unfold.c
1.55 KB
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
/* GNU Mailutils -- a suite of utilities for electronic mail
Copyright (C) 2009-2012, 2014-2017 Free Software Foundation, Inc.
This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 3 of the License, or (at your option) any later version.
This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General
Public License along with this library. If not, see
<http://www.gnu.org/licenses/>. */
#if HAVE_CONFIG_H
# include <config.h>
#endif
#include <unistd.h>
#include <errno.h>
int
mu_string_unfold (char *text, size_t *plen)
{
char *p, *q;
enum uf_state { uf_init, uf_nl, uf_fold } state = uf_init;
#define ISSPACE(c) (c == '\r' || c == ' ' || c == '\t')
if (!text)
return EINVAL;
for (p = q = text; *q; q++)
{
switch (state)
{
case uf_init:
if (*q == '\n')
state = uf_nl;
else
*p++ = *q;
break;
case uf_nl:
if (ISSPACE (*q))
state = uf_fold;
else
{
state = uf_init;
*p++ = *q;
}
break;
case uf_fold:
if (!ISSPACE (*q))
{
*p++ = ' ';
*p++ = *q;
state = uf_init;
}
break;
}
}
*p++ = 0;
if (plen)
*plen = p - text;
return 0;
}