#cd ~ 回到当前用户的家目录
[root@VM_168_102_centos etc]# pwd/etc //当前所在目录[root@VM_168_102_centos etc]# cd ~ //回到当前用户家木里[root@VM_168_102_centos ~]# pwd/root //当前用户家目录[root@VM_168_102_centos ~]# su wanghan [wanghan@VM_168_102_centos rott]$ cd ~ //回到当前用户家木里[wanghan@VM_168_102_centos ~]$ pwd /home/wanghan //当前用户家目录[wanghan@VM_168_102_centos ~]$
#cd - 回到上一次所在目录
[wanghan@VM_168_102_centos ~]$ cd /etc //切换到/etc目录[wanghan@VM_168_102_centos etc]$ cd /tmp //从/etc目录切换到/tmp目录[wanghan@VM_168_102_centos tmp]$ cd - //从当前/tmp回到上一次所在目录/etc //回到了/etc[wanghan@VM_168_102_centos etc]$ cd - //再从/etc回到上一次所在目录/tmp //回到了/tmp[wanghan@VM_168_102_centos tmp]$
#pwd命令：查看当前工作目录的完整路径
[wanghan@VM_168_102_centos /]$ pwd/[wanghan@VM_168_102_centos /]$ cd /etc[wanghan@VM_168_102_centos etc]$ pwd/etc[wanghan@VM_168_102_centos etc]$
#mkdir命令：用来创建指定的名称的目录，要求创建目录的用户在当前目录中具有写权限，并且指定的目录名不能是当前目录中已有的目录。
mkdir [选项] 目录…
[wanghan@VM_168_102_centos tmp]$ lsagent_cmd.sock ap_1002.pid ap_1004.pid ap_1005.pid ap_1007.pid ap_1008.pid ap_1014.pid[wanghan@VM_168_102_centos tmp]$ mkdir /tmp/test[wanghan@VM_168_102_centos tmp]$ lsagent_cmd.sock ap_1002.pid ap_1004.pid ap_1005.pid ap_1007.pid ap_1008.pid ap_1014.pid test
mkdir –p 目录…
[wanghan@VM_168_102_centos tmp]$ lsagent_cmd.sock ap_1002.pid ap_1004.pid ap_1005.pid ap_1007.pid ap_1008.pid ap_1014.pid test[wanghan@VM_168_102_centos tmp]$ mkdir /tmp/wanghan/testmkdir: cannot create directory `/tmp/wanghan/test': No such file or directory[wanghan@VM_168_102_centos tmp]$ mkdir -p /tmp/wanghan/test[wanghan@VM_168_102_centos tmp]$ lsagent_cmd.sock ap_1002.pid ap_1004.pid ap_1005.pid ap_1007.pid ap_1008.pid ap_1014.pid test wanghan[wanghan@VM_168_102_centos tmp]$ ls wanghantest[wanghan@VM_168_102_centos tmp]$
若创建的路径中有尚不再存的目录即可按照路径全部创建
mkdir –v 目录…
[wanghan@VM_168_102_centos tmp]$ mkdir -pv /tmp/a/b/c/d/e/f/abcdmkdir: created directory `/tmp/a'mkdir: created directory `/tmp/a/b'mkdir: created directory `/tmp/a/b/c'mkdir: created directory `/tmp/a/b/c/d'mkdir: created directory `/tmp/a/b/c/d/e'mkdir: created directory `/tmp/a/b/c/d/e/f'mkdir: created directory `/tmp/a/b/c/d/e/f/abcd'
显示创建目录过程的详细信息
#rmdir命令：删除已空的目录
[wanghan@VM_168_102_centos tmp]$ lsa agent_cmd.sock ap_1002.pid ap_1004.pid ap_1005.pid ap_1007.pid ap_1008.pid ap_1014.pid ceshi test wanghan[wanghan@VM_168_102_centos tmp]$ ls testtest_1[wanghan@VM_168_102_centos tmp]$ rmdir /tmp/test rmdir: failed to remove `/tmp/test': Directory not empty //该目录非空[wanghan@VM_168_102_centos tmp]$ rmdir /tmp/test/test_1[wanghan@VM_168_102_centos tmp]$ ls test[wanghan@VM_168_102_centos tmp]$ rmdir /tmp/test[wanghan@VM_168_102_centos tmp]$ lsa agent_cmd.sock ap_1002.pid ap_1004.pid ap_1005.pid ap_1007.pid ap_1008.pid ap_1014.pid ceshi wanghan
#shell中的引用
‘ ’：强引用，变量替换不会进行
[wanghan@VM_168_102_centos tmp]$ num=123[wanghan@VM_168_102_centos tmp]$ echo $num123[wanghan@VM_168_102_centos tmp]$ echo '$num'$num
“ ”：若引用，能够执行变量替换
[wanghan@VM_168_102_centos tmp]$ num=456[wanghan@VM_168_102_centos tmp]$ echo numnum[wanghan@VM_168_102_centos tmp]$ echo "num"num[wanghan@VM_168_102_centos tmp]$
