Linux基本操作实验（5）
平常在LINUX上进行操作，操作最多接触的就是SHELL，而在SHELL中最多接触的就是文件，我们通常需要不停的查找、查看、编辑等。文件在LINUX中命名是有一定规则的。如果快速的定位到一个文件名。或者说模糊匹配一个文件名，应该怎么做。比喻说我们只记得曾经写过一个search****fILE.c 这个文件，但不知道具体的名字，那这个时候需要用到的知道，就是模糊匹配，在LINUX中对文件名有通配符和元字符之说，通配符和元字符与正则表达式中相关符号可能相近，但表示的意义是不一样，需要注意。这里总结如下：
| * | 匹配文件名中的任何字符串，包括空字符串，或者当前目录下所有文件 | ls app* ls *.doc ls cl*.sed cd cron.w* |
列出所有以app开头的文件 列出以.doc结尾的所有文件 列出以cl中间任意字符（个数不定）并以.sed结尾的字符 进入以cron.w*开头的目录，注意只能一个，如果多个会失败。 |
| ？ | 匹配文件名中的单个字符串 | ls ??R* ls conf??.log ls f??*s |
列出R前有任意两个字符的，R后有任意多个字符的文件 列出以conf开头，中间两个任意字 符，后以.log结尾 列出以f开头,中间任意两个字符，后接任意多个字符并以s结尾的文件 |
| [...] | 匹配[]中包含的任意字符 | ls [io]* ls log.[0-9]* |
|
| [!...] | 不匹配[]中！后的任意字符 | ls log.[!0-9]* |
这些通配符与正则中有一些不一样，需要注意。
[root@windriver-machine shtest]# ls *3*
1234 1234.txt
123abc:
123abc.txt
[root@windriver-machine shtest]# ls *abc
123abc.txt
[root@windriver-machine shtest]# ls *abc*
123abc.txt
[root@windriver-machine shtest]# ls -latr *abc*
total 8
-rwxr-xr-x 1 windriver windriver 0 2011-08-06 21:24 123abc.txt
drwsr-sr-x 2 windriver windriver 4096 2011-08-06 21:24 .
drwxrwxr-x 3 windriver windriver 4096 2011-08-07 02:15 ..
[root@windriver-machine shtest]# ll
total 28
lrwxrwxrwx 1 root root 8 2011-08-06 22:07 1234 -> 1234.txt
-rw-r--r-- 1 root root 0 2011-08-07 01:43 1234.txt
drwsr-sr-x 2 windriver windriver 4096 2011-08-06 21:24 123abc
-rw-rw-r-- 2 windriver windriver 74 2011-08-06 22:11 errors
-rwxrwxr-x 1 windriver windriver 120 2011-08-06 01:44 ex1.sh
-rw-rw-r-- 2 windriver windriver 74 2011-08-06 22:11 newerr
-rw-rw-r-- 1 windriver windriver 1640 2011-08-06 19:13 output
-rw-r--r-- 1 root root 31 2011-08-07 02:14 testoutput
-rw-r--r-- 1 root root 169 2011-08-07 02:15 testoutput2
[root@windriver-machine shtest]# ll -d *abc*
drwsr-sr-x 2 windriver windriver 4096 2011-08-06 21:24 123abc
[root@windriver-machine shtest]#
[root@windriver-machine shtest]# ls ????r?
errors newerr
[root@windriver-machine shtest]# ls [e]*
errors ex1.sh
[root@windriver-machine shtest]# ls [0-9][0-9][0-9][A-Za-z]*
123abc.txt
[root@windriver-machine shtest]#
学习了如何模糊匹配文件，这里我们继续学习几个常用的文件操作命令。
【1】echo echo可以向屏幕输出。 echo [-e] [-n] STRING 其中STRING是要输出的字符串，其中可以包含Shell变量名、转义符等，一般用双引号括起来。缺省情况下echo不解释STRING中的转义符，加上-e 才可，缺省情况，echo 自动输出NEWLINE，加上-n 不输出换行符NEWLINE。
[root@windriver-machine shtest]# echo "\007you home is $HOME,you are connected on `tty`"
\007you home is /root,you are connected on /dev/pts/0
[root@windriver-machine shtest]# echo -e "\007you home is $HOME,you are connected on `tty`"
you home is /root,you are connected on /dev/pts/0
[root@windriver-machine shtest]# echo Hello world
Hello world
[root@windriver-machine shtest]# echo "Hello world"
Hello world
[root@windriver-machine shtest]# w
22:36:57 up 87 days, 23:16, 1 user, load average: 0.00, 0.00, 0.00
USER TTY FROM LOGIN@ IDLE JCPU PCPU WHAT
windrive pts/0 :2.0 Sat19 1.00s 0.28s 6.56s gnome-terminal
[root@windriver-machine shtest]# echo -e "Here is a tab\there are two tabs\t\tOK"
Here is a tab here are two tabs OK
[root@windriver-machine shtest]# echo "\"/dev/rmt0\""
"/dev/rmt0"
[root@windriver-machine shtest]# echo "The log files have all been done" >myfile
[root@windriver-machine shtest]# cat myfile
The log files have all been done
[root@windriver-machine shtest]#
【2】read 可以使用read语句从键盘或者文件中的某一行文本中读入信息，并将其赋给一个变量。
[root@windriver-machine shtest]# read -p "How old r u" age
How old r u32
[root@windriver-machine shtest]# echo $age
32
[root@windriver-machine shtest]# read -p "some words?" -a words
some words?I am a boy
[root@windriver-machine shtest]# echo ${word[*]}
[root@windriver-machine shtest]# echo ${words[*]}
I am a boy
[root@windriver-machine shtest]# read -p "Passowrd:" -s passwd
Passowrd:[root@windriver-machine shtest]# echo $passwd
teetesetbpadasdf
[root@windriver-machine shtest]# read -n
-bash: read: -n: option requires an argument
read: usage: read [-ers] [-u fd] [-t timeout] [-p prompt] [-a array] [-n nchars] [-d delim] [name ...]
