18 21:49:24 +0000 | [diff] [blame] | 92 | import getopt |
| 93 | try: |
| 94 | opts, args = getopt.getopt(sys.argv[1:], 'td') |
| 95 | except getopt.error, msg: |
| 96 | sys.stdout = sys.stderr |
| 97 | print msg |
| 98 | print "usage: quopri [-t | -d] [file] ..." |
| 99 | print "-t: quote tabs" |
| 100 | print "-d: decode; default encode" |
| 101 | sys.exit(2) |
| 102 | deco = 0 |
| 103 | tabs = 0 |
| 104 | for o, a in opts: |
| 105 | if o == '-t': tabs = 1 |
| 106 | if o == '-d': deco = 1 |
| 107 | if tabs and deco: |
| 108 | sys.stdout = sys.stderr |
| 109 | print "-t and -d are mutually exclusive" |
| 110 | sys.exit(2) |
| 111 | if not args: args = ['-'] |
| 112 | sts = 0 |
| 113 | for file in args: |
| 114 | if file == '-': |
| 115 | fp = sys.stdin |
| 116 | else: |
| 117 | try: |
| 118 | fp = open(file) |
| 119 | except IOError, msg: |
| 120 | sys.stderr.write("%s: can't open (%s)\n" % (file, msg)) |
| 121 | sts = 1 |
| 122 | continue |
| 123 | if deco: |
| 124 | decode(fp, sys.stdout) |
| 125 | else: |
| 126 | encode(fp, sys.stdout, tabs) |
| 127 | if fp is not sys.stdin: |
| 128 | fp.close() |
| 129 | if sts: |
| 130 | sys.exit(sts) |
Guido van Rossum | f194546 | 1995-06-14 23:43:44 +0000 | [diff] [blame] | 131 | |
| 132 | if __name__ == '__main__': |
Guido van Rossum | 54c1510 | 1995-09-18 21:49:24 +0000 | [diff] [blame] | 133 | test() |