randomness checker

diff --git a/randomness.sh b/randomness.sh
new file mode 100755 (executable)
index 0000000..47022f5
--- /dev/null
+++ b/randomness.sh
@@ -0,0 +1,52 @@
+#!/bin/bash
+# Visualize how random the $RANDOM function is
+# while demonstrating some neat array functions and things
+
+# Check for sane parameter
+if [[ "${1}" -lt 50 ]]; then
+    echo "Please input integer higher than 50"
+    exit 1
+fi
+
+# Declare arrays
+declare -A Count=()
+declare -A Graph=()
+
+# Loop n times
+for ((n=0;n<${1};n++)); do
+    # Assign random number, use modulo to reduce to desired range, add 1 to get rid of 0
+    Rand=$(( ( RANDOM % 8 )  + 1 ))
+    # Our Count array needs to be increased
+    (( Count[${Rand}]++ ))
+    # And append a character to our graph
+    Graph[$Rand]+=█
+done
+
+# Find extremes
+Max=${Count[1]}
+for n in "${Count[@]}"; do
+    (( n > Max )) && Max=${n}
+done
+
+Min=${Count[1]}
+for n in "${Count[@]}"; do
+    (( n < Min )) && Min=${n}
+done
+
+# Find mean
+Mean=$(bc <<< "scale=2;${1}/${#Count[@]}")
+
+# Unset Graph array if we can't get it to fit on screen
+MaxWidth=$(tput cols)
+(( MaxWidth -= 10 ))
+
+if [[ "${Max}" -gt "${MaxWidth}" ]]; then
+    unset Graph
+fi
+
+# Loop through the Count array, note the # which returns the size of the array for us
+for ((n=1;n<=${#Count[@]};n++)); do
+    # printf to get some better formatting (space padding)
+    printf "%-3s %-5s %s\n" ${n} ${Count[$n]} ${Graph[$n]}
+done
+echo -e "\nMin: ${Min}, Max: ${Max}, Mean: ${Mean}"
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