1 files changed, 6 insertions, 4 deletions
diff --git a/sum2.awk b/sum2.awk
index 0b2aad3..1df83ae 100644
--- a/sum2.awk
+++ b/sum2.awk
@@ -1,16 +1,18 @@
+#!/usr/bin/awk -f
+
 ### sum2.awk, print column sums
 # check that each line has the same number of fields as line one
 
-NR==1 { nfld = NF }
+NR==1 { nf_max = NF }
 
 {
     for (i=1; i<=NF; i++)
         sum[i] += $i
-    if (NF != nfld)
-        print "line " NR " has " NF " entries, not " nfld
+    if (NF != nf_max)
+        print "line " NR " has " NF " entries, not " nf_max
 }
 
 END {
     for (i=1; i<=NF; i++)
-        printf("%g%s", sum[i], i < nfld ? "  " : "\n")
+        printf("%g%s", sum[i], i < nf_max ? "  " : "\n")
 }