1 ps -ef 显示正在执行的进程，pid 等信息
UID PID PPID C STIME TTY TIME CMD
root 1 0 0 03:45 ? 00:00:02 init [5]
root 2 1 0 03:45 ?
00:00:00 [migration/0]
root 3 1 0 03:45 ? 00:00:00 [ksoftirqd/0]
root 4 1 0 03:45 ? 00:00:00 [events/0]
root 5 1 0 03:45 ?
00:00:00 [khelper]
root 6 1 0 03:45 ? 00:00:00 [kthread]
root 9 6 0 03:45 ?
00:00:00 [kblockd/0]
root 10 6 0 03:45 ? 00:00:00 [kacpid]
2 df -h 可读显示磁盘空间 M是兆
Filesystem Size Used Avail Use% Mounted on
/dev/sda2 18G 5.0G 12G 31% /
/dev/sda1 289M 16M 258M 6% /boot
tmpfs 506M 0 506M 0% /dev/shm
3 借助df命令，能够方便地了解磁盘是否已空间不足，系统管理员须要了解空间不足时该怎么办。
我们能够使用du命令 ，du命令显示特定文件夹的磁盘使用情况，这是推断系统是否存在磁盘
占用大户的快捷方法。
du , du -h（显示M。G单位） ,du -c （汇总），du -s（汇总全部。仅仅显示一个）
du [ -a | -s ] [ -k ] [ -m ] [ -g ][ -l ] [ -r ] [ -x ] [ -H | -L ][ File ... ]
8.0K ./test_flume/.flumespool
24K ./test_flume
8.0K ./mnt
58M ./awk
28K ./shell
18M ./spark
76M .
4 sort （排序） sort file.txt
默认按字符排序
数字排序 sort -n file.txt
sort -n file2
0
2
3
5
6
7
9
17
sort -M file3.txt (依照月份排序)
sort -t ‘:‘ -k 3 -n /etc/passwd 按指定分隔符‘:" 第三个字段进行排序 按数字排序的
du -sh * | sort -nr 按空间占用从大到小 排序 包含目录和文件 r是指降序排列
5 gzip ：用于压缩文件
gzip 2.sh
gzip file*
gzip -r test1 test2 压缩2个文件
tar -cvf my.tar my.sh tar压缩
tar -zxvf filename.tgz
7 打印环境变量
printenv
bash
test=testing
echo $test
7 finger llisc
/usr/sbin/groupadd shared
/usr/sbin/usermod -G shared test
文件权限表 755
chmod o+r newfile
将条目读取加入到不论什么人
chmod u-x newfile
将条目山下湖用户拥有的运行权限
chmod u+x newfile
chown 改动用户文件拥有者 和所在组
9 shell
rpm -qa | sort | more
if 表达式 返回0 运行成功
then
fi
if test [ condition ]
for var in Li72 Alibaba taobao Newbatilr
do
echo the state $test
done
使用转移字符反斜杠符合来转移单引號
使用双引號来定义单引號的值
#!/bin/bash
for file in /home/bigdata/test/* /home/li75/
do
if [ -d "$file" ]
then
echo "$file is a directory "
elif [ -f "$file" ]
then
echo "$file is a file "
fi
done
#!/bin/bash
for(( i=1; i<= 10; i++))
do
echo " The next number is $i"
done
#!/bin/bash
var1=10
while [ $var1 -gt 0 ]
do
echo $var1
var1=$[ $var1 - 1 ]
done
#!/bin/bash
var1=100
until [ $var1 -eq 0 ]
do
echo $var1
var1 =$[ $var1 -25 ]
done
#!/bin/bash
for((a =1; a<=3; a++))
do
echo "starting loop $a:"
for((b=1;b<=3;b++))
do
echo " inside loop: $a*$b "
done
done
break
contince
#!/bin/bash
for(( a=1; a<4 ;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 > test.txt 重定向到一个文件
| sort 排序
參数
位置參数
$0 为为程序名称
$1 为第一个參数
$2 为第二个參数
$3 为第三个參数
#!/bin/bash
factorial=1
for((number =1;number<= $1;number++))
do
factorial=$[ $factorial * $number ]
done
echo The factorial of $1 is $factorial
name =` basename $0`
获取执行shell 脚本名称
if [ -n "$1" ]
推断有没有传入參数
if [ $# <5 ]
推断传入參数个数
获取最后一个參数的值
params =$#
echo parm : $params
或者
The last paramer ${!#}
$* 把全部的參数当作一个參数
$@ 把全部參数当作字符串 分开处理
#!/bin/bash
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";;
*) echo "$1 is not an option";;
esac
shift
done
#!/bin/bash
echo -n ‘Enter your name :"
read name
echo "Hello $name, welcome to my prorram ."
