linux命令之文本查看

vi掌握练习：

英文文档，相同的单词复制粘贴光标移动编辑等操作；

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cat：显示文件所有内容，小文件查看时使用。

缺点：文件大时不方便查看，文件很大时，会抢占系统资源，会出现命令崩溃。

[zyj@localhost ~]$ cat /etc/passwd
root:x:::root:/root:/bin/bash
bin:x:::bin:/bin:/sbin/nologin
daemon:x:::daemon:/sbin:/sbin/nologin
adm:x:::adm:/var/adm:/sbin/nologin
lp:x:::lp:/var/spool/lpd:/sbin/nologin
sync:x:::sync:/sbin:/bin/sync
shutdown:x:::shutdown:/sbin:/sbin/shutdown
halt:x:::halt:/sbin:/sbin/halt
mail:x:::mail:/var/spool/mail:/sbin/nologin
uucp:x:::uucp:/var/spool/uucp:/sbin/nologin
operator:x:::operator:/root:/sbin/nologin
games:x:::games:/usr/games:/sbin/nologin
gopher:x:::gopher:/var/gopher:/sbin/nologin
ftp:x:::FTP User:/var/ftp:/sbin/nologin
nobody:x:::Nobody:/:/sbin/nologin
dbus:x:::System message bus:/:/sbin/nologin
usbmuxd:x:::usbmuxd user:/:/sbin/nologin
rtkit:x:::RealtimeKit:/proc:/sbin/nologin
avahi-autoipd:x:::Avahi IPv4LL Stack:/var/lib/avahi-autoipd:/sbin/nologin
vcsa:x:::virtual console memory owner:/dev:/sbin/nologin
abrt:x::::/etc/abrt:/sbin/nologin
haldaemon:x:::HAL daemon:/:/sbin/nologin
ntp:x::::/etc/ntp:/sbin/nologin
apache:x:::Apache:/var/www:/sbin/nologin
saslauth:x:::Saslauthd user:/var/empty/saslauth:/sbin/nologin
postfix:x::::/var/spool/postfix:/sbin/nologin
gdm:x::::/var/lib/gdm:/sbin/nologin
pulse:x:::PulseAudio System Daemon:/var/run/pulse:/sbin/nologin
sshd:x:::Privilege-separated SSH:/var/empty/sshd:/sbin/nologin
tcpdump:x::::/:/sbin/nologin
zyj:x::: python_full:/home/zyj:/bin/bash

tac：倒序读文件

[zyj@localhost ~]$ tac /etc/passwd
zyj:x::: python_full:/home/zyj:/bin/bash
tcpdump:x::::/:/sbin/nologin
sshd:x:::Privilege-separated SSH:/var/empty/sshd:/sbin/nologin
pulse:x:::PulseAudio System Daemon:/var/run/pulse:/sbin/nologin
gdm:x::::/var/lib/gdm:/sbin/nologin
postfix:x::::/var/spool/postfix:/sbin/nologin
saslauth:x:::Saslauthd user:/var/empty/saslauth:/sbin/nologin
apache:x:::Apache:/var/www:/sbin/nologin
ntp:x::::/etc/ntp:/sbin/nologin
haldaemon:x:::HAL daemon:/:/sbin/nologin
abrt:x::::/etc/abrt:/sbin/nologin
vcsa:x:::virtual console memory owner:/dev:/sbin/nologin
avahi-autoipd:x:::Avahi IPv4LL Stack:/var/lib/avahi-autoipd:/sbin/nologin
rtkit:x:::RealtimeKit:/proc:/sbin/nologin
usbmuxd:x:::usbmuxd user:/:/sbin/nologin
dbus:x:::System message bus:/:/sbin/nologin
nobody:x:::Nobody:/:/sbin/nologin
ftp:x:::FTP User:/var/ftp:/sbin/nologin
gopher:x:::gopher:/var/gopher:/sbin/nologin
games:x:::games:/usr/games:/sbin/nologin
operator:x:::operator:/root:/sbin/nologin
uucp:x:::uucp:/var/spool/uucp:/sbin/nologin
mail:x:::mail:/var/spool/mail:/sbin/nologin
halt:x:::halt:/sbin:/sbin/halt
shutdown:x:::shutdown:/sbin:/sbin/shutdown
sync:x:::sync:/sbin:/bin/sync
lp:x:::lp:/var/spool/lpd:/sbin/nologin
adm:x:::adm:/var/adm:/sbin/nologin
daemon:x:::daemon:/sbin:/sbin/nologin
bin:x:::bin:/bin:/sbin/nologin
root:x:::root:/root:/bin/bash
[zyj@localhost ~]$

