mirror of https://github.com/fengyuhetao/shell.git
2016-05-13
commit
847f5e7495
|
@ -0,0 +1,9 @@
|
|||
#!/bin/bash
|
||||
#退出状态码,最大为255,超过则进行模运算
|
||||
#testing the exit status
|
||||
var1=10
|
||||
var2=20
|
||||
var3=$[ $var1 + $var2]
|
||||
echo The answer is $var3
|
||||
exit 5
|
||||
|
|
@ -0,0 +1,8 @@
|
|||
#!/bin/bash
|
||||
#An example of using the expr command
|
||||
|
||||
var1=10
|
||||
var2=20
|
||||
var3=`expr $var2 / $var1`
|
||||
echo "The result is $var3"
|
||||
|
|
@ -0,0 +1,15 @@
|
|||
#!/bin/bash
|
||||
|
||||
var1=10.45
|
||||
var2=43.67
|
||||
var3=33.2
|
||||
var4=71
|
||||
|
||||
var5=`bc <<EOF
|
||||
scale=4
|
||||
a1 = $var1 * $var2
|
||||
b1 = $var3 * $var4
|
||||
a1 + b1
|
||||
EOF
|
||||
`
|
||||
echo The final answer for this mess is $var5
|
|
@ -0,0 +1,7 @@
|
|||
#!/bin/bash
|
||||
|
||||
var1=10
|
||||
var2=50
|
||||
var3=45
|
||||
var4=$[$var1 * ($var2 - $var3)]
|
||||
echo 'The final result is '$var4
|
|
@ -0,0 +1,9 @@
|
|||
#!/bin/bash
|
||||
#testing variables
|
||||
|
||||
days=10
|
||||
guest="Katie"
|
||||
echo "$guest logged in $days days age"
|
||||
guest="Katie2"
|
||||
days=5
|
||||
echo "$guest logged in $days days age"
|
|
@ -0,0 +1,5 @@
|
|||
#!/bin/bash
|
||||
#using the backtick character
|
||||
|
||||
testing=`date`
|
||||
echo "The date and time are:$testing"
|
|
@ -0,0 +1,6 @@
|
|||
#!/bin/bash
|
||||
var1=100
|
||||
var2=45
|
||||
var3=`echo "scale=4; $var1 / $var2" | bc`
|
||||
echo The answer for this is $var3
|
||||
|
|
@ -0,0 +1,12 @@
|
|||
#!/bin/bash
|
||||
#This script displays the date and who's logged on
|
||||
|
||||
#如果想在同一行显示
|
||||
#echo -n -e 'The time is:\n\n'
|
||||
echo The time is:
|
||||
date
|
||||
echo The one who has been logged is:
|
||||
who
|
||||
|
||||
|
||||
|
|
@ -0,0 +1,10 @@
|
|||
#!/bin/bash
|
||||
#display user information from system
|
||||
|
||||
echo "User info fro userId:$USER"
|
||||
echo UID:$UID
|
||||
echo HOME:$HOME
|
||||
#换行
|
||||
echo -e '\n'
|
||||
echo 'The cost of the item is \$15'
|
||||
|
|
@ -0,0 +1,5 @@
|
|||
#!/bin/bash
|
||||
#copy the /usr/bin directory listing to a log file
|
||||
|
||||
today=`date +%y%m%d`
|
||||
ls /usr/bin -al > log.$today
|
|
@ -0,0 +1,11 @@
|
|||
#!/bin/bash
|
||||
# reading data from a file
|
||||
|
||||
count=1
|
||||
cat test | while read line
|
||||
do
|
||||
echo "Line $count: $line"
|
||||
count=$[ $count + 1 ]
|
||||
done
|
||||
echo "Finished processing the file"
|
||||
|
|
@ -0,0 +1,12 @@
|
|||
#!/bin/bash
|
||||
# simple demonstration of the getopts command
|
||||
|
||||
while getopts :ab:c opt
|
||||
do
|
||||
case "$opt" in
|
||||
a) echo "Found the -a option";;
|
||||
b) echo "Found the -b option, with value $OPTARG";;
|
||||
c) echo "Found the -c option";;
|
||||
*) echo "Unknown option:$opt";;
|
||||
esac
|
||||
done
|
|
@ -0,0 +1,20 @@
|
|||
#!/bin/bash
|
||||
# processing options and parameters with getopts
|
||||
|
||||
while getopts :ab:cd opt
|
||||
