#!/bin/bashread -p "enter a number: " number  #提示用戶輸入數(shù)字if [ -z $number ];then             #判斷用戶是否輸入，如果未輸入則打印error  echo "Error"  exitelse  jieguo=`echo "$number*1" | bc `  #把用戶的輸入值和1相乘，交給bc做運算  if [ $jieguo -eq 0 ];then          #判斷計算結果是否為0，為0則說明number非數(shù)字(字符串和0相乘結果為0)   echo "not a number"   exit  fifi

read -p "input a word :" wordif [ ! -n "$word" ] ;then  echo "you have not input a word!"else  echo "the word you input is $word"fi

#!/bin/bashif [ ! -n "$1" ] ;then  echo "you have not input a word!"else  echo "the word you input is $1"fi

#!/bin/shpara1=if [ ! $para1 ]; then echo "IS NULL"else echo "NOT NULL"fi

#!/bin/shdmin=if test -z "$dmin"then echo "dmin is not set!"else  echo "dmin is set !"fi

#!/bin/sh dmin=if [ "$dmin" = "" ]then echo "dmin is not set!"else  echo "dmin is set !"fi

#! /bin/bashecho "Input Param Is [$1]"if [ ! -n "$1" ] ;then echo "you have not input a null word!" ./app1;./app12;./app123elif [ $1 -eq 2 ];then ./app12;./app123elif [ $1 -eq 90 ];then echo "yy";fi