Reimplement rndl(1df) in Awk

Removes the need for the temporary file. Also refactor pks(6df) to
accommodate it.

1 files changed, 29 insertions, 0 deletions

diff --git a/bin/rndl.awk b/bin/rndl.awk
new file mode 100644
index 00000000..8359af90
--- /dev/null
+++ b/bin/rndl.awk
@@ -0,0 +1,29 @@
+# Print a random line from input
+
+# Process arguments
+BEGIN {
+
+    # Name self
+    self = "rndl"
+
+    # Seed the random number generator
+    "rnds 2>/dev/null" | getline seed
+    srand(seed)
+}
+
+# Iterate over the lines, randomly assigning the first field of each one with a
+# decreasing probability
+rand() * NR < 1 { ln = $0 }
+
+# Check and print
+END {
+
+    # Check that we processed at least one line
+    if (!NR) {
+        printf "%s: No lines found on input\n", self | "cat >&2"
+        exit(1)
+    }
+
+    # Print the line
+    print ln
+}