do
|
||||
case "$opt" in
|
||||
a) echo "Found the -a option";;
|
||||
b) echo "Found the -b option,with value $OPTARG";;
|
||||
c) echo "Found the -c option";;
|
||||
d) echo "Found the -d option";;
|
||||
*) echo "Unknown option: $opt";;
|
||||
esac
|
||||
done
|
||||
shift $[ $OPTIND - 1 ]
|
||||
count=1
|
||||
for param in "$@"
|
||||
do
|
||||
echo "Parameter $count: $param"
|
||||
count=$[ $count + 1 ]
|
||||
done
|
|
@ -0,0 +1,25 @@
|
|||
#!/bin/bash
|
||||
#extracting command line options and values with getopt
|
||||
# getopt command is not goot at dealing with space,we can use getopts
|
||||
set -- `getopt -q ab:c "$@"`
|
||||
while [ -n "$1" ]
|
||||
do
|
||||
case "$1" in
|
||||
-a) echo "Found the -a option";;
|
||||
-b) param="$2"
|
||||
echo "Found the -b option,with parameter value $param"
|
||||
shift;;
|
||||
-c) echo "Found the -c option";;
|
||||
--) shift
|
||||
break;;
|
||||
*) echo "$1 is not an option";;
|
||||
esac
|
||||
shift
|
||||
done
|
||||
|
||||
count=1
|
||||
for param in "$@"
|
||||
do
|
||||
echo "Parameter #$count: $param"
|
||||
count=$[ $count+1 ]
|
||||
done
|
|
@ -0,0 +1,17 @@
|
|||
#!/bin/bash
|
||||
# shift n 移动变量
|
||||
|
||||
count=1
|
||||
while [ -n "$1" ]
|
||||
do
|
||||
echo "Parameter #$count = $1"
|
||||
count=$[ $count+1 ]
|
||||
shift
|
||||
done
|
||||
|
||||
echo -e "\n"
|
||||
|
||||
# demonstrating a multi-position shift
|
||||
echo "The original parameters : $*"
|
||||
shift 2
|
||||
echo "Here's the new first parameter: $1"
|
|
@ -0,0 +1,23 @@
|
|||
#!/bin/bash
|
||||
|
||||
#extracting options and parameters
|
||||
|
||||
while [ -n "$1" ]
|
||||
do
|
||||
case "$1" in
|
||||
-a) echo "Found the -a option";;
|
||||
-b) echo "Found the -b option";;
|
||||
-c) echo "Found the -c option";;
|
||||
--) shift
|
||||
break;;
|
||||
*) echo "$1 is not an option";;
|
||||
esac
|
||||
shift
|
||||
done
|
||||
|
||||
count=1
|
||||
for param in $@
|
||||
do
|
||||
echo "Parameter #$count: $param"
|
||||
count=$[ $count + 1 ]
|
||||
done
|
|
@ -0,0 +1,10 @@
|
|||
#!/bin/bash
|
||||
# getting the number of parameters
|
||||
|
||||
echo There were $# parameters supplied
|
||||
|
||||
#花括号里不能使用美元符号
|
||||
params=$#
|
||||
|
||||
echo The last parameter is $params
|
||||
echo The last parameter is ${!#}
|
|
@ -0,0 +1,25 @@
|
|||
#!/bin/bash
|
||||
|
||||
# extracting command line options and values
|
||||
|
||||
while [ -n "$1" ]
|
||||
do
|
||||
case "$1" in
|
||||
-a) echo "Found the -a option";;
|
||||
-b) param="$2"
|
||||
echo "Found the -b option, with parameter value $param"
|
||||
shift;;
|
||||
-c) echo "Found the -c option";;
|
||||
--) shift
|
||||
break;;
|
||||
*) echo "$1 is not an option";;
|
||||
esac
|
||||
shift
|
||||
done
|
||||
|
||||
count=1
|
||||
for param in "$@"
|
||||
do
|
||||
echo "Parameter #$count : $param"
|
||||
count=$[ $count + 1 ]
|
||||
done
|
|
@ -0,0 +1,13 @@
|
|||
#!/bin/bash
|
||||
# extracting command line options as parameters
|
