1 files changed, 31 insertions, 0 deletions
diff --git a/sum3.awk b/sum3.awk
new file mode 100644
index 0000000..b4100a7
--- /dev/null
+++ b/sum3.awk
@@ -0,0 +1,31 @@
+### sum3.awk, print sums of numeric columns
+# input:    rows of integers and strings
+# output:   sums of numeric columns
+#   assumes every line has same layout
+
+NR==1 {
+    nfld = NF
+    for (i=1; i<=NF; i++)
+        numcol[i] = isnum($i)
+}
+
+{
+    for (i=1; i<=NF; i++)
+        if (numcol[i])
+            sum[i] += $i
+}
+
+END {
+    for (i=1; i<=nfld; i++) {
+        if (numcol[i])
+            printf("%g", sum[i])
+        else
+            printf("--")
+        printf(i < nfld ? "  " : "\n")
+    }
+}
+
+function isnum(n) {
+    return n ~ /^[+-]?[0-9]+$/
+}
+