#!/bin/bash
read -p "Please enter your age :" age
days =$[ $age * 365 ]
echo " That makes you over $days days old !"
ls -al test test22 test3 badtest &>test7
#!/bin/bash
echo "This is an error " >&2
echo "This is normal output "
#!/bin/bash
exec 1>testout
echo "This is a test of redirting all output"
echo "without having to redirect every line "
#!/bin/bash
exec 2>testerror
echo "This is the start of the script"
echo "now reidirecting all output to another "
exec 1>testout2
echo "This putput should go to the "
echo "but shis should go to testerror file >&2
#!/bin/bash
exec 0<testfile2
count=1
while read line
do
echo "Line #$count :$line"
count=$[ $count +1 ]
done
lsof -a -p $$ -d 0,1,2
重定向到空文件
ls -al >/dev/null
cat /dev/null > testfile
同一时候记录文件和打印到屏幕
date | tee testfile
追加数据
date | tee -a testfile
kill -9 进程id
#!/bin/bash
trap "echo HaHa " SIGINT SIGTEERM
echo "THis is a test program "
count=1
while [ $count -le 10 ]
do
echo "Loop #$count"
sleep 10
count=$[ $count +1 ]
done
echo "This is the end of test program "
把命令在后台执行用 &
sh 37.sh &
ps au
有时须要从终端启动会话，然后让脚本在结束之前以后台模式执行，即使退出终端会话有时如此
能够用nohup
jobs
jobs -r
jobs -s
jobs -l
nice 设置优先级
nice -n 10 sh 38.sh >test4out &
at 命令
batch 命令
cron 表格
#!/bin/bash
time=`date +%T`
echo "This script ran at $time "
echo "This is the end of the script">&2
15 10 * * * command
查看登陆用户配置的定时任务
crontab -l
编辑任务
corntab -e
#!/bin/bash
function func1 {
echo ‘This is an example of a function"
}
count=1
while [ $count -le 5 ]
do
func1
count=$[ $count +1 ]
done
echo "This is the end of the loop"
func1
echo "Now this is the end of the script "
函数的返回值
$?
#!/bin/bash
func1(){
echo "trying to display a non"
ls -ls 41.sh
}
echo "testing the function:"
func1
echo "The exit status is :$?
"
#!/bin/bash
function db1 {
read -p "Enter a value :" value
echo "doubling the value "
return $[ $value * 2 ]
}
db1
echo "The new value is $?"
函数返回值
#!/bin/bash
function db1{
read -p "Enter a value :" value
echo $ [ $value *2 ]
}
result=‘db1‘
echo ‘The new value is $result"
提供函数文件
能够用source 命令或称（点操作符）将现有的库函数引进.bashrc中
source /home/li72/libraries/myfuncs
. /home/li72/libraries/myfuncs
function addem {
echo $[ $1 +$2 ]
}
function multem {
echo $[ $1 * $2 ]
}
function divem {
if [ $2 -ne 0 ]
then
echo $[ $1 /$2 ]
else
echo -1
fi
}
#!/bin/bash
. ./myfuncs
result=`addem 10 16`
echo "The result is $result"
.bashrc 每次启动shell 都会检查该文件 ，在已有文件的末尾加入自己定义函数
. /home/bigdata/test/shell/myfuncs
文本处理
sed luinx 编辑替换
gawk
echo "This is a test " | sed ‘s/test/big test/‘
cat>dog.txt
The quick brown fox jumps over the lazy dog .
The quick brown fox jumps over the lazy dog .
The quick brown fox jumps over the lazy dog .
The quick brown fox jumps over the lazy dog .
The quick brown fox jumps over the lazy dog .
sed ‘s/dog/cat/‘ dog.txt
The quick brown fox jumps over the lazy cat .
The quick brown fox jumps over the lazy cat .
The quick brown fox jumps over the lazy cat .
The quick brown fox jumps over the lazy cat .
The quick brown fox jumps over the lazy cat .
sed -e ‘
> s/brown/green/
> s/fox/elephant/
> s/dog/cat/‘ dog.txt
The quick green elephant jumps over the lazy cat .
The quick green elephant jumps over the lazy cat .
The quick green elephant jumps over the lazy cat .
The quick green elephant jumps over the lazy cat .
The quick green elephant jumps over the lazy cat .
从文件读取编辑器命令
cat>script
s/brown/green/
s/fox/elephant/
s/dog/cat/
sed -f script dog.txt
The quick green elephant jumps over the lazy cat .
The quick green elephant jumps over the lazy cat .
The quick green elephant jumps over the lazy cat .
The quick green elephant jumps over the lazy cat .
The quick green elephant jumps over the lazy cat .
cat>script2
{print $5 "‘s userid is " $1 }
加入用户
useradd xuhui
改动password
usermod -p xuhui xuhui
查看password文件
tail -l /etc/shadow
cd - 返回上一个訪问的文件夹
查找文件命令
find [路径] [选项] [操作]
find . -name ‘test*‘ 查找 文件名为 test开头的
find . -mtime -90 -print 查找更改时间在90天内的文件
grep [选项] [模式] [文件]
在wodl.txt 找World单词
grep -w ‘World‘ wodl.txt