||||
|
||||
while [ -n "$1" ]
|
||||
do
|
||||
case "$1" in
|
||||
-a) echo "Found the -a option";;
|
||||
-b) echo "Found the -b optins";;
|
||||
-c) echo "Found the -c optins";;
|
||||
*) echo "$1 is not a valid options";;
|
||||
esac
|
||||
shift
|
||||
done
|
|
@ -0,0 +1,16 @@
|
|||
#!/bin/bash
|
||||
# testing $* and $@
|
||||
|
||||
count=1
|
||||
for param in "$*"
|
||||
do
|
||||
echo "\$* Parameter #$count = $param"
|
||||
count=$[ $count+1 ]
|
||||
done
|
||||
|
||||
count=1
|
||||
for param in "$@"
|
||||
do
|
||||
echo "\$@ Paramenter #$count = $param"
|
||||
count=$[ $count+1 ]
|
||||
done
|
|
@ -0,0 +1,27 @@
|
|||
#!/bin/bash
|
||||
|
||||
# testing the reading command
|
||||
|
||||
echo -n "Enter your name:"
|
||||
read name
|
||||
echo "Hello $name, welcome to my program"
|
||||
|
||||
read -p "Please enter your age: " age
|
||||
days=$[ $age * 365 ]
|
||||
echo "That makes you over $days days old"
|
||||
|
||||
#指定多个变量,输入的每个数据值都会分配给表中的下一个变量,如果用完了,就全分配各最后一个变量
|
||||
read -p "Please enter name:" first last
|
||||
echo "Checking data for $last. $first..."
|
||||
|
||||
#如果不指定变量,read命令就会把它收到的任何数据都放到特殊环境变量REPLY中
|
||||
read -p "Enter a number:"
|
||||
factorial=1
|
||||
for (( count=1; count<=$REPLY; count++))
|
||||
do
|
||||
factorial=$[ $factorial * $count ]
|
||||
done
|
||||
echo "The factorial of $REPLY is $factorial"
|
||||
|
||||
|
||||
|
|
@ -0,0 +1,10 @@
|
|||
#!/bin/bash
|
||||
|
||||
# using one command line parameter
|
||||
|
||||
factorial=1
|
||||
for (( number = 1; number <= $1; number++))
|
||||
do
|
||||
factorial=$[ $factorial * $number ]
|
||||
done
|
||||
echo The factor of $1 is $factorial
|
|
@ -0,0 +1,8 @@
|
|||
#!/bin/bash
|
||||
|
||||
# handing lots of parameters
|
||||
|
||||
total=$[ ${10} * ${11} ]
|
||||
echo The tenth parameter is ${10}
|
||||
echo The eleventh parameter is ${11}
|
||||
echo The total is $total
|
|
@ -0,0 +1,9 @@
|
|||
#!/bin/bash
|
||||
# testing the $0 parameter
|
||||
|
||||
echo The command entered is $0
|
||||
|
||||
#当传给$0变量的真实字符串是整个脚本的路径是,程序中就会使用整个路径,而不仅仅是程序名
|
||||
|
||||
name=`basename $0`
|
||||
echo The command entered is $name
|
|
@ -0,0 +1,22 @@
|
|||
#!/bin/bash
|
||||
# timing the data entry
|
||||
|
||||
if read -t 5 -p "Please enter your name:" name
|
||||
then
|
||||
echo "Hello, $name, welcome to my script"
|
||||
else
|
||||
#起到换行的作用
|
||||
echo
|
||||
#输入计数 -n1
|
||||
read -n1 -p "Do you want to continue [Y/N]?" answer
|
||||
case $answer in
|
||||
Y | y) echo
|
||||
echo "Fine, continue on...";;
|
||||
N | n) echo
|
||||
echo "OK,goodbye";;
|
||||
*) echo
|
||||
echo "OK, wrong, goodbye"
|
||||
esac
|
||||
echo "Sorry, this is the end of the script"
|
||||
fi
|
||||
|
|
@ -0,0 +1,8 @@
|
|||
#!/bin/bash
|
||||
# hiding input data from monitor
|
||||
|
||||
read -s -p "Please enter your password: " pass
|
||||
|
||||
#添加了-s选项之后,不会自动换行,不添加-s 会自动换行
|
||||
echo
|
||||
echo "Is your password really $pass?"
