commit 03b52640efbd9f8fdd2297740b1c79fa0a1a7652
parent 839a4563e809916ccdd8ebeac1461d8c7ffc62e7
Author: Hiltjo Posthuma <hiltjo@codemadness.org>
Date: Tue, 11 Nov 2025 20:50:06 +0100
sfeed_mbox: add mail headers and other improvements
Note: these changes may cause duplicate messages for existing users in some
use-cases because the Message-ID, From and To header will be different.
Changes:
Add mail headers, they are now only set headers when they have a value and are
non-empty.
These headers are used by rss2email also:
- X-RSS-ID: the item ID.
- X-RSS-TAGS: the category tags, '|' in sfeed(5) is replaced by ','.
- X-RSS-URL: the item link / URL.
Also added:
- X-RSS-Author: the item author.
- X-RSS-Enclosure: the first enclosure.
This allows more convenient filtering in many mail clients.
One can further manipulate the headers using mail tools or awk or a sed
expression for example. For example changing X-Feedname to X-Label etc.
- Change the default From and To header. It does not use the system hostname or
$USER anymore.
Add environment variables with defaults:
$SFEED_MBOX_FROM: <anonymous@localhost>
$SFEED_MBOX_TO: <anonymous@localhost>
- Fixes: The To header could contain characters that are invalid for the To
header as well.
- Fixes: The Message-ID field could contain spaces or invalid characters. Now
it is "@newsfeed.local".
Diffstat:
| M | sfeed_mbox.1 | | | 18 | +++++++++++++++++- |
| M | sfeed_mbox.c | | | 73 | +++++++++++++++++++++++++++++++++++++++++++++++++++---------------------- |
2 files changed, 68 insertions(+), 23 deletions(-)
diff --git a/sfeed_mbox.1 b/sfeed_mbox.1
@@ -1,4 +1,4 @@
-.Dd October 27, 2024
+.Dd October 10, 2025
.Dt SFEED_MBOX 1
.Os
.Sh NAME
@@ -35,6 +35,16 @@ To make further filtering simpler some custom headers are set:
.It X-Feedname
The feed name, this is the basename of the feed
.Ar file .
+.It X-RSS-Author
+Item author, if it is set.
+.It X-RSS-Enclosure
+Item, first enclosure, if it is set.
+.It X-RSS-ID
+RSS item GUID or Atom id, if it is set.
+.It X-RSS-TAGS
+Category field, the '|' separator is replaced by a comma (',').
+.It X-RSS-URL
+Item link, if it is set.
.El
.Sh ENVIRONMENT VARIABLES
.Bl -tag -width Ds
@@ -43,6 +53,12 @@ Include the content.
This can be insecure for some of the mail clients that interpret HTML code in
an unsafe way.
By default this is set to "0".
+.It Ev SFEED_MBOX_FROM
+Override the host for the "From" header.
+The default is "anonymous@localhost".
+.It Ev SFEED_MBOX_TO
+Override the user for the "To" header.
+The default is "anonymous@localhost".
.El
.Sh EXIT STATUS
.Ex -std
diff --git a/sfeed_mbox.c b/sfeed_mbox.c
@@ -2,14 +2,17 @@
#include <stdlib.h>
#include <string.h>
#include <time.h>
-#include <unistd.h>
#include "util.h"
static char *line;
static size_t linesize;
-static char host[256], *user, dtimebuf[32], mtimebuf[32];
-static int usecontent = 0; /* env variable: $SFEED_MBOX_CONTENT */
+static char dtimebuf[32], mtimebuf[32];
+
+/* env variables: $SFEED_MBOX_FROM and $SFEED_MBOX_TO */
+static char *from = "<anonymous@localhost>", *to = "<anonymous@localhost>";
+/* env variable: $SFEED_MBOX_CONTENT */
+static int usecontent = 0;
static unsigned long long
djb2(unsigned char *s, unsigned long long hash)
@@ -21,18 +24,29 @@ djb2(unsigned char *s, unsigned long long hash)
return hash;
}
+static void
+printtags(const char *s)
+{
+ for (; *s; s++) {
+ if (*s == '|')