more：显示一个版面，按空格继续显示，并显示百分比，按q退出查看。

less：一行一行显示，和more差不多

[zyj@localhost ~]$ more /etc/profile
# /etc/profile

# System wide environment and startup programs, for login setup
# Functions and aliases go in /etc/bashrc

# It's NOT a good idea to change this file unless you know what you
# are doing. It's much better to create a custom.sh shell script in
# /etc/profile.d/ to make custom changes to your environment, as this
# will prevent the need for merging in future updates.

pathmunge () {
    case ":${PATH}:" in
        *:"$1":*)
            ;;
        *)
            if [ "$2" = "after" ] ; then
                PATH=$PATH:$
            else
                PATH=$:$PATH
            fi
    esac
}

if [ -x /usr/bin/id ]; then
    if [ -z "$EUID" ]; then
        # ksh workaround
        EUID=`/usr/bin/id -u`
        UID=`/usr/bin/id -ru`
    fi
    USER="`/usr/bin/id -un`"
    LOGNAME=$USER
    MAIL="/var/spool/mail/$USER"
fi

# Path manipulation
--More--(%)

 tail：查看文件的末尾，默认显示尾部10行，查看新增日志文件。可以通过-加数字选择查看尾部具体的行数；

[zyj@localhost ~]$ tail /etc/profile
        if [ "${-#*i}" != "$-" ]; then
            . "$i"
        else
            . "$i" >/dev/null >&
        fi
    fi
done

unset i
unset -f pathmunge
[zyj@localhost ~]$ 

[zyj@localhost ~]$ tail-f  /etc/profile   //查看实时日志，新增的日志追加显示出来。
-bash: tail-f: command not found
[zyj@localhost ~]$ tail -f  /etc/profile
        if [ "${-#*i}" != "$-" ]; then
            . "$i"
        else
            . "$i" >/dev/null >&
        fi
    fi
done

unset i
unset -f pathmunge

 [zyj@localhost ~]$ tail -  /etc/profile    //显示尾部后5行
     fi
 done

 unset i
 unset -f pathmunge
 [zyj@localhost ~]$ 

head：默认显示前10行，可以通过-加数字选择查看前面具体的行数；

[zyj@localhost ~]$ head /etc/profile
# /etc/profile

# System wide environment and startup programs, for login setup
# Functions and aliases go in /etc/bashrc

# It's NOT a good idea to change this file unless you know what you
# are doing. It's much better to create a custom.sh shell script in
# /etc/profile.d/ to make custom changes to your environment, as this
# will prevent the need for merging in future updates.

[zyj@localhost ~]$ 

 [zyj@localhost ~]$ head - /etc/profile  //显示前5行
 # /etc/profile

 # System wide environment and startup programs, for login setup
 # Functions and aliases go in /etc/bashrc

 [zyj@localhost ~]$ 

查找文件命令find

[zyj@localhost home]$ find h* //在当前目录下查找以h开头的文件
hello.txt
[zyj@localhost home]$ find /etc/pass* //etc目录下查找以pass开头的文件
/etc/passwd
/etc/passwd-
/etc/passwd.OLD
[zyj@localhost ~]$ find /etc/pass* -print //etc目录下查找以pass开头的文件，并显示出来
/etc/passwd
/etc/passwd-
/etc/passwd.OLD

在文件内容中查找关键字grep

[zyj@localhost ~]$ grep 'root' /etc/passwd //查找passwd中包含root的内容
root:x:::root:/root:/bin/bash
operator:x:::operator:/root:/sbin/nologin
[zyj@localhost ~]$ grep '^root' /etc/passwd //以root作为行的开始的内容
root:x:::root:/root:/bin/bash
[zyj@localhost ~]$ grep 'bash$' /etc/passwd   //查找以bash结尾的内容
root:x:::root:/root:/bin/bash
zyj:x::: python_full:/home/zyj:/bin/bash

 管道：把管道左边的命令执行的结果传给右边的命令；命令1|命令2|命令3......

[zyj@localhost ~]$ head - /etc/profile
# /etc/profile

# System wide environment and startup programs, for login setup
# Functions and aliases go in /etc/bashrc

# It's NOT a good idea to change this file unless you know what you
# are doing. It's much better to create a custom.sh shell script in
# /etc/profile.d/ to make custom changes to your environment, as this
# will prevent the need for merging in future updates.
[zyj@localhost ~]$ head - /etc/profile | tail - //前9行的倒数第一行即第9行；
# will prevent the need for merging in future updates.