|
|
@ -0,0 +1 @@
|
|||
#!/bin/bash
|
|
@ -0,0 +1 @@
|
|||
#!/bin/bash
|
|
@ -0,0 +1 @@
|
|||
#!/bin/bash
|
|
@ -0,0 +1,10 @@
|
|||
#!/bin/bash
|
||||
|
||||
#创建10个sh
|
||||
|
||||
for (( i=1; i<=4; i++))
|
||||
do
|
||||
touch $i.sh
|
||||
echo '#!/bin/bash' > $i.sh
|
||||
chmod 764 $i.sh
|
||||
done
|
|
@ -0,0 +1,2 @@
|
|||
ls: cannot access badtest: No such file or directory
|
||||
but this should go to the testerror file
|
|
@ -0,0 +1 @@
|
|||
This is the end of the script
|
|
@ -0,0 +1,6 @@
|
|||
#!/bin/bash
|
||||
# testing STDERR messages
|
||||
|
||||
echo "This is an error " >&2
|
||||
echo "This is another error"
|
||||
echo "This is also an error" >&2
|
|
@ -0,0 +1,12 @@
|
|||
#!/bin/bash
|
||||
# redirecting the inpiut
|
||||
|
||||
# 从test中读取数据,而不是从STDIN中读取数据
|
||||
exec 0< test
|
||||
count=1
|
||||
while read line
|
||||
do
|
||||
echo "Line #$count : $line "
|
||||
count=$[ $count +1 ]
|
||||
done
|
||||
|
|
@ -0,0 +1,14 @@
|
|||
#!/bin/bash
|
||||
# testing STDERR messages
|
||||
# redirecting all to a file
|
||||
|
||||
# 脚本执行期间,用exec命令告诉shell重定向某个特定文件描述符
|
||||
exec 2>test
|
||||
|
||||
ls badtest
|
||||
echo "This is test of redirecting all output"
|
||||
echo "from a script to another file"
|
||||
|
||||
exec 1>test1
|
||||
echo "This is the end of the script"
|
||||
echo "but this should go to the testerror file" >&2
|
|
@ -0,0 +1,11 @@
|
|||
#!/bin/bash
|
||||
#bash shell 仅能处理浮点数值,test命令无法处理val1变量中存储的浮点值
|
||||
|
||||
#testing floating point numbers
|
||||
|
||||
val1=`echo "scale=4; 10 / 3" | bc`
|
||||
echo "The test value is $val1"
|
||||
if [ $val1 -gt 3 ]
|
||||
then
|
||||
echo "The result is larger than 3"
|
||||
fi
|
|
@ -0,0 +1,16 @@
|
|||
#!/bin/bash
|
||||
#continuing an outer loop
|
||||
|
||||
for (( a=1; a<=5; a++))
|
||||
do
|
||||
echo "Iteration $a:"
|
||||
for (( b=1; b<3; b++ ))
|
||||
do
|
||||
if [ $a -gt 2 ] && [ $a -lt 4 ]
|
||||
then
|
||||
continue 2
|
||||
fi
|
||||
var3=$[ $a * $b ]
|
||||
echo " The result of $a * $b is $var3"
|
||||
done
|
||||
done
|
|
@ -0,0 +1,10 @@
|
|||
#!/bin/bash
|
||||
#testing the else section
|
||||
testuser=badtest
|
||||
if grep $testuser /etc/passwd
|
||||
then
|
||||
echo The files for user $testuser are:
|
||||
ls -a /home/.b*
|
||||
else
|
||||
echo "The user name $testuser does not exist on this system"
|
||||
fi
|
|
@ -0,0 +1,12 @@
|
|||
#!/bin/bash
|
||||
#testing the if statement
|
||||
if date
|
||||
then
|
||||
echo "it worked"
|
||||
fi
|
||||
echo -e '\n'
|
||||
if asd
|
||||
then
|
||||
echo "it not worked"
|
