Author: Charles Plessy <charles-debian-nospam@plessy.org>
License: public domain.
Description: Gives a default value to par_file so that the environment variable 
             DIALIGN2_DIR is optional

--- dialign-2.2.1.orig/src/dialign.c
+++ dialign-2.2.1/src/dialign.c
@@ -296,10 +296,13 @@
 
  if ((par_file = getenv(dialign_dir)) == NULL)
    {
-     printf("\n \n \n    Please set the environmentvariable DIALIGN2_DIR \n");
-     printf("    as described in the README file \n"); 
-     exit(1);
-   }
+	   par_file = "/usr/share/dialign/" ; /* Default value for Debian, makes the environment variable optional */
+	
+/*     printf("\n \n \n    Please set the environmentvariable DIALIGN2_DIR \n");
+ *    printf("    as described in the README file \n"); 
+ *    exit(1);
+ */
+ }
 
  argnum = argc;
 
@@ -523,6 +526,7 @@
    printf(" to a directory containing the files \n\n");
    printf("   BLOSUM \n   tp400_dna\n   tp400_prot \n   tp400_trans \n\n" );
    printf(" These files should be contained in the DIALIGN package \n\n\n" ) ;
+   printf(" See /usr/share/doc/dialign/README.Debian for more details \n" ) ;
    exit(1) ;