diff -r 6823dddf9cf1 -r e7437085e589 Admin/Isabelle_app/Isabelle.c
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/Admin/Isabelle_app/Isabelle.c	Tue Jan 26 21:33:52 2021 +0100
@@ -0,0 +1,45 @@
+/*  Author:     Makarius
+
+Main Isabelle application executable.
+*/
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <sys/types.h>
+#include <unistd.h>
+#include <libgen.h>
+
+
+static void fail(const char *msg)
+{
+  fprintf(stderr, "%s\n", msg);
+  exit(2);
+}
+
+
+int main(int argc, char *argv[])
+{
+  char **cmd_line = NULL, *cmd = NULL, *dcmd = NULL, *dname = NULL;
+  int i = 0;
+
+  dcmd = strdup(argv[0]);
+  if (dcmd == NULL) fail("Failed to allocate memory");
+
+  dname = dirname(dcmd);
+
+  cmd_line = malloc(sizeof(char *) * (argc + 1));
+  if (cmd_line == NULL) fail("Failed to allocate memory");
+
+  cmd = malloc(strlen(dname) + strlen("/lib/scripts/Isabelle_app") + 1);
+  if (cmd == NULL) fail("Failed to allocate memory");
+  sprintf(cmd, "%s/lib/scripts/Isabelle_app", dname);
+
+  cmd_line[0] = cmd;
+  for (i = 1; i < argc; i++) cmd_line[i] = argv[i];
+  cmd_line[argc] = NULL;
+
+  execvp(cmd, cmd_line);
+  fprintf(stderr, "Failed to execute application script \"%s\"\n", cmd);
+  exit(2);
+}