From 4c16e777b2994a0aa962a9e7bc1bda7e4f8676fd Mon Sep 17 00:00:00 2001
From: Jakob Kaivo <jkk@ung.org>
Date: Fri, 26 Jul 2019 21:10:54 -0400
Subject: implement shuf

---
 .gitignore |  1 +
 Makefile   |  2 +-
 shuf       |  0
 shuf.sh    | 18 ++++++++++++++++++
 4 files changed, 20 insertions(+), 1 deletion(-)
 delete mode 100644 shuf
 create mode 100644 shuf.sh

diff --git a/.gitignore b/.gitignore
index 0c0912d..0ee44ae 100644
--- a/.gitignore
+++ b/.gitignore
@@ -9,6 +9,7 @@ nproc
 pinky
 printenv
 readlink
+shuf
 seq
 stdbuf
 tac
diff --git a/Makefile b/Makefile
index 66a0ca2..4a8a295 100644
--- a/Makefile
+++ b/Makefile
@@ -1,7 +1,7 @@
 .POSIX:
 
 PROGRAMS=arch base64 factor hostid mktemp nproc pinky printenv readlink \
-	seq stdbuf sync tac uptime users vdir yes
+	seq shuf stdbuf sync tac uptime users vdir yes
 
 all: $(PROGRAMS)
 
diff --git a/shuf b/shuf
deleted file mode 100644
index e69de29..0000000
diff --git a/shuf.sh b/shuf.sh
new file mode 100644
index 0000000..d0fe4fb
--- /dev/null
+++ b/shuf.sh
@@ -0,0 +1,18 @@
+exec awk "$(tail -n +2 $0)" "$@"
+
+{
+	lines[NR] = $0;
+	printed[NR] = 0;
+}
+
+END {
+	nprinted = 0;
+	while (nprinted < NR) {
+		line = int(rand() * NR);
+		if (!printed[line]) {
+			print lines[line];
+			printed[line] = 1;
+			nprinted++;
+		}
+	}
+}
-- 
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