||||
fi
|
||||
echo 'We are outside the if statement'
|
|
@ -0,0 +1,12 @@
|
|||
/home/tiandi/Desktop is a directory
|
||||
/home/tiandi/Documents is a directory
|
||||
/home/tiandi/Downloads is a directory
|
||||
/home/tiandi/examples.desktop is a file
|
||||
/home/tiandi/lamp is a directory
|
||||
/home/tiandi/Music is a directory
|
||||
/home/tiandi/Pictures is a directory
|
||||
/home/tiandi/Public is a directory
|
||||
/home/tiandi/sh is a directory
|
||||
/home/tiandi/Templates is a directory
|
||||
/home/tiandi/test is a directory
|
||||
/home/tiandi/Videos is a directory
|
|
@ -0,0 +1,16 @@
|
|||
#!/bin/bash
|
||||
|
||||
# placing a for loop inside a while loop
|
||||
|
||||
var1=5
|
||||
|
||||
while [ $var1 -ge 0 ]
|
||||
do
|
||||
echo "Outer loop: $var1"
|
||||
for (( var2=1; $var2 < 3; var2++))
|
||||
do
|
||||
var3=$[ $var1*$var2]
|
||||
echo "Inner loop: $var1 * $var2 = $var3"
|
||||
done
|
||||
var1=$[ $var1 - 1 ]
|
||||
done
|
|
@ -0,0 +1,11 @@
|
|||
#!/bin/bash
|
||||
#nesting for loops
|
||||
|
||||
for (( a=1; a<=3; a++ ))
|
||||
do
|
||||
echo "Starting loop $a:"
|
||||
for (( b=1; b<=3; b++))
|
||||
do
|
||||
echo "Inside loog: $b:"
|
||||
done
|
||||
done
|
|
@ -0,0 +1,11 @@
|
|||
#!/bin/bash
|
||||
# using a variable to hold the list
|
||||
|
||||
list="Alabama Alaska Arizona"
|
||||
list=$list" Connecticut"
|
||||
|
||||
for state in $list
|
||||
do
|
||||
echo "Have you ever visited $state"
|
||||
done
|
||||
|
|
@ -0,0 +1,18 @@
|
|||
#!/bin/bash
|
||||
#reading values from a file
|
||||
|
||||
file="state"
|
||||
|
||||
#更改字段分隔符,使其只能识别换行符
|
||||
IFS=$'\n'
|
||||
|
||||
#处理长脚本是,在一个地方修改了该值,然后可能忘了修改过该值
|
||||
#IFS.OLD=$IFS
|
||||
#IFS=$'\n'
|
||||
#具体代码
|
||||
#IFS=$IFS.OLD
|
||||
|
||||
for state in `cat $file`
|
||||
do
|
||||
echo "Visit beautiful $state"
|
||||
done
|
|
@ -0,0 +1,7 @@
|
|||
#!/bin/bash
|
||||
#testing the C-style for loop
|
||||
|
||||
for (( i=1; i<=10; i++ ))
|
||||
do
|
||||
echo "The next number is $i"
|
||||
done
|
|
@ -0,0 +1,16 @@
|
|||
#!/bin/bash
|
||||
# break n,默认为1
|
||||
|
||||
for (( a=1; a<=3; a++ ))
|
||||
do
|
||||
echo "Outer loop : $a"
|
||||
for (( b=1; b < 100; b++ ))
|
||||
do
|
||||
if [ $b -gt 4 ]
|
||||
then
|
||||
break 2
|
||||
fi
|
||||
echo " Inner loop:$b"
|
||||
done
|
||||
done
|
||||
|
|
@ -0,0 +1,15 @@
|
|||
#!/bin/bash
|
||||
|
||||
#using the case command
|
||||
|
||||
case $USER in
|
||||
tiandi | barbar)
|
||||
echo "Welcome, $USER"
|
||||
echo "Pleas enjoy your visit";;
|
||||
testing)
|
||||
echo "Special testing account";;
