1 files changed, 4 insertions, 2 deletions
diff --git a/sum2.awk b/sum2.awk
index 979d133..694c047 100644
--- a/sum2.awk
+++ b/sum2.awk
@@ -3,7 +3,9 @@
 ### sum2.awk, print column sums
 # check that each line has the same number of fields as line one
 
-NR==1 { nf_max = NF }
+BEGIN { OFS = FS }
+
+NR == 1 { nf_max = NF }
 
 {
     for (i=1; i<=NF; i++)
@@ -13,6 +15,6 @@ NR==1 { nf_max = NF }
 }
 
 END {
-    for (i=1; i<=NF; i++)
+    for (i=1; i<=nf_max; i++)
         printf(OFMT "%s", sum[i], i < nf_max ? OFS : ORS)
 }