Add 1994/weisberg/try.sh and primes.sh

The primes.sh script is like 1985/august/primes.sh but it only acts on
reversed output (if rev(1) is installed) of the weisberg because
weisberg actually prints out primes so there's no point doing it without
reversing it. One can specify the number of lines to reverse (not how
many primes to show) by passing an arg to the script. The try.sh script
uses the default (15) and also 25.

1994/weisberg/primes.sh

@@ -0,0 +1,40 @@
+#!/usr/bin/env bash
+# 
+# primes.sh - feed primes(1) IOCCC winner 1994/weisberg
+#
+
+# make sure CC is set so that when we do make CC="$CC" it isn't empty. Doing it
+# this way allows us to have the user specify a different compiler in an easy
+# way.
+if [[ -z "$CC" ]]; then
+    CC="cc"
+fi
+
+make CC="$CC" all >/dev/null || exit 1
+
+PRIMES=$(type -P primes)
+
+COUNT=15
+if [[ "$#" -ge 1 ]]; then
+    COUNT="$1"
+    if ! [[ $COUNT =~ ^[0-9]+$ ]]; then
+	echo "not a number: $COUNT" 1>&2	
+	exit 1
+    fi
+fi
+
+REV="$(type -P rev)"
+if [[ -n "$PRIMES" && -n "$REV" ]]; then
+    read -r -n 1 -p "Press any key to find primes in ./weisberg | head -n $COUNT, reversed: "
+    echo 1>&2
+    while read -r n; do primes "$n" $((n + 1)); done < <((./weisberg | head -n "$COUNT" | "$REV" ))
+else
+    echo "primes not installed" 1>&2
+    echo 1>&2
+    echo "See the following GitHub repo:" 1>&2
+    echo 1>&2
+    echo "	https://github.com/vattam/BSDGames" 1>&2
+    echo 1>&2
+    echo "and after installing it try running this again."
+    exit 1
+fi