1 files changed, 14 insertions, 5 deletions
diff --git a/sum2.awk b/sum2.awk
index 694c047..4fcf3b6 100644
--- a/sum2.awk
+++ b/sum2.awk
@@ -3,18 +3,27 @@
 ### sum2.awk, print column sums
 # check that each line has the same number of fields as line one
 
-BEGIN { OFS = FS }
 
-NR == 1 { nf_max = NF }
+BEGIN {
+    OFS = FS
+}
+
+
+NR == 1 {
+    for (i=1; i<=NF; i++)
+        isnum($i) ? header[i] = "col" i : header[i] = $i
+}
+
 
-{
+NF > 0 {
+    (NF > nf_max) ? nf_max = NF : nf_max = nf_max
     for (i=1; i<=NF; i++)
         sum[i] += $i
-    if (NF != nf_max)
-        print "line " NR " has " NF " entries, not " nf_max
 }
 
+
 END {
     for (i=1; i<=nf_max; i++)
         printf(OFMT "%s", sum[i], i < nf_max ? OFS : ORS)
 }
+