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anacron: read SENDMAIL variable from anacrontab #135

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anacron: read SENDMAIL variable from anacrontab #135

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02fbcf2
anacron: read SENDMAIL variable from anacrontab
corvus1 Jan 9, 2023
dff6a11
Getting command line parameters is partially working. The regex worked!
corvus1 Jan 12, 2023
e72488b
ugly but works. Check for '-' in parameters. If not found, don't pass.
corvus1 Jan 14, 2023
c06a13d
update anacrontab manpage
corvus1 Jan 16, 2023
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1 change: 1 addition & 0 deletions anacron/global.h
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Original file line number Diff line number Diff line change
Expand Up @@ -30,6 +30,7 @@
#define SYSLOG_FACILITY LOG_CRON
#define EXPLAIN_LEVEL LOG_NOTICE /* informational messages */
#define COMPLAIN_LEVEL LOG_ERR /* error messages */
#define DEBUG DEBUG
#define DEBUG_LEVEL LOG_DEBUG /* only used when DEBUG is defined */

/* Mail interface. (All MTAs should supply this command) */
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46 changes: 39 additions & 7 deletions anacron/runjob.c
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Expand Up @@ -39,6 +39,8 @@

#include <langinfo.h>

#include "matchrx.h"

static int
temp_file(job_rec *jr)
/* Open a temporary file and return its file descriptor */
Expand Down Expand Up @@ -207,6 +209,11 @@ xwait(pid_t pid , int *status)
static void
launch_mailer(job_rec *jr)
{
int r;
char *mailer;
char *mailer_args;
char *mailer_full;

pid_t pid;
struct stat buf;

Expand Down Expand Up @@ -247,13 +254,38 @@ launch_mailer(job_rec *jr)
/* fdflags = fcntl(0, F_GETFL); fdflags &= ~O_APPEND; */
/* fcntl(0, F_SETFL, fdflags ); */

/* Here, I basically mirrored the way /usr/sbin/sendmail is called
* by cron on a Debian system, except for the "-oem" and "-or0s"
* options, which don't seem to be appropriate here.
* Hopefully, this will keep all the MTAs happy. */
execl(SENDMAIL, SENDMAIL, "-FAnacron", "-odi",
jr->mailto, (char *)NULL);
die_e("Can't exec " SENDMAIL);
/* Get SENDMAIL variable from the environment if set.
/* If not, will use the predefined SENDMAIL from global.h */
mailer_full = getenv("SENDMAIL");

if (mailer_full == NULL) {
/* Here, I basically mirrored the way /usr/sbin/sendmail is called
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Here I wouldn't duplicate the execl call but instead assign SENDMAIL to mailer_full if it is NULL.

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Here I wouldn't duplicate the execl call but instead assign SENDMAIL to mailer_full if it is NULL.

I don't know how to do it, without making it into a special case. We need to pass these arguments to sendmail.

* by cron on a Debian system, except for the "-oem" and "-or0s"
* options, which don't seem to be appropriate here.
* Hopefully, this will keep all the MTAs happy. */
execl(SENDMAIL, SENDMAIL, "-FAnacron", "-odi",
jr->mailto, (char *)NULL);
die_e("Can't exec " SENDMAIL);
} else {

/* Splitting into binary path and command line parameters*/

complain("mailer_full - `%s`", mailer_full);

strcat(mailer_full," ");
r = match_rx("(^[^ ]*) (.*)", mailer_full, 2, &mailer, &mailer_args);
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Unfortunately this is more complicated as for executing the mailer via execl the arguments would have to be split. Or perhaps better would be to just allow a few mailer arguments in separate environment variables. SENDMAILARG1 SENDMAILARG2 SENDMAILARG3....

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@corvus1 corvus1 Jan 20, 2023 •
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Unfortunately this is more complicated as for executing the mailer via execl the arguments would have to be split. Or perhaps better would be to just allow a few mailer arguments in separate environment variables. SENDMAILARG1 SENDMAILARG2 SENDMAILARG3....

Is that... even acceptable to shift the task of separating arguments to the user? I mean... that's kinda rude even for me. Is that okay? I mean... it turns out, it's incredibly hard to separate arguments in C.

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It is a problem to properly separate the arguments in C because you'd basically have to re-implement the shell argument separator parser to make it really useful. I.e. you'd have to support at least ", ' as quotes and then you also need to somehow support escaping these quote characters, etc.

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@corvus1 corvus1 Jan 20, 2023 •
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It is a problem to properly separate the arguments in C because you'd basically have to re-implement the shell argument separator parser to make it really useful. I.e. you'd have to support at least ", ' as quotes and then you also need to somehow support escaping these quote characters, etc.

I thought I'd just go for something simple, rudimentary even. Look for " -" and split on that. Maybe even with a regex in a loop. There is something going on there, though. If SENDMAIL variable is longer than "/usr/bin/logger -t anacronmai" by a single character, everything breaks and I get some other string there. As if something overlapped in memory.


complain("mailer - `%s` ", mailer);
complain("mailer_args - `%s`", mailer_args);

if ( strchr(mailer_args, '-') != NULL ) {
execl(mailer, mailer, mailer_args, (char *)NULL);
} else {
execl(mailer, mailer, (char *)NULL);
}

die_e("Can't exec the mailer %s", mailer);
}
}
/* parent */
/* record mailer pid */
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5 changes: 4 additions & 1 deletion man/anacrontab.5
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Expand Up @@ -60,11 +60,14 @@ The
.I RANDOM_DELAY
variable denotes the maximum number of minutes that will be added to the
delay in minutes variable which is specified for each job. A
.I RANDOM_DELAY
set to 12 would therefore add, randomly, between 0 and 12 minutes to the
delay in minutes for each job in that particular anacrontab. When set to
0, no random delay is added.
.PP
.I SENDMAIL
variable allows to assign an alternative mailer program, instead of
default /usr/sbin/sendmail
.PP
If
.I MAILTO
is defined (and non-empty), mail is sent to the specified address,
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