|
||||
jessica)
|
||||
echo "Do not forget to logout when you are out";;
|
||||
*)
|
||||
echo "Sorry, you are not allowed here";;
|
||||
esac
|
|
@ -0,0 +1,12 @@
|
|||
#!/bin/bash
|
||||
|
||||
#using the continue command
|
||||
|
||||
for (( var1 = 1; var1 < 15; var1++ ))
|
||||
do
|
||||
if [ $var1 -gt 5 ] && [ $var1 -lt 10 ]
|
||||
then
|
||||
continue
|
||||
fi
|
||||
echo "Iteration number:$var1"
|
||||
done
|
|
@ -0,0 +1,19 @@
|
|||
#!/bin/bash
|
||||
|
||||
# looking for a possible value
|
||||
|
||||
if [ $USER = "tiandi" ]
|
||||
then
|
||||
echo "Welcome $USER"
|
||||
echo "Please enjoy your visit"
|
||||
elif [ $USER = testing ]
|
||||
then
|
||||
echo "Welcome $USER"
|
||||
echo "Please enjoy your visit"
|
||||
elif [ $USER = barbar ]
|
||||
then
|
||||
echo "Do not forget to logout when you're done"
|
||||
else
|
||||
echo "Sorry, you are not allowed here"
|
||||
fi
|
||||
|
|
@ -0,0 +1,15 @@
|
|||
#!/bin/bash
|
||||
var1=10
|
||||
var2=5
|
||||
if [ $var1 -gt 5 ]
|
||||
then
|
||||
echo "The test value $var1 is greater than 5"
|
||||
fi
|
||||
if [ $var1 -eq $var2 ]
|
||||
then
|
||||
echo "The values is equal"
|
||||
else
|
||||
echo "The values are different"
|
||||
fi
|
||||
|
||||
|
|
@ -0,0 +1,21 @@
|
|||
#!/bin/bash
|
||||
|
||||
#using the until command
|
||||
|
||||
var1=100
|
||||
until [ $var1 -eq 0 ]
|
||||
do
|
||||
echo $var1
|
||||
var1=$[ $var1-25 ]
|
||||
done
|
||||
|
||||
var1=100
|
||||
until echo $var1
|
||||
[ $var1 -eq 0 ]
|
||||
do
|
||||
echo Inside the loop: $var1
|
||||
var1=$[ $var1 - 25 ]
|
||||
done
|
||||
|
||||
|
||||
|
|
@ -0,0 +1,10 @@
|
|||
#!/bin/bash
|
||||
|
||||
# while command test
|
||||
var1=10
|
||||
while [ $var1 -gt 0 ]
|
||||
do
|
||||
echo $var1
|
||||
var1=$[ $var1 - 1 ]
|
||||
done
|
||||
|
|
@ -0,0 +1,11 @@
|
|||
#!/bin/bash
|
||||
|
||||
#testing a multicommand while loop
|
||||
|
||||
var1=10
|
||||
while echo $var1
|
||||
[ $var1 -ge 0 ]
|
||||
do
|
||||
echo 'This is inside the loop'
|
||||
var1=$[ $var1 - 1 ]
|
||||
done
|
|
@ -0,0 +1,11 @@
|
|||
#!/bin/bash
|
||||
# using double parenthesis
|
||||
|
||||
var1=10
|
||||
|
||||
if (( $var1 ** 2 > 90))
|
||||
then
|
||||
(( var2 = $var1 ** 2))
|
||||
echo "The square of $var1 if $var2"
|
||||
fi
|
||||
|
|
@ -0,0 +1,7 @@
|
|||
#!/bin/bash
|
||||
# another example of how not to use the for command
|
||||
|
||||
for test in Newada "New Hampshire"
|
||||
do
|
||||
echo "Now going to $test"
|
||||
done
|
|
@ -0,0 +1,9 @@
|
|||
#!/bin/bash
|
||||
# using pattern matching
|
||||
|
||||