· ·：命令替换，引用命令的执行结果；命令替换的另外一符号：$(命令)；
[wanghan@VM_168_102_centos tmp]$ echo ls /tmpls /tmp[wanghan@VM_168_102_centos tmp]$ echo `ls /tmp`a agent_cmd.sock ap_1002.pid ap_1004.pid ap_1005.pid ap_1007.pid ap_1008.pid ap_1014.pid ceshi wanghan
结合使用：
[wanghan@VM_168_102_centos tmp]$ echo $testtmp[wanghan@VM_168_102_centos tmp]$ echo "This is $test"This is tmp[wanghan@VM_168_102_centos tmp]$ echo `ls /$test` a agent_cmd.sock ap_1002.pid ap_1004.pid ap_1005.pid ap_1007.pid ap_1008.pid ap_1014.pid ceshi wanghan[wanghan@VM_168_102_centos tmp]$ echo "/tmp:`ls /$test`"/tmp:aagent_cmd.sockap_1002.pidap_1004.pidap_1005.pidap_1007.pidap_1008.pidap_1014.pidceshiwanghan
#创建一个一当前日期时间创建一个目录
[wanghan@VM_168_102_centos tmp]$ date=`date +%Y-%m-%d-%H%M%S`[wanghan@VM_168_102_centos tmp]$ mkdir -pv /tmp/$datemkdir: created directory `/tmp/2014-08-04-212053'[wanghan@VM_168_102_centos tmp]$ ls2014-08-04-212053 a agent_cmd.sock ap_1002.pid ap_1004.pid ap_1005.pid ap_1007.pid ap_1008.pid ap_1014.pid ceshi wanghan[wanghan@VM_168_102_centos tmp]$
#history命令：查看在当前shell进程的保存在缓冲区中的执行过的命令列表，当shell退出时缓冲区的命令会自动化保存至当前用户的家目录中的.bash_history文件中。
[root@VM_168_102_centos ~]# su wanghan[wanghan@VM_168_102_centos rott]$ history 1 exit 2 history[wanghan@VM_168_102_centos rott]$ whoroot pts/0 Aug 4 19:11 (222.36.253.150)[wanghan@VM_168_102_centos rott]$ pwd/root[wanghan@VM_168_102_centos rott]$ history 1 exit 2 history 3 who 4 pwd 5 history[wanghan@VM_168_102_centos rott]$ cat /home/wanghan/.bash_historyexit[wanghan@VM_168_102_centos rott]$ exitexit[root@VM_168_102_centos ~]# su wanghan[wanghan@VM_168_102_centos rott]$ cat /home/wanghan/.bash_historyexithistorywhopwdhistorycat /home/wanghan/.bash_historyexit[wanghan@VM_168_102_centos rott]$
！#：通过命令历史列表中的命令编号引用并执行第#条命令
[wanghan@VM_168_102_centos rott]$ history 1 exit 2 history 3 who 4 pwd 5 history 6 cat /home/wanghan/.bash_history 7 exit 8 cat /home/wanghan/.bash_history 9 history 10 history who 11 history pwd 12 history 13 history who 14 exit 15 history 16 who 17 history[wanghan@VM_168_102_centos rott]$ !3whoroot pts/0 Aug 4 19:11 (222.36.253.150)[wanghan@VM_168_102_centos rott]$！-#：通过命令历史列表中的命令编号引用并执行倒数第#条命令
[wanghan@VM_168_102_centos rott]$ history 1 exit 2 history 3 who 4 pwd 5 history 6 cat /home/wanghan/.bash_history 7 exit 8 cat /home/wanghan/.bash_history 9 history 10 history who 11 history pwd 12 history 13 history who 14 exit 15 history 16 who 17 history 18 who 19* 20 history[wanghan@VM_168_102_centos rott]$ !-3whoroot pts/0 Aug 4 19:11 (222.36.253.150)[wanghan@VM_168_102_centos rott]$
！！：执行上一次历史命令
[wanghan@VM_168_102_centos rott]$ pwd/root[wanghan@VM_168_102_centos rott]$ !!pwd/root[wanghan@VM_168_102_centos rott]$ !!pwd/root
! string：执行命令历史列表中最近一次以string开头的命令
[wanghan@VM_168_102_centos rott]$ whatisusage: whatis keyword ...[wanghan@VM_168_102_centos rott]$ whoroot pts/0 Aug 4 19:11 (222.36.253.150)[wanghan@VM_168_102_centos rott]$ !wwhoroot pts/0 Aug 4 19:11 (222.36.253.150)[wanghan@VM_168_102_centos rott]$
！ $：引用上一个命令的最后一个参数，快捷键：Esc .
