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
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
|
From: Robert Luberda <robert@debian.org>
Date: Thu, 13 Apr 2017 23:39:39 +0200
Subject: Add MIME headers unless set by user
Generate the three following headers by default:
MIME-Version: 1.0
Content-Type: text/plain; charset="<current charset from $LC_CTYPE>"
Content-Transfer-Encoding: 8bit
However allow a user to override each of them with the -a flag.
Example:
bsd-mailx -a "Content-Type: text/html; charset=UTF-8"
uses the above user-provided Content-Type, but still adds
the default MIME-Version and Content-Transfer-Encoding headers.
Bugs-Debian: https://bugs.debian.org/859935
---
mail.1 | 28 +++++++++++++++++++++++++++-
main.c | 4 ++++
send.c | 43 +++++++++++++++++++++++++++++++++++++++++++
3 files changed, 74 insertions(+), 1 deletion(-)
diff --git a/mail.1 b/mail.1
index b1bde8f..88949be 100644
--- a/mail.1
+++ b/mail.1
@@ -67,7 +67,13 @@ The options are as follows:
.Bl -tag -width Ds
.It Fl a
Specify additional header fields on the command line such as "X-Loop:
-foo@bar" etc. You have to use quotes if the string contains spaces.
+foo@bar" etc.
+It can be also used to override MIME headers
+.Nm mail
+adds by default to each outgoing mail, see
+.Sx Character sets and MIME
+below.
+You have to use quotes if the string contains spaces.
This argument may be specified more than once, the headers will then
be concatenated.
.It Fl b Ar bcc-addr
@@ -366,6 +372,26 @@ If the
.Ic expandaddr
option is not set (the default), no expansion is performed and
the recipient is treated as a local or network mail address.
+.Ss Character sets and MIME
+Generally
+.Nm mail
+does not handle neither different character sets nor any other MIME
+feature. Especially it does not perform any any conversions between
+character sets while displaying or sending mails.
+.Pp
+Starting from April 2017, however, as a Debian extension this version of
+.Nm mail
+adds a few MIME headers to every outgoing mail in order to indicate
+that the mail is sent as 8-bit plain text data that uses character
+set encoding detected from the current
+.Xr locale 7
+settings.
+The
+.Fl a
+command-line option can be used to override those headers, for example:
+.Dl $ mail -a 'Content-Type: text/plain; charset="ISO-8859-1"'
+sets header indicating legacy character encoding.
+.Pp
.Ss Network mail (ARPA, UUCP, Berknet)
See
.Xr mailaddr 7
diff --git a/main.c b/main.c
index 07ad856..4cba833 100644
--- a/main.c
+++ b/main.c
@@ -34,6 +34,7 @@
#include <fcntl.h>
#include <sys/ioctl.h>
#include "extern.h"
+#include <locale.h>
static void usage(void);
int main(int, char **);
@@ -70,6 +71,9 @@ main(int argc, char **argv)
err(1, "setuid");
}
+ /* Set the current user locale's charset. */
+ setlocale(LC_CTYPE, "");
+
/*
* Set up a reasonable environment.
* Figure out whether we are being run interactively,
diff --git a/send.c b/send.c
index cc75f49..771ecc9 100644
--- a/send.c
+++ b/send.c
@@ -30,6 +30,7 @@
* SUCH DAMAGE.
*/
+#include <langinfo.h>
#include <time.h>
#include "rcv.h"
#include "extern.h"
@@ -558,6 +559,36 @@ infix(struct header *hp, FILE *fi)
rewind(nfi);
return(nfi);
}
+/*
+ * Check if headers (a list separated by new line characters) contains a header
+ * which name is given in the headername argument of length given in headernamelen.
+ */
+static int hasheader(const char* headers, const char* const headername, const size_t headernamelen)
+{
+ while (headers) {
+ /* Skip leading white spaces, including '\n' from
+ * the previous iteration of the loop
+ */
+ while (isspace(*headers))
+ ++headers;
+
+ if (strncasecmp(headers, headername, headernamelen) == 0) {
+ /* Found a match, check if it is followed by ':' */
+ const char* end = headers + headernamelen;
+ /* Permit optional white spaces before ':' */
+ while (isspace(*end) && *end != '\n')
+ ++end;
+
+ if (*end == ':')
+ return 1;
+
+ headers = end; /* Small optimization for the following strchr() call */
+ }
+
+ headers = strchr(headers, '\n'); /* Find start of the next header */
+ }
+ return 0;
+}
/*
* Dump the to, subject, cc header on the
@@ -583,6 +614,18 @@ puthead(struct header *hp, FILE *fo, int w)
fmt("Bcc:", hp->h_bcc, fo, w&GCOMMA), gotcha++;
if (hp->h_header != NULL && w)
fprintf(fo, "%s\n", hp->h_header), gotcha++;
+ if (w)
+ {
+#define ADDHEADER(name, value, ...) if (!hasheader(hp->h_header, name, sizeof(name) - 1)) \
+ fprintf(fo, name ": " value "\n", ##__VA_ARGS__), gotcha++
+
+ const char* const cs = nl_langinfo(CODESET);
+ ADDHEADER("MIME-Version", "1.0");
+ ADDHEADER("Content-Type", "text/plain; charset=\"%s\"",
+ cs && *cs ? cs : "ANSI_X3.4-1968");
+ ADDHEADER("Content-Transfer-Encoding", "8bit");
+#undef ADDHEADER
+ }
if (hp->h_replyto != NULL && w & GREPLYTO)
fprintf(fo, "Reply-To: %s\n", hp->h_replyto), gotcha++;
if (hp->h_inreplyto != NULL && w & GINREPLYTO)
|