if [[ $USER == r* ]]
|
||||
then
|
||||
echo "Hello $USER"
|
||||
else
|
||||
echo "Sorry, I do not know you"
|
||||
fi
|
|
@ -0,0 +1,15 @@
|
|||
#!/bin/bash
|
||||
|
||||
#changing the IFS value
|
||||
|
||||
IFS.OLD=$IFS
|
||||
IFS=$'\n'
|
||||
for entry in `cat /etc/passwd`
|
||||
do
|
||||
echo "Values in $entry -"
|
||||
IFS=:
|
||||
for value in $entry
|
||||
do
|
||||
echo " $value"
|
||||
done
|
||||
done
|
|
@ -0,0 +1,9 @@
|
|||
#!/bin/bash
|
||||
#testing compound comparisons
|
||||
|
||||
if [ -d $HOME ] && [ -w $HOME/testing ]
|
||||
then
|
||||
echo "The file exists and you can write to it"
|
||||
else
|
||||
echo "I cannot write to it"
|
||||
fi
|
|
@ -0,0 +1,20 @@
|
|||
#!/bin/bash
|
||||
|
||||
# redirecting the for output to a file
|
||||
for file in /home/tiandi/*
|
||||
do
|
||||
if [ -d "$file" ]
|
||||
then
|
||||
echo "$file is a directory"
|
||||
else
|
||||
echo "$file is a file"
|
||||
fi
|
||||
done > output.txt
|
||||
|
||||
# piping a loop to another command
|
||||
|
||||
for state in "North Dakota" Connecticut
|
||||
do
|
||||
echo "$state is next place to go"
|
||||
done | sort
|
||||
echo "This completes our travels"
|
|
@ -0,0 +1,12 @@
|
|||
#!/bin/bash
|
||||
#iterate through all the files in a directory
|
||||
for file in /home/tiandi/test/*
|
||||
do
|
||||
if [ -d "$file" ]
|
||||
then
|
||||
echo "$file is a directory"
|
||||
elif [ -f "$file" ]
|
||||
then
|
||||
echo "$file is a file"
|
||||
fi
|
||||
done
|
|
@ -0,0 +1,29 @@
|
|||
#!/bin/bash
|
||||
# testing string length
|
||||
|
||||
#-n 判断长度是否非零
|
||||
#-z 判断长度是否为零
|
||||
|
||||
val1=testing
|
||||
val2=''
|
||||
|
||||
if [ -n "$val1" ]
|
||||
then
|
||||
echo "The string $val1 is not empty"
|
||||
else
|
||||
echo "The string $val1 is empty"
|
||||
fi
|
||||
|
||||
if [ -z "$val2" ]
|
||||
then
|
||||
echo "The string $val2 is empty"
|
||||
else
|
||||
echo "The string $val2 is not empty"
|
||||
fi
|
||||
if [ -z "$val3" ]
|
||||
then
|
||||
echo "The string $val3 is empty"
|
||||
else
|
||||
echo "The string $val3 is not empty"
|
||||
fi
|
||||
|
|
@ -0,0 +1,7 @@
|
|||
#!/bin/bash
|
||||
# multiple variables
|
||||
|
||||
for (( a=1, b=10; a<=10; a++,b-- ))
|
||||
do
|
||||
echo "$a - $b"
|
||||
done
|
|
@ -0,0 +1,8 @@
|
|||
#!/bin/bash
|
||||
#testing multiple commands in the then section
|
||||
testuser=tiandi
|
||||
if grep $testuser /etc/passwd
|
||||
then
|
||||
echo The bash files from user $testuser are:
|
||||
ls -a /home/$testuser/.b*
|
||||
fi
|
|
@ -0,0 +1,9 @@
|
|||
#!/bin/bash
|
||||