[wanghan@VM_168_102_centos etc]$ cd /tmp[wanghan@VM_168_102_centos tmp]$ ls /!$ls //tmp2014-08-04-212053 a agent_cmd.sock ap_1002.pid ap_1004.pid ap_1005.pid ap_1007.pid ap_1008.pid ap_1014.pid ceshi wanghan
history –c：清空当前缓存中的历史记录
[wanghan@VM_168_102_centos tmp]$ history 1 who 2 pwd 3 history[wanghan@VM_168_102_centos tmp]$ history -c[wanghan@VM_168_102_centos tmp]$ history 1 history
history –d #：删除与命令历史列表中命令编号相对应的命令记录
[wanghan@VM_168_102_centos tmp]$ history 1 who 2 pwd 3 history[wanghan@VM_168_102_centos tmp]$ history -d 1[wanghan@VM_168_102_centos tmp]$ history 1 pwd 2 history 3 history -d 1 4 history[wanghan@VM_168_102_centos tmp]$
history -a：追加当前历史记录保存至命令历史文件中
[wanghan@VM_168_102_centos rott]$ cat /home/wanghan/.bash_historyexit[wanghan@VM_168_102_centos rott]$ history 1 exit 2 cat /home/wanghan/.bash_history 3 history[wanghan@VM_168_102_centos rott]$ whoroot pts/0 Aug 4 19:11 (222.36.253.150)[wanghan@VM_168_102_centos rott]$ pwd/root[wanghan@VM_168_102_centos rott]$ histroy -abash: histroy: command not found[wanghan@VM_168_102_centos rott]$ history -a[wanghan@VM_168_102_centos rott]$ cat /home/wanghan/.bash_historyexitcat /home/wanghan/.bash_historyhistorywhopwdhistroy -ahistory -a[wanghan@VM_168_102_centos rott]$
命令历史相关的环境变量：
HISTSIZE：命令历史中可以保存的命令个数
[root@VM_168_102_centos ~]# echo $HISTSIZE1000
HISTFILESIZE：命令文件中可以保存的命令个数
[root@VM_168_102_centos ~]# echo $HISTFILESIZE1000
HISTFILE：命令历史文件
[root@VM_168_102_centos ~]# echo $HISTFILE/root/.bash_history
HISTCONTROL：控制命令历史的生成
[root@VM_168_102_centos ~]# echo $HISTCONTROLignoredups
ignoredups：忽略重复记录的命令，连续相同的命令才算重复
[root@VM_168_102_centos ~]# history 1 history[root@VM_168_102_centos ~]# whoroot pts/0 Aug 4 19:11 (222.36.253.150)[root@VM_168_102_centos ~]# whoroot pts/0 Aug 4 19:11 (222.36.253.150)[root@VM_168_102_centos ~]# history 1 history 2 who 3 history[root@VM_168_102_centos ~]# whoroot pts/0 Aug 4 19:11 (222.36.253.150)[root@VM_168_102_centos ~]# history 1 history 2 who 3 history 4 who 5 history[root@VM_168_102_centos ~]#
ignorespace：不记录以空白字符开头的命令
[root@VM_168_102_centos ~]# echo $HISTCONTROLignoredups[root@VM_168_102_centos ~]# HISTCONTROL=ignorespace[root@VM_168_102_centos ~]# echo $HISTCONTROLignorespace[root@VM_168_102_centos ~]# history 1 history 2 echo $HISTCONTROL 3 HISTCONTROL=ignorespace 4 echo $HISTCONTROL 5 history[root@VM_168_102_centos ~]# who root pts/0 Aug 4 19:11 (222.36.253.150)[root@VM_168_102_centos ~]# pwd/root[root@VM_168_102_centos ~]# history 1 history 2 echo $HISTCONTROL 3 HISTCONTROL=ignorespace 4 echo $HISTCONTROL 5 history 6 history[root@VM_168_102_centos ~]#
ignoreboth：同时具有ignoredups和ignorespace的特性
shell中的变量赋值：
变量名=值
[root@VM_168_102_centos ~]# num=123[root@VM_168_102_centos ~]# echo $num123
注意：变量在赋值时不能使用$
变量名只能包含字母、数字和下划线，而且不能以数字开头
变量名区别大小写
[root@VM_168_102_centos ~]# num=123[root@VM_168_102_centos ~]# echo $NUM[root@VM_168_102_centos ~]# echo $num123