[root@windriver-machine shtest]# read -t 5 auth
sdfasdfas
[root@windriver-machine shtest]# echo $auth
sdfasdfas
[root@windriver-machine shtest]# read -n 1 key
1[root@windriver-machine shtest]#
[root@windriver-machine shtest]# echo $key
1
[root@windriver-machine shtest]# read -dq -p "imput something end with q:" menu
imput something end with q:wobiq[root@windriver-machine shtest]# echo $menu
wobi
[root@windriver-machine shtest]# read -e myfile
hello
[root@windriver-machine shtest]# cat myfile
The log files have all been done
[root@windriver-machine shtest]# read -e myfile
ll
[root@windriver-machine shtest]# read -e myfile testfile
[root@windriver-machine shtest]#
【3】cat 显示文件内容，它显示内容与more和head命令不同，它不会分页显示，而是全显示，当然可以通过管道输出给more或head,less等。
[root@windriver-machine shtest]# cat myfile
The log files have all been done
[root@windriver-machine shtest]# read -e myfile
ll
[root@windriver-machine shtest]# read -e myfile testfile
[root@windriver-machine shtest]# ls
1234 1234.txt 123abc errors ex1.sh myfile newerr output testoutput testoutput2
[root@windriver-machine shtest]# cp myfile myfile1
[root@windriver-machine shtest]# cat myfile
The log files have all been done
[root@windriver-machine shtest]# cat myfile myfile1
The log files have all been done
The log files have all been done
[root@windriver-machine shtest]# cat
Hello world
Hello world
hello world
hello world
[root@windriver-machine shtest]# cat >myfile2
This is great
[root@windriver-machine shtest]# cat myfile2
This is great
[root@windriver-machine shtest]# cat -n /etc/passwd
1 root:x:0:0:root:/root:/bin/bash
2 bin:x:1:1:bin:/bin:/sbin/nologin
3 daemon:x:2:2:daemon:/sbin:/sbin/nologin
4 adm:x:3:4:adm:/var/adm:/sbin/nologin
5 lp:x:4:7:lp:/var/spool/lpd:/sbin/nologin
6 sync:x:5:0:sync:/sbin:/bin/sync
7 shutdown:x:6:0:shutdown:/sbin:/sbin/shutdown
8 halt:x:7:0:halt:/sbin:/sbin/halt
9 mail:x:8:12:mail:/var/spool/mail:/sbin/nologin
10 news:x:9:13:news:/etc/news:
[root@windriver-machine shtest]# cat -n myfile
1 The log files have all been done
[root@windriver-machine shtest]# cat -n myfile1 >myfile
myfile myfile1 myfile2
[root@windriver-machine shtest]# cat -n myfile1 >myfile3
[root@windriver-machine shtest]# cat myfile3
1 The log files have all been done
[root@windriver-machine shtest]# vi myfile1
[root@windriver-machine shtest]# cat -n myfile1
1 The log files have all been done
2
3
4 This is other line to do verify work
[root@windriver-machine shtest]# cat -b myfile1
1 The log files have all been done
2 This is other line to do verify work
[root@windriver-machine shtest]# cat myfile2
This is great
[root@windriver-machine shtest]# cat /dev/null >myfile2
[root@windriver-machine shtest]# cat myfile2
[root@windriver-machine shtest]#
【4】tee 会从标准输入设备读取数据，并将其内容输出到标准输出设备，同时保存成文件。 �Ca 附加到现有文件中。-i 忽略中断信号。
[root@windriver-machine shtest]# cat myfile1|tee myfile1.bak1 myfile1.bak2 myfile1.bak3
The log files have all been done
This is other line to do verify work
This is tab\tcontrol
[root@windriver-machine shtest]# ll
total 52
lrwxrwxrwx 1 root root 8 2011-08-06 22:07 1234 -> 1234.txt
-rw-r--r-- 1 root root 0 2011-08-07 01:43 1234.txt
drwsr-sr-x 2 windriver windriver 4096 2011-08-06 21:24 123abc
-rw-rw-r-- 2 windriver windriver 74 2011-08-06 22:11 errors
