--- joko/Uni/BSArch/01/prime.c	2006/05/13 09:20:36	1.9
+++ joko/Uni/BSArch/01/prime.c	2006/05/13 12:06:38	1.10
@@ -1,4 +1,4 @@
-/* $Id: prime.c,v 1.9 2006/05/13 09:20:36 joko Exp $ */
+/* $Id: prime.c,v 1.10 2006/05/13 12:06:38 joko Exp $ */
 
 #include <stdio.h>
 #include <stdlib.h>
@@ -11,6 +11,7 @@
 
 #define PRINTPRIME(x) if (is_prime(x)) printf("%i\n", x)
 #define PRINTERROR(message) fprintf(stderr, "ERROR: %s\n", message)
+#define PRINTWARNING(message) fprintf(stderr, "WARNING: %s\n", message)
 
 /* check for prime number */
 BOOL is_prime(long int number)
@@ -31,9 +32,10 @@
 /* convert from string to long int, with error checking */
 long int convert_number(const char *nptr) {
 	
-	errno = 0;
 	char * endptr;
 	long int number = strtol(nptr, &endptr, 10);
+
+	errno = 0;
 	
 	/* invalid characters? */
 	if (*endptr != '\0') {
@@ -86,9 +88,37 @@
 		
 		/* (2) file mode: read numbers from file */
 		} else {
-			char entry[11];
-			while (fgets(entry, 11, fp)) {
-				long int number = convert_number(entry);
+			char entry[81];
+			long int number;
+			long int lineno = 0;
+			while (fgets(entry, 81, fp)) {
+				
+				/* count line number (for warnings) */
+				lineno++;
+
+				/* skip empty lines */
+				if (strlen(entry) < 2) continue;
+
+				/* line handling: policy = skip exceeding lines */
+				
+				/* if last char is newline, strip it */
+				if (entry[strlen(entry)-1] == '\n') {
+					entry[strlen(entry)-1] = '\0';
+					
+				/* line exceeds max length */
+				} else {
+					char message[254];
+					snprintf(message, 256, "Line too long (max 80 chars) in line number: %i", lineno);
+					PRINTWARNING(message);
+					
+					/* eat all characters until newline */
+					while (fgetc(fp) != 10);
+					
+					/* skip this line from prime calculation */
+					continue;
+				}
+				
+				number = convert_number(entry);
 				PRINTPRIME(number);
 			}
 			fclose(fp);