First script file
Copy Code code as follows:
#!/bin/bash
echo "This are my I-A-bash code!"
Exit 0
redirect Symbols and mathematical calculations
Copy Code code as follows:
#!/bin/bash
Echo-n "The time and date are:"
Date
value1=100 #等号前后不允许出现空格
value2= $value 1
Echo-n "Value1="
echo $value 1
Echo-n "Value2="
Echo $value 2
Ls-l | Sort > OUT.txt #管道符号 (|) and redirect Output symbols >
Ls-l >> out.txt #重定向追加输出符号 >>
Echo-n "Wc<out.txt:"
WC < OUT.txt #重定向输入符号 <
echo "Sort<<eof ... EOF "
Sort << EOF #内置输入重定向 <<
' Date '
Eof
#数学计算
Echo-n "Expr for calculation: 1+5="
Expr 1+5
Echo-n "Using square brackets for calculation: 1+5="
Echo $[1+5]
echo "uses the BC calculator for floating-point operations"
var1=100
var2=200
Var3= ' echo ' scale=4 $var 1/$var 2 "| BC '
echo "$var 1/$var 2 = $var 3"
var4=71
Var5= ' bc<<eof
Scale=4
a1= ($var 1* $var 2)
b1= ($var 3* $var 4)
A1+b1
EOF '
echo "var5= $var 5"
Exit 0
Using the test command
Copy Code code as follows:
#!/bin/bash
#使用test命令
var1=10
var2=100
If [$var 1-gt $var 2]
Then
echo "Var1 Grate Var2"
Else
echo "Var2 Grate var1"
Fi
#只能比较整数
Test_user=hanxi
if [$USER = $test _user]
Then
echo "Welcome $test _user"
Fi
Str1=hanxi
Str2=hanxi
If [$str 1 \> $str 2]
Then
echo "$str 1 > $str 2"
Else
echo "$str 1 < $str 2"
Fi
If [-N $str 1]
Then
echo "The string ' $str 1 ' is not empty"
Else
echo "The string ' $str 1 ' is empty"
Fi
#检查文件目录
If [-D $HOME]
Then
echo "Your home dir exists"
CD $HOME
Ls-a
Else
echo "There ' s a problem with your home dir"
Fi
Pwfile=/etc/shadow
If [f $pwfile]
Then
If [-R $pwfile]
Then
Tail $pwfile
Else
echo "Sorry, I ' m unable to reas the $pwfile file"
Fi
Else
echo "Sorry, the file $pwfile doesn ' t exist"
Fi
if [[$USER = = h*]]
Then
echo "Hello $USER"
Else
echo "Sorry, I don ' t know you"
Fi
Loop statement
Copy Code code as follows:
#!/bin/bash
For file in/home/hanxi/*
Todo
If [-D "$file]"
Then
echo "$file is a directory"
elif [F "$file]"
Then
echo "$file is a file"
Fi
Done
var1=10
While [$var 1-GT 0]
Todo
echo $var 1
var1=$[$var 1-1]
Done
var1=100
Until [$var 1-eq 0]
Todo
echo $var 1
var1=$[$var 1-25]
Done
#文件数据的循环
Ifsold= $IFS
ifs=$ ' \ n '
For entry in ' CAT/ETC/PASSWD '
Todo
echo "Values in $entry-"
Ifs=:
For value in $entry
Todo
echo "$value"
Done
Done | More
For file in/home/hanxi/*
Todo
If [-D "$file]"
Then
echo "$file is directory"
Elif
echo "$file is a file"
Fi
Done > Output.txt
Read parameters
Copy Code code as follows:
#!/bin/bash
Name= ' basename $ '
echo the Commane entered is: $name
c_args=$#
echo Count args: $c _args
#取最后一个参数
echo the last parameter is ${!#}
echo All parameter: $*
echo All parameter: $@
Count=1
For param in "$@"
Todo
echo "\$@ parameter # $count = $param"
count=$[$count + 1]
Done
#getopts
While Getopts:ab:c opt
Todo
Case "$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
Shift $[$OPTIND-1]
Count=1
For param in "$@"
Todo
echo "Parameter $count: $param"
count=$[$count + 1]
Done
Read-p ' Please enter your age: ' Age
echo Age: $age
If read-t 5-p "Please enter your name:"
Then
echo "HELLP $name, Welcome to my Script"
Else
Echo
echo "Sorry, too slow!"
