shell命令的相关事例操作

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>
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
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>