374 cron should send more useful mail
Reviewed by: Richard Lowe <richlowe@richlowe.net>

*** 19,28 ****
--- 19,30 ----
   * CDDL HEADER END
   */
  /*
   * Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
   * Use is subject to license terms.
+  *
+  * Copyright 2013 Joshua M. Clulow <josh@sysmgr.org>
   */
  
  /*      Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T */
  /*        All Rights Reserved   */
  
*** 143,153 ****
  error for each of your commands."
  
  #define CLOCK_DRIFT     "clock time drifted backwards after event!\n"
  #define PIDERR          "unexpected pid returned %d (ignored)"
  #define CRONTABERR      "Subject: Your crontab file has an error in it\n\n"
- #define CRONOUT         "Subject: Output from \"cron\" command\n\n"
  #define MALLOCERR       "out of space, cannot create new string\n"
  
  #define DIDFORK didfork
  #define NOFORK !didfork
  
--- 145,154 ----
*** 2709,2718 ****
--- 2710,2720 ----
          FILE    *st;
          struct utsname  name;
          int     nbytes;
          char    iobuf[BUFSIZ];
          char    *cmd;
+         char    *lowname = (pr->jobtype == CRONEVENT ? "cron" : "at");
  
          (void) uname(&name);
          if ((ruser_ids = getpwnam(p->name)) == NULL)
                  exit(0);
          (void) setuid(ruser_ids->pw_uid);
*** 2722,2756 ****
          mailpipe = popen(cmd, "w");
          free(cmd);
          if (mailpipe == NULL)
                  exit(127);
          (void) fprintf(mailpipe, "To: %s\n", p->name);
!         if (pr->jobtype == CRONEVENT) {
!                 (void) fprintf(mailpipe, CRONOUT);
!                 (void) fprintf(mailpipe, "Your \"cron\" job on %s\n",
!                     name.nodename);
!                 if (pr->jobname != NULL) {
!                         (void) fprintf(mailpipe, "%s\n\n", pr->jobname);
!                 }
!         } else {
!                 (void) fprintf(mailpipe, "Subject: Output from \"at\" job\n\n");
!                 (void) fprintf(mailpipe, "Your \"at\" job on %s\n",
!                     name.nodename);
!                 if (pr->jobname != NULL) {
!                         (void) fprintf(mailpipe, "\"%s\"\n\n", pr->jobname);
!                 }
!         }
!         /* Tmp. file is fopen'ed w/ "r",  secure open */
          if (filesize > 0 &&
              (st = fopen(pr->outfile, "r")) != NULL) {
-                 (void) fprintf(mailpipe,
-                     "produced the following output:\n\n");
                  while ((nbytes = fread(iobuf, sizeof (char), BUFSIZ, st)) != 0)
                          (void) fwrite(iobuf, sizeof (char), nbytes, mailpipe);
                  (void) fclose(st);
          } else {
!                 (void) fprintf(mailpipe, "completed.\n");
          }
          (void) pclose(mailpipe);
          exit(0);
  }
  
--- 2724,2767 ----
          mailpipe = popen(cmd, "w");
          free(cmd);
          if (mailpipe == NULL)
                  exit(127);
          (void) fprintf(mailpipe, "To: %s\n", p->name);
!         (void) fprintf(mailpipe, "Subject: %s <%s@%s> %s\n",
!             (pr->jobtype == CRONEVENT ? "Cron" : "At"),
!             p->name, name.nodename, pr->jobname);
! 
!         /*
!          * RFC3834 (Section 5) defines the Auto-Submitted header to prevent
!          * vacation replies, et al, from being sent in response to
!          * machine-generated mail.
!          */
!         (void) fprintf(mailpipe, "Auto-Submitted: auto-generated\n");
! 
!         /*
!          * Additional headers for mail filtering and diagnostics:
!          */
!         (void) fprintf(mailpipe, "X-Mailer: cron (%s %s)\n", name.sysname,
!             name.release);
!         (void) fprintf(mailpipe, "X-Cron-User: %s\n", p->name);
!         (void) fprintf(mailpipe, "X-Cron-Host: %s\n", name.nodename);
!         (void) fprintf(mailpipe, "X-Cron-Job-Name: %s\n", pr->jobname);
!         (void) fprintf(mailpipe, "X-Cron-Job-Type: %s\n", lowname);
! 
!         /*
!          * Message Body:
!          *
!          * (Temporary file is fopen'ed with "r", secure open.)
!          */
!         (void) fprintf(mailpipe, "\n");
          if (filesize > 0 &&
              (st = fopen(pr->outfile, "r")) != NULL) {
                  while ((nbytes = fread(iobuf, sizeof (char), BUFSIZ, st)) != 0)
                          (void) fwrite(iobuf, sizeof (char), nbytes, mailpipe);
                  (void) fclose(st);
          } else {
!                 (void) fprintf(mailpipe, "Job completed with no output.\n");
          }
          (void) pclose(mailpipe);
          exit(0);
  }