-rwxrwxr-x 1 windriver windriver 120 2011-08-06 01:44 ex1.sh
-rw-r--r-- 1 root root 33 2011-08-09 22:39 myfile
-rw-r--r-- 1 root root 94 2011-08-09 23:08 myfile1
-rw-r--r-- 1 root root 94 2011-08-09 23:12 myfile1.bak1
-rw-r--r-- 1 root root 94 2011-08-09 23:12 myfile1.bak2
-rw-r--r-- 1 root root 94 2011-08-09 23:12 myfile1.bak3
-rw-r--r-- 1 root root 0 2011-08-09 23:06 myfile2
-rw-r--r-- 1 root root 40 2011-08-09 23:05 myfile3
-rw-rw-r-- 2 windriver windriver 74 2011-08-06 22:11 newerr
-rw-rw-r-- 1 windriver windriver 1640 2011-08-06 19:13 output
-rw-r--r-- 1 root root 31 2011-08-07 02:14 testoutput
-rw-r--r-- 1 root root 169 2011-08-07 02:15 testoutput2
[root@windriver-machine shtest]#
【5】exec 系统环境都会被清除，重新启动一个shell，这个通常是用来执行一个脚本命令。
【6】|和> >> < << & 管道和重定向，这些前面已经说过，不在重复。
【7】date �Cs 设置系统时间 data �Cs 11/21/08 date �Cs 22:12:00，设置时间可以两次设置，也可一次性设置 date 112122202008.30 格式 月 日 时 分 年.秒 。虚拟终端时间与CMOS时间可能不一样，CMOS时间可以使用hwclock �Cshow 或clock --show来显示。
[windriver@windriver-machine shtest]$ date
Tue Aug 9 23:26:04 CST 2011
[windriver@windriver-machine shtest]$ date -s 08/08/2011
date: cannot set date: Operation not permitted
Mon Aug 8 00:00:00 CST 2011
[windriver@windriver-machine shtest]$ su - root
Password:
[root@windriver-machine ~]# date -s 08/08/2011
Mon Aug 8 00:00:00 CST 2011
[root@windriver-machine ~]#
[root@windriver-machine ~]#
[root@windriver-machine ~]# date -s 23:28:00
Mon Aug 8 23:28:00 CST 2011
[root@windriver-machine ~]#
[root@windriver-machine ~]#
[root@windriver-machine ~]# date
Mon Aug 8 23:28:03 CST 2011
[root@windriver-machine ~]# hwclock
Tue 09 Aug 2011 11:40:28 PM CST -0.009747 seconds
[root@windriver-machine ~]# hwclock --show
Tue 09 Aug 2011 11:42:25 PM CST -0.000300 seconds
[root@windriver-machine ~]# clock --show
Tue 09 Aug 2011 11:42:28 PM CST -0.000329 seconds
[root@windriver-machine ~]# date
Mon Aug 8 23:30:23 CST 2011
[root@windriver-machine ~]#
设置硬件时钟 hwclock �Cset -date=”09/17/2003 13:26:00”
同步系统时钟与硬件时钟 hwclock �C-hctosys
clock �C-hctosys 表示硬件时钟同步到系统时钟或者
hwclock �C-systohc 或clock �Csystohc 或者hwclock -w写入硬件时钟CMOS
[root@windriver-machine ~]# date
Mon Aug 8 23:30:23 CST 2011
[root@windriver-machine ~]# hwclock --hctosys
[root@windriver-machine ~]#
[root@windriver-machine ~]#
[root@windriver-machine ~]#
[root@windriver-machine ~]#
[root@windriver-machine ~]# date
Tue Aug 9 23:45:47 CST 2011
[root@windriver-machine ~]# date 080923312011.30
Tue Aug 9 23:31:30 CST 2011
[root@windriver-machine ~]#
[root@windriver-machine ~]#
[root@windriver-machine ~]# clock --show
Tue 09 Aug 2011 11:46:54 PM CST -0.000331 seconds
[root@windriver-machine ~]# hwclock -w
[root@windriver-machine ~]# hwclock --show
Tue 09 Aug 2011 11:32:01 PM CST -0.000321 seconds
[root@windriver-machine ~]# date
Tue Aug 9 23:32:08 CST 2011
[root@windriver-machine ~]#
【8】&&和|| 将多个shell命令同时执行。&&表明前一个命令执行成功，而||通常意味着前一个命令执行失败。
[root@windriver-machine shtest]# sort myfile1 >myfile4 && echo "if you are seeing this, then sort is ok"
if you are seeing this, then sort is ok
[root@windriver-machine shtest]# cp /etc/passwd passwd.bak && echo "if you are seeing this,the cp is ok"
if you are seeing this,the cp is ok
[root@windriver-machine shtest]# cp /etc/passwd passwd.bak || echo "if you are seeing this,the cp is ok"
cp: overwrite `passwd.bak'? y
[root@windriver-machine shtest]#