生成随机数

shell/random.sh

@@ -0,0 +1,121 @@
+#!/bin/bash
+
+#-----------------------------------------------------------
+# Usage: 生成随机数
+#
+#-----------------------------------------------------------
+
+
+function TimestampRand()
+{
+    range=$1
+    timestamp=`date +%s%N`
+    let res=$timestamp%$range
+    echo $res
+}
+
+function RandomRand()
+{
+    range=$1
+    let res=$RANDOM%$range
+    echo $res
+}
+
+function UrandomRand()
+{
+    range=$1
+    rand=`head -200 /dev/urandom | cksum | cut -f1 -d" "`
+    let res=$rand%$range
+    echo $res
+}
+
+function UuidRand()
+{
+    range=$1
+    rand=`cat /proc/sys/kernel/random/uuid| cksum | cut -f1 -d" "`
+    let res=$rand%$range
+    echo $res
+}
+
+
+function exp()
+{
+    echo "基于时间戳: `TimestampRand 10`"
+    echo "基于\$RANDOM: `RandomRand 10`"
+    echo "基于urandom: `UrandomRand 10`"
+    echo "基于uuid: `UuidRand 10`"
+    
+    str=""
+    for i in `seq 1 6`;do
+        str="$str`RandomRand 9`"
+    done
+    
+    echo $str
+    echo "字符翻转:"
+    echo $str | rev
+    
+    echo $str | awk '{for(i=1;i<=length;i++){line=substr($0,i,1)line}}END{print line}'
+}
+
+$@ 
+[root@node130 tmp]# cat b.sh 
+#!/bin/bash
+
+#-----------------------------------------------------------
+# Usage: 生成随机数
+#
+#-----------------------------------------------------------
+
+
+function TimestampRand()
+{
+    range=$1
+    timestamp=`date +%s%N`
+    let res=$timestamp%$range
+    echo $res
+}
+
+function RandomRand()
+{
+    range=$1
+    let res=$RANDOM%$range
+    echo $res
+}
+
+function UrandomRand()
+{
+    range=$1
+    rand=`head -200 /dev/urandom | cksum | cut -f1 -d" "`
+    let res=$rand%$range
+    echo $res
+}
+
+function UuidRand()
+{
+    range=$1
+    rand=`cat /proc/sys/kernel/random/uuid| cksum | cut -f1 -d" "`
+    let res=$rand%$range
+    echo $res
+}
+
+
+function exp()
+{
+    echo "基于时间戳: `TimestampRand 10`"
+    echo "基于\$RANDOM: `RandomRand 10`"
+    echo "基于urandom: `UrandomRand 10`"
+    echo "基于uuid: `UuidRand 10`"
+    
+    str=""
+    for i in `seq 1 6`;do
+        str="$str`RandomRand 9`"
+    done
+    
+    echo $str
+    echo "字符翻转:"
+    echo $str | rev
+    
+    echo $str | awk '{for(i=1;i<=length;i++){line=substr($0,i,1)line}}END{print line}'
+}
+
+$@