********>BZIP2 Support Update for Carnal in Amber 7
Author: Ross Walker
Date: 3/13/03

Programs: Carnal

Description: Most versions of Linux now include support for the bzip2 method of file compression.
             This typically offers between 10 and 20% higher compression ratios than gzip.
             This patch adds support for bzipped mdcrd files using the bunzip2 program.
             Bzip2 files should have the file extension .bz2

Usage: Apply the following patch to amber7/src/carnal/util.c:

------------------------------------------------------------------------------

*** util.c	Fri Nov 23 00:00:00 2001
--- util.c	Thu Mar 13 13:35:37 2003
@@ -41,6 +41,7 @@
 
 #define COMPRESS	1
 #define GZIP		2
+#define BZIP2		3
 
 char		tok[TOKLEN];
 char		line[TOKLEN];
@@ -206,9 +207,15 @@
 					compressed = GZIP;
 					goto OPEN;
 				}
-				
+				strcpy(&cbuf[length], ".bz2");
+				if (stat(cbuf, &sbuf) != -1) {
+					printf("\tusing %s\n", cbuf);
+					strcat(name, ".bz2");
+					compressed = BZIP2;
+					goto OPEN;
+				}
 				printf("%s: does not exist %s\n", 
-						name, "(nor do .Z or .gz)");
+						name, "(nor do .Z or .gz or .bz2)");
 				return(NULL);
 
 			    case COMPRESS:
@@ -234,6 +241,18 @@
 				name[length-2] = '\0';
 				compressed = 0;
 				goto OPEN;
+			    
+			    case BZIP2:
+				cbuf[length-4] = '\0';
+				if (stat(cbuf, &sbuf) == -1) {
+					printf("%s, %s: does not exist\n", 
+								name, cbuf);
+					return(NULL);
+				}
+				printf("\tusing %s\n", cbuf);
+				name[length-2] = '\0';
+				compressed = 0;
+				goto OPEN;
 			}
 		    }
 		    default:
@@ -273,6 +292,16 @@
 		}
 		break;
 	    }
+	    case BZIP2: {
+		char pcmd[MAXPATHLEN+20];
+
+		sprintf(pcmd, "bunzip2 -c %s", cbuf);
+		if ((fp = popen(pcmd, "r")) == NULL) {
+			perror(pcmd);
+			exit(1);
+		}
+		break;
+	    }
 	    default:
 		printf("programming error in genopen\n");
 		exit(1);
@@ -420,6 +449,18 @@
 		}
 		break;
 	    }
+	    case BZIP2: {
+		char	pcmd[120];
+
+		sprintf(pcmd, "bunzip2 -c %s", name);
+		if (pclose(*file) == -1)
+			perror(name);
+		if ((*file = popen(pcmd, "r")) == NULL) {
+			perror(pcmd);
+			exit(1);
+		}
+		break;
+	    }
 	    default:
 		fprintf(stderr, "programmer error - compression type\n");
 		exit(1);
@@ -463,6 +504,13 @@
 		return(0);
 	if (!strcmp(&name[i-3], ".gz"))
 		return(GZIP);
+	if (i < 5)
+		return(0);
+	if (!strcmp(&name[i-4], ".bz2"))
+	{
+		return(BZIP2);
+		
+	}
 	return(0);
 }