合格linux運維人員必會的30道shell編程實踐題及講解-11

企業實踐題11：

開發shell腳本分別實現以腳本傳參以及read讀入的方式比較2個整數大小。以屏幕輸出的方式提醒用戶比較結果。

注意：一共是開發2個腳本。當用腳本傳參以及read讀入的方式須要對變量是否爲數字、而且傳參個數作判斷。 

個人腳本=========================

#read讀入方式
#!/bin/bash
read -p "pls input num1: " num1
read -p "pls input num2: " num2
[ -z $num1 -a -z $num2 ] && {
    echo "USAGE: pls input two num {num1 num2}"
    exit 1
}

[ "`echo "$num1"|sed -r ' s#[^0-9]##g'`" = "$num1" ] || {
    echo "first arg must be int."
    exit 2
}
[ "`echo "$num2"|sed -r ' s#[^0-9]##g'`" = "$num2" ] || {
    echo "second arg must be int."
    exit 3
}

[ $num1 -lt $num2 ] && {
    echo "$num1 < $num2"
}
[ $num1 -gt $num2 ] && {
    echo "$num1 > $num2"
}
[ $num1 -eq $num2 ] && {
    echo "$num1 = $num2"
}

#腳本傳參方式
#!/bin/bash

[ $# -ne 2 ]&&{
  echo "USAGE: num1 num2"
  exit 1
}

[ "`echo "$1"|sed -r ' s#[^0-9]##g'`" = "$1" ]||{
  echo "first arg must be int."
  exit 2
}

[ "`echo "$2"|sed -r ' s#[^0-9]##g'`" = "$2" ]||{
  echo "second arg must be int."
  exit 2
}

[ $1 -lt $2 ]&&{
  echo "$1<$2"
  exit 0
}

[ $1 -eq $2 ]&&{
  echo "$1=$2"
  exit 0
}

[ $1 -gt $2 ]&&{
  echo "$1>$2"
  exit 0
}