+ putchar(',');
+ else
+ putchar(*s);
+ }
+}
+
/* Unescape / decode fields printed by string_print_encoded()
* "\\" to "\", "\t", to TAB, "\n" to newline. Other escape sequences are
* ignored: "\z" etc. Mangle "From " in mboxrd style (always prefix >). */
static void
-printcontent(const char *s, FILE *fp)
+printcontent(const char *s)
{
escapefrom:
for (; *s == '>'; s++)
- putc('>', fp);
+ putchar('>');
/* escape "From ", mboxrd-style. */
if (!strncmp(s, "From ", 5))
- putc('>', fp);
+ putchar('>');
for (; *s; s++) {
switch (*s) {
@@ -42,15 +56,15 @@ escapefrom:
s++;
switch (*s) {
case 'n':
- putc('\n', fp);
+ putchar('\n');
s++;
goto escapefrom;
- case '\\': putc('\\', fp); break;
- case 't': putc('\t', fp); break;
+ case '\\': putchar('\\'); break;
+ case 't': putchar('\t'); break;
}
break;
default:
- putc(*s, fp); break;
+ putchar(*s); break;
}
}
}
@@ -84,13 +98,13 @@ printfeed(FILE *fp, const char *feedname)
printf("Date: %s\n", dtimebuf); /* invalid/missing: use current time */
}
- printf("From: %s <anonymous@>\n", fields[FieldAuthor][0] ? fields[FieldAuthor] : feedname);
- printf("To: %s <%s@%s>\n", user, user, host);
+ printf("From: %s\n", from);
+ printf("To: %s\n", to);
printf("Subject: %s\n", fields[FieldTitle]);
- printf("Message-ID: <%s%s%llu@%s>\n",
+ printf("Message-ID: <%s%s%llu@newsfeed.local>\n",
fields[FieldUnixTimestamp],
fields[FieldUnixTimestamp][0] ? "." : "",
- hash, feedname);
+ hash);
ishtml = usecontent && !strcmp(fields[FieldContentType], "html");
if (ishtml)
@@ -98,7 +112,21 @@ printfeed(FILE *fp, const char *feedname)
else
fputs("Content-Type: text/plain; charset=\"utf-8\"\n", stdout);
fputs("Content-Transfer-Encoding: binary\n", stdout);
- printf("X-Feedname: %s\n", feedname);
+ if (feedname[0])
+ printf("X-Feedname: %s\n", feedname);
+ if (fields[FieldAuthor][0])
+ printf("X-RSS-Author: %s\n", fields[FieldAuthor]);
+ if (fields[FieldEnclosure][0])
+ printf("X-RSS-Enclosure: %s\n", fields[FieldEnclosure]);
+ if (fields[FieldId][0])
+ printf("X-RSS-ID: %s\n", fields[FieldId]);
+ if (fields[FieldCategory][0]) {
+ fputs("X-RSS-TAGS: ", stdout);
+ printtags(fields[FieldCategory]);
+ fputs("\n", stdout);
+ }
+ if (fields[FieldLink][0])
+ printf("X-RSS-URL: %s\n", fields[FieldLink]);
fputs("\n", stdout);
if (ishtml) {
@@ -131,7 +159,7 @@ printfeed(FILE *fp, const char *feedname)
xmlencode(fields[FieldLink], stdout);
fputs("\"/>\n", stdout);
}
- printcontent(fields[FieldContent], stdout);
+ printcontent(fields[FieldContent]);
}
fputs("\n\n", stdout);
}
@@ -146,15 +174,16 @@ main(int argc, char *argv[])
char *name, *tmp;
int i;
- if (pledge(argc == 1 ? "stdio" : "stdio rpath", NULL) == -1)
+ if (pledge(argc <= 1 ? "stdio" : "stdio rpath", NULL) == -1)
err(1, "pledge");
if ((tmp = getenv("SFEED_MBOX_CONTENT")))
usecontent = !strcmp(tmp, "1");
- if (!(user = getenv("USER")))
- user = "you";
- if (gethostname(host, sizeof(host)) == -1)
- err(1, "gethostname");
+ if ((tmp = getenv("SFEED_MBOX_FROM")))
+ from = tmp;
+ if ((tmp = getenv("SFEED_MBOX_TO")))
+ to = tmp;
+
if ((now = time(NULL)) == (time_t)-1)
errx(1, "time");
if (!gmtime_r(&now, &tmnow))
@@ -164,7 +193,7 @@ main(int argc, char *argv[])
if (!strftime(dtimebuf, sizeof(dtimebuf), "%a, %d %b %Y %H:%M:%S +0000", &tmnow))
errx(1, "strftime: can't format current time");
- if (argc == 1) {
+ if (argc <= 1) {
printfeed(stdin, "");
checkfileerror(stdin, "<stdin>", 'r');
} else {