#testing string equality
|
||||
|
||||
testuser=tiandi
|
||||
|
||||
if [ $USER = $testuser ]
|
||||
then
|
||||
echo "Welcome $testuser"
|
||||
fi
|
|
@ -0,0 +1,2 @@
|
|||
#!/bin/bash
|
||||
|
|
@ -0,0 +1,20 @@
|
|||
#!/bin/bash
|
||||
# checking if a directory or a file exists
|
||||
|
||||
if [ -e $HOME ]
|
||||
then
|
||||
echo "OK on the directory.now to check the file"
|
||||
#checking if a file exists
|
||||
if [ -e $HOME/testing ]
|
||||
then
|
||||
#the file exists,append data to it
|
||||
echo "Appending date to existing file"
|
||||
date >> $HOME/testing
|
||||
else
|
||||
#the file is not exists,create a new file
|
||||
echo "Creating a new file"
|
||||
date > $HOME/testing
|
||||
fi
|
||||
else
|
||||
echo 'Sorry. you do not have a $HOME directory'
|
||||
fi
|
|
@ -0,0 +1,11 @@
|
|||
#!/bin/bash
|
||||
# look before you leap
|
||||
|
||||
if [ -d $HOME ]
|
||||
then
|
||||
echo "Your home directory exists"
|
||||
cd $HOME
|
||||
ls -a
|
||||
else
|
||||
echo "There is a problem with your HOME direcotry"
|
||||
fi
|
|
@ -0,0 +1,12 @@
|
|||
#!/bin/bash
|
||||
#正确使用大于小于号
|
||||
|
||||
val1=baseball
|
||||
val2=hocky
|
||||
|
||||
if [ $val1 \> $val2 ]
|
||||
then
|
||||
echo "$val1 is greater than $val2"
|
||||
else
|
||||
echo "$val1 is less than $val2"
|
||||
fi
|
|
@ -0,0 +1,12 @@
|
|||
#!/bin/bash
|
||||
#test命令中,大小字母会被当成小于小写字符,而在sort中,小写字母会先出现,test使用标准的ASCII排序,sort使用本地化语言设置进行排序,对于英语,本地化设置制定了排序顺序中小写字母出现在大写字母之前
|
||||
|
||||
var1=Testing
|
||||
var2=testing
|
||||
|
||||
if [ $val1 \> $val2 ]
|
||||
then
|
||||
echo '$val1 is greater than $val2'
|
||||
else
|
||||
echo '$val1 is less than $val2'
|
||||
fi
|
|
@ -0,0 +1,6 @@
|
|||
#!/bin/bash
|
||||
|
||||
for test in I don\'t know if "this'll" work
|
||||
do
|
||||
echo "word:$test"
|
||||
done
|
|
@ -0,0 +1,7 @@
|
|||
#!/bin/bash
|
||||
|
||||
# basic for command
|
||||
for test in Alabama Alaska Arizona
|
||||
do
|
||||
echo The next state is $test
|
||||
done
|
|
@ -0,0 +1,8 @@
|
|||
#!/bin/bash
|
||||
|
||||
# another example of how not to use the for command
|
||||
|
||||
for test in I don't know if this'll work
|
||||
do
|
||||
echo "word:$test"
|
||||
done
|
|
@ -0,0 +1,14 @@
|
|||
#!/bin/bash
|
||||
# 大于小于号必须转义,否则shell会将它们当做重定向符号而把字符串值当做文件名处理
|
||||
# 大于小于号顺序和sort命令所采用的有所不同
|
||||
# mis-using string comparisons
|
||||
|
||||
val1=baseball
|
||||
val2=hockey
|
||||
|
||||
if [ $val1 > $val2 ]
|
||||
then
|
||||
echo "$val1 is greater than $val2"
|
||||
else
|
||||
echo "$val1 is less than $val2"
|
||||
fi
|
Loading…
Reference in New Issue