diff -up at-3.1.20/at.c.shell at-3.1.20/at.c

--- at-3.1.20/at.c.shell	2016-07-01 09:47:13.392684445 +0200

+++ at-3.1.20/at.c	2016-07-01 09:48:47.679931959 +0200

@@ -62,11 +62,8 @@

 #include <stdlib.h>

 #include <string.h>

-#ifdef TM_IN_SYS_TIME

 #include <sys/time.h>

-#else

 #include <time.h>

-#endif

 #ifdef HAVE_UNISTD_H

 #include <unistd.h>

@@ -239,6 +236,12 @@ writefile(time_t runtimer, char queue)

     int kill_errno;

     int rc;

     int mailsize = 128;

+    struct timeval tv;

+    struct timezone tz;

+    long int i;

+

+    gettimeofday(&tv, &tz;;

+    srandom(getpid()+tv.tv_usec);

 /* Install the signal handler for SIGINT; terminate after removing the

  * spool file if necessary

@@ -465,6 +468,9 @@ writefile(time_t runtimer, char queue)

     fprintf(fp, " || {\n\t echo 'Execution directory "

 	    "inaccessible' >&2\n\t exit 1\n}\n");

+    i = random();

+    fprintf(fp, "${SHELL:-/bin/sh} << \'marcinDELIMITER%08lx\'\n", i);

+

     istty = isatty(fileno(stdin));

     if (istty) {

 	fprintf(stderr, "at> ");

@@ -480,7 +486,7 @@ writefile(time_t runtimer, char queue)

     if (istty) {

 	fprintf(stderr, "<EOT>\n");

     }

-    fprintf(fp, "\n");

+    fprintf(fp, "marcinDELIMITER%08lx\n", i);

     if (ferror(fp))

 	panic("Output error");

     fflush(fp);