shell脚本应用小程序

1...100的求和

非递归：  #!/bin/bash read num count=1 sum=0 val="" ret="" while [ $count -le $num ] do    if [ $count -eq $num ];then        val=$count    elseval=${count}'+'    fi    let sum+=count    let count++    ret=${ret}${val} done echo ${ret}'='$sum 递归： #!/bin/bash read num function add(){     local val=$1     local count=0     local sum=0     local num=$val     if [ $val -eq 1 ];then         echo 1         return     fi     arr=$count1+$val     let val--     let count=$( add $val )     let sum=$count+$num     echo $sum }  ret=$(add $num)  echo $ret

结果：

[fbl@www test6_19]$ ./add.sh

100

1+2+3+4+5+6+7+8+9+10+11+12+13+14+15+16+17+18+19+20+21+22+23+24+25+26+27+28+29+30+31+32+33+34+35+36+37+38+39+40+41+42+43+44+45+46+47+48+49+50+51+52+53+54+55+56+57+58+59+60+61+62+63+64+65+66+67+68+69+70+71+72+73+74+75+76+77+78+79+80+81+82+83+84+85+86+87+88+89+90+91+92+93+94+95+96+97+98+99+100=5050

求一个文件中数的最大最小值

#!/bin/bash read namemax=0min=0count=0while read linedo    if [ $count -eq 1 ];then        min=$line    fi    (( count++ ))    if [ $max -lt $line ];then        max=$line    fi    if [ $min -gt $line ];then        min=$line    fi    done <$nameecho "max: "$max "min: "$min

斐波那契数列求和

非递归#!/bin/bashread numfib_val[0]=1fib_val[1]=1count=0function fib(){   local val=$1   while [ $count -lt $val ]   do       let fib_val[${count}+2]=${fib_val[${count}+1]}+${fib_val[$count]}       let count++   done}fib $numecho ${fib_val[$count]}递归：#!/bin/bashread numfunction fib(){   local val=$1   local num1=0   local num2=0   if [ $val -eq 0 -o $val -eq 1 ];then       echo 1       return   fi   let val--   num1=$( fib $val )   let val--   num2=$( fib $val )   let sum=$num1+$num2   echo $sum}

结果：

[fbl@www test6_19]$ ./fib.sh

1

1

[fbl@www test6_19]$ ./fib.sh

2

2

[fbl@www test6_19]$ ./fib.sh

11

144

字符串截取的应用

#!/bin/bashread namestr1=""str2=""str3=""str=""while read linedo    str1=$(echo $line|cut -c 1-3)    str2=$(echo $line|cut -c 4-6 |tr '[a-z]' '[A-Z]')    str3=$(echo $line|cut -c 7-9)    str="${str3}""${str2}""${str1}"    echo $str done <$name >file_bak

结果：

[fbl@www test6_19]$ cat file1

123abc789

456def789

364rgy532

278bsy682

[fbl@www test6_19]$ vim string.sh

[fbl@www test6_19]$ ./string.sh

file1

[fbl@www test6_19]$ cat file_bak

789ABC123

789DEF456

532RGY364

682BSY278