SHELL 示例

處理命令行參數

測試： sh test.sh -b qiao -a -c  -- asdf sd  w w

#!/bin/bash

while getopts :ab:c opt
do
    case "$opt" in 
    a) echo fund -a;;
    b) echo fund -b with option $OPTARG;;
    c) echo fund -c ;;
    *) echo unknown arg $opt;;
    esac
done

#echo $* $OPTIND

shift $[ $OPTIND - 1 ]

count=1
for i in "$@"
do
    echo para $count is $i
    count=$[ $count+1 ]
done

讀取命令

#!/bin/bash                                                                                                                                                                  
read -p "Enter your name please:"  first last
echo Welcom $last.$first
read -p "And your favourate?:"
echo Your favourate is : $REPLY

設置超時時間：

#!/bin/bash
# timing read

if read -t 5 -p "請輸入姓名：" name 
then
    echo Welcom $name!                                                                                                                                                                                                                       
else
    echo "Sorry, timeout!!"
fi

~
~

讀取文件：

#!/bin/bash
#讀取文件測試
cat /etc/passwd | while read line                                                                                                                                                                                                            
do
    echo Line: $line
    IFS_OLD=$IFS    
    IFS=:
    for value in $line
    do  
        echo "  $value"
    done
    IFS=$IFS_OLD
done
~

信號

禁止中斷 （使用trap命令）

#!/bin/bash
trap "echo '您不能中斷執行'" SIGINT SIGTERM
echo "測試開始"
count=1
while [ $count -lt 5 ]
do 
    echo "Loop #$count"
    sleep 3
    count=$[$count+1]
done

函數

#!/bin/bash
echo "Now Program [$(basename $0)] Begin. PID: $$ TIME:$(date)"

function addem {
    if [ $# -le 0 ] || [ $# -gt 2 ]
    then
        echo -1
    elif [ $# -eq 1 ]
    then
        echo $[ $1 + $1 ]
    else
        echo $[ $1 + $2 ]
    fi


}

r1=$(addem 1 3)
r2=$(addem 1)

r3=$(addem)

echo r1:$r1 r2:$r2 r3:$r3

函數裏的全局變量： 默認都是全局的

#!/bin/bash
echo "Now Program [$(basename $0)] Begin. PID: $$ TIME:$(date)"

function dbl {
    value=$[ $value*2]
}
read -p"Please enter a value:" value
dbl
echo the new value is $value

數組傳參

#!/bin/bash
echo "Now Program [$(basename $0)] Begin. PID: $$ TIME:$(date)"

function testarray {
    local newArray=(`echo "$@"`)
    echo the new array in func is : ${newArray[*]}
}
myarray=(one two three)
echo the original array is : ${myarray[*]}
testarray ${myarray[*]}

返回數組

#!/bin/bash
echo "Now Program [$(basename $0)] Begin. PID: $$ TIME:$(date)"

function testarray {
    local arr=(2 3 4 5)
    echo ${arr[*]}
}
myarray=$(testarray)
echo the array is : ${myarray[*]}

遞歸（斐波那契數列）

#!/bin/bash
function factorial {
    if [ $1 -eq 1 ] 
    then
        echo $1
    else
        local tmp=$(factorial $[ $1-1 ])
        echo $[ $tmp * $1 ]
    fi
}
read -p"Please enter:" val
result=$(factorial $val)
echo The factorial of $val is $result

sed 與 gawk

統計 $PATH 中各個目錄中文件的個數

#!/bin/bash

allPath=$(echo $PATH | sed 's/:/ /g')
for dir in $allPath
do
    check=$(ls $dir)
    count=0
    for file in $check
    do
        count=$[ $count+1 ]
    done
    echo $dir - $count
done

給數字添加“ ，” ，其中的正則表達式爲：

#!/bin/bash
factorial=1
counter=1
read -p"Enter a number:" number
#number=$1

while [ $counter -lt $number ]
do
    factorial=$[ $factorial * $counter]    
    counter=$[ $counter+1 ]

done
echo Original data: $factorial
result=$(echo $factorial | sed '{
        :start
        s/\(.*[0-9]\)\([0-9]\{3\}\)/\1,\2/
        t start
        }')
echo $result

每行前添加行號

 sed '=' test.txt  sed 'N;s/\n/ /'

刪除多餘空白行 （連續空白多餘一行）

sed '/./,/^$/!d' test.txt

實用工具

列出家目錄下，按大小排序的前十名的文件，並輸出總大小

du  --max-depth=1 ~ | sort -nr | sed "="  | sed "N; s/\n/ /g" | sed '{11,$D}' |gawk 'BEGIN{total=0}{total+=$2;print $1":",$2,$3;}END{print "TOTAL:"total}'

du  --max-depth=1 ~ | sort -nr | sed "="  | sed "N; s/\n/ /g" | sed '{11,$D}' |gawk 'BEGIN{total=0}{total+=$2;print $1":",$2,$3;}END{print "TOTAL:"total}'

Delete_User.sh

shell中的${}，##和%%的使用

http://blog.csdn.net/shmilyringpull/article/details/7631106