Fi
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,good bye
exit;;
Esac
Echo ' This is the ' end of the script
Read-s-P "Enter Your password:" Pass
Echo
echo "Is your password really $pass?"
#读取文件
Count=1
Cat For.txt | While Read line
Todo
echo "line $count: $line"
count=$[$count +1]
Done
echo "Finished processing the file"
REDIRECT File descriptor
Copy Code code as follows:
#!/bin/bash
#永久重定向
EXEC 9>&2
EXEC 2>testerror
echo "This'll in Testerror" >&2
EXEC 2<&9
EXEC 9<&0
EXEC 0<testin
Count=1
While Read line
Todo
echo "Line # $count: $line"
count=$[$count + 1]
Done
EXEC 0<&9
#重定向文件描述符
EXEC 3>&1
EXEC 1>testout
echo "This should store in the output file"
echo "along with this line."
EXEC 1>&3
echo "Now things should is back to Nomarl"
EXEC 4<&0
EXEC 0<testin
Count=1
While Read line
Todo
echo "Line # $count: $line"
count=$[$count + 1]
Done
EXEC 0<&4
Read-p "Are You do Now" answer
Case $answer in
Y|y) echo "Goodbye";;
N|n) echo "Continue ...";
Esac
#创建读写文件描述符
EXEC 8<> testfile
Read Line <&8
echo "Read: $line"
echo "This is a test line" >&8
#关闭文件描述符
EXEC 8>&-
#列出文件描述服
# '/usr/sbin/lsof-a-P $$ ' |more
#禁止命令输出
#2 >/dev/null
#创建本地临时文件
tempfile= ' mktemp test. XXXXXX '
EXEC 4> $tempfile
echo "This is the" ">&3"
EXEC 4>&-
Create temporary files #在/temp
Tmpfile= ' mktemp-t tmp. XXXXXX '
echo "The temp file is located at: $tempfile"
Cat $tempfile
Rm-f $tempfile
#创建临时文件夹
Tmpdir= ' mktemp-d dir. XXXXXX '
CD $tmpdir
tempfile1= ' Mktemp temp. XXXXXX '
Ls-l
Cd..
#记录消息
A= ' date | Tee testfile;\
Cat testfile;\
Date | Tee-a testfile;\
Cat Testfile '
Signal Processing
Copy Code code as follows:
#!/bin/bash
#信号处理
Trap "Echo ' Get a sign '" SIGINT sigterm
Trap "Echo Byebye" EXIT
echo "This are a test program"
Count=1
While [$count-le 10]
Todo
echo "Loop # $count"
Sleep 10
count=$[$count +1]
Done
echo "This is the" ' The ' Test program '
trap-exit# Removal capture
#后台牧师运行
#./test6.sh &
#不使用终端的情况下运行脚本
#nohup./test6.sh &
#查看作业
#jobs
#重新启动作业
#bg 2 (Job serial number)//Backstage
#fg 2//Front Desk
#优先级
#nice-N/test6.sh
#renice 10-p 25904 (process number)
#预计时间运行at命令
#at-F test6.sh 20:00
#batch命令, the system runs at an average load of less than 0.8 and can set the time, better than the AT command
#corn表格可以设定循环运行, Format:
#min hour dayofmonth Month DayOfWeek command
#每个月第一天运行:
#12 * * 1 command
#每个月最后一天运行:
#12 * * If [' Date +%d =d tommorrow ' = 01]; then; Command
Use of functions
Copy Code code as follows:
#!/bin/bash
#函数
#使用返回值
function func1
{
Read-p "Enter A value:" Value
Echo $[$value * 2]
}
result= ' func1 '
echo "The new value is $result"
#传递参数
function Func2
{
Echo $[$1+$2]
}
Result= ' Func2 2 2 '
echo "The new result is $result"
#局部变量, recursive
function func3
{
If [$1-eq 1]
Then
Echo 1
Else
Local temp=$[$1-1]
Local result= ' func3 $temp '
echo $[$result *$1]
Fi
}
Read-p "Enter Value:" Value
result= ' func3 $value '
echo "The factorial of $value is: $result"
#调用当前目录下到函数库
#. ./myfuncs
