linux shell 脚本命令操作案例大全

案例1：变量、函数、判断、比较

test.sh

#!/bin/bash
echo ======================== this is a bash demo========================
printf "%s is %d years old  \n" zhengjinwei 23

declare count=10
declare fruit=apple

declare strNormal="we have $count ${fruit}'s "
declare strSpecial="we have $count ${fruit} "



function printStr()
{
        if [ $count -gt 1 ] ; then
                echo "$strNormal"
        else
                echo "$strSpecial"
        fi
}

printStr

echo $(uname)

#########################################
declare num=1000
function printNum()
{
        local num=10
        let num+=10
        echo $num
}

echo "the global num is : $num "

echo -e  "call printNum Function :" 
printNum




o "==================this is if else fi ....test demo====================="
if [ -f "test.sh" ] ; then
        echo "named test.sh is a file.."
else
        echo "named test.sh is not a file.."
fi

function checkVariableHaveNum()
{
        if [ -n "$1" ] ; then
                echo "this variable have value"
        else
                echo "this variable have not value"
        fi
}

declare g_num=10
checkVariableHaveNum $g_num

function checkVariableEqual()
{
        if [ "$1" -eq "$2" ] ; then
                printf "%d == %d " $1 $2
        elif [ "$1" -ne "$2" ] ; then
                printf "%d != %d " $1 $2
        elif [ "$1" -ge "$2" ] ; then
                printf "%d >= %d " $1 $2
        elif [  "$1" -gt "$2" ] ; then
                printf "%d > %d" $1 $2
        elif [ "$1" -lt "$2" ] ; then
                printf "%d < %d" $1 $2
        else 
                printf "%d <= %d" $1 $2
        fi
}

checkVariableEqual 2 4
checkVariableEqual 4 2
checkVariableEqual 2 2
           

案例2：字符串操作（取子串）

echo "-------------------------------------"
########this is string opt################################
#get string's length
declare strName="zhengjinwei"
declare strNameLength=${#strName}
printf "the length of %s is %d \n" $strName $strNameLength


function getChildString()
{
        local StrResourse=$1
        local nParamCount=$2
        local nStartPos=$3
        local nEndPos=$4

        if [[ $nParamCount -lt 3 ]] ; then
                echo "param less than 3 is err"
        elif [[ $nParamCount -gt 4 ]] ; then
                echo "param more than 4 is err"
        else

                if [[ $nParamCount -eq  3 ]] ; then
                        let nEndPos=${#StrResourse}
                else
                        let nEndPos=$4
                fi
        fi

        local strResult=${StrResourse:$nStartPos:$nEndPos}


        printf "the child string in %s from position %d to %d is %s: \n\n\n" $StrResourse $nStartPos $nEndPos $strResult

}

getChildString "zhengjinwei" 4 2 6

getChildString "zhengjinwei" 3 2
           

案例3：迭代、数组

###########################################################
<span style="font-size:24px;"># this is array test demo
declare array_int=(1 2 3 4 5 6 7)

printf "the int value in array_int which index is %d is %d\n\n" 0 ${array_int["0"]}

echo "=============for loop=============================="
declare array_int_len=${#array_int[*]}
for (( i=0 ;i<"$array_int_len";i++ ))
do
        echo -e ${array_int[$i]}
done

echo ""
echo "============for iterator loop================================"

for value in ${array_int[@]}
do
        echo -e $value
done
          
         
echo ""   
echo "==========while loop=================================="
        
declare i=0
while (( $i<$array_int_len ))  
do    
        echo -e ${array_int[$i]}
        let i=i+1
done
    
########################################################</span>
           

案例4：时间操作

function getNowtime()
{
        local _date=$(date +%Y-%m-%d:%H-%M-%S:%A)
        echo $_date
}

function getCostTime()
{
        local _start=$(date +%S)
        sleep 2
        local _end=$(date +%S)
        local _cost=$(( _end - _start ))
        echo $_cost
}

function getDiffTimeBetweenInSeconds()
{
        local _start=$(date +%s -d '2010-09-01 17:00:00')
        local _end=$(date +%s -d '2011-09-01 18:40:40')
        tep=$(($_end-$_start))
        tep2=$(( 3600*24 ))
        result=$(( $tep/$tep2 ))

        extra=$[ $tep%$tep2 ]

        declare _hours=0
        declare _seconds=0
        if [ $extra -ge 3600 ] ; then
                _hours=$(( $extra/3600 ))
                _seconds=$(( $extra%3600))
        else
                _hours=0
                _seconds=$extra
        fi

        printf "%d days ---%d hours ----%d seconds \n\n" $result $_hours $_seconds
}
getNowtime
getCostTime
getDiffTimeBetweenInSeconds