From 7adef2006aaff89db93c87fd1470a688fb1d4907 Mon Sep 17 00:00:00 2001
From: Tom Ryder <tom@sanctum.geek.nz>
Date: Sat, 1 Jul 2017 21:49:27 +1200
Subject: Reimplement rndl(1df) in Awk

Removes the need for the temporary file. Also refactor pks(6df) to
accommodate it.
---
 .gitignore        |  2 --
 Makefile          |  3 ---
 bin/rndl.awk      | 29 +++++++++++++++++++++++++++++
 bin/rndl.mi5      | 38 --------------------------------------
 games/pks.awk     | 10 +++++-----
 man/man1/rndl.1df |  2 +-
 6 files changed, 35 insertions(+), 49 deletions(-)
 create mode 100644 bin/rndl.awk
 delete mode 100644 bin/rndl.mi5

diff --git a/.gitignore b/.gitignore
index ce1910c3..7e2ae706 100644
--- a/.gitignore
+++ b/.gitignore
@@ -95,8 +95,6 @@ bin/rnda
 bin/rndf
 bin/rndi
 bin/rndl
-bin/rndl.sh
-bin/rndl.m4
 bin/rnds
 bin/sd2u
 bin/sec
diff --git a/Makefile b/Makefile
index 28a58805..a5af63a9 100644
--- a/Makefile
+++ b/Makefile
@@ -205,7 +205,6 @@ BINS_M4 = bin/chn.m4 \
 	bin/edda.m4 \
 	bin/oii.m4 \
 	bin/pst.m4 \
-	bin/rndl.m4 \
 	bin/swr.m4 \
 	bin/tlcs.m4 \
 	bin/try.m4 \
@@ -215,7 +214,6 @@ BINS_SH = bin/chn.sh \
 	bin/edda.sh \
 	bin/oii.sh \
 	bin/pst.sh \
-	bin/rndl.sh \
 	bin/swr.sh \
 	bin/tlcs.sh \
 	bin/try.sh \
@@ -282,7 +280,6 @@ bin/chn.sh: bin/chn.m4 include/mktd.m4
 bin/edda.sh: bin/edda.m4 include/mktd.m4
 bin/oii.sh: bin/oii.m4 include/mktd.m4
 bin/pst.sh: bin/pst.m4 include/mktd.m4
-bin/rndl.sh: bin/rndl.m4 include/mktd.m4
 bin/swr.sh: bin/swr.m4 include/mktd.m4
 bin/tlcs.sh: bin/tlcs.m4 include/mktd.m4
 bin/try.sh: bin/try.m4 include/mktd.m4
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 = $0 }
+
+# Check and print
+END {
+
+    # Check that we processed at least one line
+    if (!NR) {
+        printf "%s: No lines found on input\n", self | "cat >&2"
+        exit(1)
+    }
+
+    # Print the line
+    print ln
+}
diff --git a/bin/rndl.mi5 b/bin/rndl.mi5
deleted file mode 100644
index f99ccbea..00000000
--- a/bin/rndl.mi5
+++ /dev/null
@@ -1,38 +0,0 @@
-# Print a random line from input
-self=rndl
-
-# If there are no arguments, we're checking stdin; this is more complicated
-# than checking file arguments because we have to count the lines in order to
-# correctly choose a random one, and two passes means we require a temporary
-# file if we don't want to read all of the input into memory (!)
-if [ "$#" -eq 0 ] ; then
-
-<%
-include(`include/mktd.m4')
-%>
-
-    # We'll operate on stdin in the temp directory; write the script's stdin to
-    # it with cat(1)
-    set -- "$td"/stdin
-    cat >"$td"/stdin
-fi
-
-# Count the number of lines in the input
-lc=$(sed -- '$=;d' "$@") || exit
-
-# If there were none, bail
-case $lc in
-    ''|0)
-        printf >&2 'rndl: No lines found on input\n'
-        exit 2
-        ;;
-esac
-
-# Try to get a random seed from rnds(1df) for rndi(1df)
-seed=$(rnds)
-
-# Get a random line number from rndi(1df)
-ri=$(rndi 1 "$lc" "$seed") || exit
-
-# Print the line using sed(1)
-sed -- "$ri"'!d' "$@"
diff --git a/games/pks.awk b/games/pks.awk
index c490e8dc..c7ff320d 100644
--- a/games/pks.awk
+++ b/games/pks.awk
@@ -13,12 +13,13 @@ BEGIN {
     }
 
     # Seed the random number generator
-    srand()
+    "rnds 2>/dev/null" | getline seed
+    srand(seed)
 }
 
 # Iterate over the lines, randomly assigning the first field of each one with a
 # decreasing probability; this method
-rand() * NR < 1 { wr = $1 }
+$1 ~ /[[:alpha:]]/ && rand() * ++n < 1 { wr = $1 }
 
 # Ha, ha, ha! Incompetent!
 END {
@@ -27,11 +28,10 @@ END {
     if (!NR)
         exit 1
 
-    # Strip trailing possessives
-    sub(/'s*$/, "", wr)
+    # Strip trailing possessives and punctuation
+    sub(/[^[:alpha:]]+s*$/, "", wr)
 
     # Two or three "has"? Important decisions here folks
-    srand()
     hr = int(rand()*2+1)
     for (ha = "Ha"; hi < hr; hi++)
         ha = ha ", ha"
diff --git a/man/man1/rndl.1df b/man/man1/rndl.1df
index ec44564a..0e952724 100644
--- a/man/man1/rndl.1df
+++ b/man/man1/rndl.1df
@@ -13,7 +13,7 @@ command |
 .B rndl
 .SH DESCRIPTION
 .B rndl
-prints a random line from its input, using rndi(1df) to choose it. This is
+prints a random line from its input, using rnds(1df) as a seed. This is
 probably not a high-quality source, but should differ within seconds and
 between runs on most systems.
 .SH SEE ALSO
-- 
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