? .gdbinit
? cal
Index: cal.c
===================================================================
RCS file: /cvsroot/src/usr.bin/cal/cal.c,v
retrieving revision 1.30
diff -u -p -r1.30 cal.c
--- cal.c	29 Jun 2020 14:01:14 -0000	1.30
+++ cal.c	29 Jun 2020 21:41:49 -0000
@@ -350,6 +350,7 @@ monthrange(int month, int year, int befo
 	int i, row;
 	int days[3][MAXDAYS];
 	char lineout[256];
+	int multirow;
 	int inayear;
 	int newyear;
 	int day_len, week_len, head_sep;
@@ -380,6 +381,8 @@ monthrange(int month, int year, int befo
 		errx(1, "year should be in 1-9999");
 	}
 
+	multirow = (yearly || (1 + before + after > month_per_row));
+
 	year = startyear;
 	month = startmonth;
 	inayear = newyear = (year != endyear || yearly);
@@ -468,7 +471,8 @@ monthrange(int month, int year, int befo
 			}
 			*p = '\0';
 			trim_trailing_spaces(lineout);
-			(void)printf("%s\n", lineout);
+			if (multirow || strlen(lineout))
+				(void)printf("%s\n", lineout);
 		}
 
 		skip = 0;