实例1
写一个脚本：如果某路径不存在，则将其创建为目录；否则显示其存在，并显示内容类型；（不要怀疑，就是这么简单）
方法1
[root@localhost 20150921]# file=/tmp/test/ddr [root@localhost 20150921]# ! [ -e $file ] && mkdir -p $file || echo $file exists. && echo "file type is `file $file`" file type is /tmp/test/ddr: directory [root@localhost 20150921]# ! [ -e $file ] && mkdir -p $file || echo $file exists. && echo "file type is `file $file`" /tmp/test/ddr exists. file type is /tmp/test/ddr: directory [root@localhost 20150921]#
方法2
#!/bin/bash # #file=$1 #! [ -e $file ] && mkdir -p $file || echo $file exists. && echo "file type is `file $file`" file=$1 if ! [ -e $file ]; then mkdir -p $file echo "create file $file" else echo "$file exists." echo "file type is `file $file`" fi
执行结果：
实例2
写一个脚本，完成如下功能；判断给定的两个数值，孰大孰小；给定数值的方法：脚本参数，命令交互；（使用read，依然如此简单）
方法1
[root@localhost 20150921]# read -p "Plz enter two integer:" num1 num2 Plz enter two integer:5 [root@localhost 20150921]# read -p "Plz enter two integer:" num1 num2 Plz enter two integer:3 5 [root@localhost 20150921]# [ $num1 -gt $num2 ] && echo "$num1 -gt $num2: num1 is greater than b" || echo "$num1 -gt $num2: num1 is not greater than b" 3 -gt 5: num1 is not greater than b [root@localhost 20150921]#
方法2
#!/bin/bash # read -p "Plz enter two integer:" num1 num2 if [ $num1 -gt $num2 ]; then echo "$num1 -gt $num2: num1 is greater than b" else echo "$num1 -gt $num2: num1 is not greater than b" fi
执行结果：
7、求100以内所有奇数之和（至少用3种方法。是的这是我们的作业^_^）
方法1
#1/bin/bash declare -i sum=0 for i in $(seq 1 2 100);do sum=$[$sum+i] done echo $sum
方法2
#!/bin/bash
#
declare -i sum=0
for i in {1..100};do
if [ $[$i%2] -eq 1 ];then
sum=$[$sum+$i]
fi
done
echo $sum方法3
#!/bin/bash # declare -i sum=0 declare -i i=0 while [ $i -le 100 ]; do if [ $[$i%2] -eq 1 ];then let sum+=$i fi let i++ done echo "Sum:$sum."
运行结果：
实例3
写一个脚本实现如下功能：
(1) 传递两个文本文件路径给脚本；
(2) 显示两个文件中空白行数较多的文件及其空白行的个数；
(3) 显示两个文件中总行数较多的文件及其总行数；
#!/bin/bash
#
for i in $1 $2;do
echo $i
awk '/^[ ]/ {++S[$NF]} END{for(a in S) print a, S[a]}' $i
awk 'BEGIN{c=0}/^[ ]/{c++}END{printf "space=%d\ncount=%d\n",c,NR}' $i
done执行结果：
实例4
(1) 提示用户输入一个字符串；
(2) 判断：
如果输入的是quit，则退出脚本；
否则，则显示其输入的字符串内容；
#!/bin/bash # echo "enter a character:" while read char do if [ $char = 'quit' ]; then break; else echo $char echo "enter a character:" fi done
执行结果：
实例5
写一个脚本，打印2^n表；n等于一个用户输入的值；（不好意思，我调皮了）
#!/bin/bash
#
declare -i sum=2
read -p "Plz enter one integer: " num1
for ((j=1;j<=$num1;j++));do
echo -n -e "${sum}^$j=$[$sum**$j]\n"
done执行结果：
11、写一个脚本，写这么几个函数：函数1、实现给定的两个数值的之和；函数2、取给定两个数值的最大公约数；函数3、取给定两个数值的最小公倍数；关于函数的选定、两个数值的大小都将通过交互式输入来提供。
#!/bin/bash
#
sum(){
# val=$[$num1+$num2]
val=`expr $num1 + $num2`
echo "Total value : $val"
}
gcd(){
if [ $num1 -eq $num2 ]; then
echo "max is：${num1},mini is：${num1}."
exit
fi
if [ $num1 -gt $num2 ]; then
GREAT=$num1
SMALL=$num2
else
GREAT=$num2
SMALL=$num1
fi
declare -i GCD_RESULT=1
declare -i greattmp=1
declare -i smalltmp=1
declare -i i=1
while [ $i -le $SMALL ]; do
greattmp=`expr $GREAT % $i`
smalltmp=`expr $SMALL % $i`
[ ${greattmp} -eq 0 ] && [ ${smalltmp} -eq 0 ] && GCD_RESULT=${i}
i=`expr ${i} + 1`
done
#LCM_RESULT=`expr $SMALL / $GCD_RESULT`
#LCM_RESULT=`expr $LCM_RESULT \* $GREAT`
echo "max is:${GCD_RESULT}"
}
lcm(){
if [ $num1 -eq $num2 ]; then
echo "max is：${num1},mini is：${num1}."
exit
fi
if [ $num1 -gt $num2 ]; then
GREAT=$num1
SMALL=$num2
else
GREAT=$num2
SMALL=$num1
fi
declare -i LCM_RESULT=1
declare -i greattmp=1
declare -i smalltmp=1
declare -i GCD_RESULT=1
declare -i i=1
while [ $i -le $SMALL ]; do
greattmp=`expr $GREAT % $i`
smalltmp=`expr $SMALL % $i`
[ ${greattmp} -eq 0 ] && [ ${smalltmp} -eq 0 ] && GCD_RESULT=${i}
i=`expr ${i} + 1`
done
LCM_RESULT=`expr $SMALL / $GCD_RESULT`
LCM_RESULT=`expr $LCM_RESULT \* $GREAT`
echo "mini is：${LCM_RESULT}."
}
prog=$(basename $0)
read -p "Plz enter two integer: " num1 num2
read -p "Plz enter sum | gcd | lcm : " num
case $num in
sum)
sum
;;
gcd)
gcd
;;
lcm)
lcm
;;
*)
echo "Usage:$prog sum|gcd|lcm"
exit 1
esac执行结果：