[zyj@localhost ~]$ ls -al | more //显示多的时候可以通过管道后配置more、less使用
total
drwx------.  zyj  zyj   Apr  : .
drwxr-xr-x.   root root  Apr  : ..
-rw-------.   zyj  zyj   Apr  : .ICEauthority
-rw-------.   zyj  zyj   Apr  : .bash_history
-rw-r--r--.   zyj  zyj     Mar    .bash_logout
-rw-r--r--.   zyj  zyj    Mar    .bash_profile
-rw-r--r--.   zyj  zyj    Apr  : .bashrc
drwxr-xr-x.   zyj  zyj   Apr  : .cache
drwxr-xr-x.   zyj  zyj   Apr  : .config
drwx------.   zyj  zyj   Apr  : .dbus
-rw-r--r--.   zyj  zyj     Apr  : .dmrc
-rw-------.   zyj  zyj     Apr  : .esd_auth
drwxr-xr-x.   zyj  zyj   Apr  : .fontconfig
drwx------.   zyj  zyj   Apr  : .gconf
drwxr-xr-x.   zyj  zyj   Apr  : .gnome2
drwxrwxr-x.   zyj  zyj   Apr  : .gnote
drwx------.   zyj  zyj   Apr  : .gnupg
-rw-rw-r--.   zyj  zyj    Apr  : .gtk-bookmarks
drwx------.   zyj  zyj   Apr  : .gvfs
-rw-------.   zyj  zyj     Apr  : .lesshst
drwxr-xr-x.   zyj  zyj   Apr  : .local
drwxr-xr-x.   zyj  zyj   Apr  : .mozilla
drwxr-xr-x.   zyj  zyj   Apr  : .nautilus
drwx------.   zyj  zyj   Apr  : .pulse
-rw-------.   zyj  zyj    Apr  : .pulse-cookie
drwx------.   zyj  zyj   Apr  : .ssh
-rw-------.   zyj  zyj   Apr  : .viminfo
-rw-rw-r--.   zyj  zyj     Apr  : .vimrc
-rw-------.   zyj  zyj   Apr  : .xsession-errors
-rw-------.   zyj  zyj   Apr  : .xsession-errors.old
drwxr-xr-x.   zyj  zyj   Apr  : Desktop
drwxr-xr-x.   zyj  zyj   Apr  : Documents
drwxr-xr-x.   zyj  zyj   Apr  : Downloads
drwxr-xr-x.   zyj  zyj   Apr  : Music
drwxr-xr-x.   zyj  zyj   Apr  : Pictures
--more

[zyj@localhost ~]$ ps aux | grep tty //查找包含tty的进程
root         0.0  0.0       tty2     Ss+  :   : /sbin/mingetty /dev/tty2
root         0.0  0.0       tty3     Ss+  :   : /sbin/mingetty /dev/tty3
root         0.0  0.0       tty4     Ss+  :   : /sbin/mingetty /dev/tty4
root         0.0  0.0       tty5     Ss+  :   : /sbin/mingetty /dev/tty5
root         0.0  0.0       tty6     Ss+  :   : /sbin/mingetty /dev/tty6
root         0.1  2.4   tty1     Ss+  :   : /usr/bin/Xorg : -br -verbose -audit  -auth /var/run/gdm/auth-for-gdm-cxJWaZ/database -nolisten tcp vt1
zyj          0.0  0.0     pts/    S+   :   : grep tty
[zyj@localhost ~]$
[zyj@localhost ~]$ ps aux | grep tty | grep tty2 //命令1|命令2
root  0.0 0.0   tty2 Ss+ : : /sbin/mingetty /dev/tty2
zyj  0.0 0.0   pts/ S+ : : grep tty2

[zyj@localhost ~]$ ls /etc/ | grep passwd //在etc下的文件中查找有passwd的内容；
passwd
passwd-
passwd.OLD
[zyj@localhost ~]$ find /etc/pass*
/etc/passwd
/etc/passwd-
/etc/passwd.OLD

文本处理：

cut：切文件,常用-d 和-f 选项。

[zyj@localhost home]$ echo "1,2,3,4,5" | cut -d',' -f1 //以逗号为分隔符分割，并显示分割后的第一个字符串。

[zyj@localhost home]$ echo "1,12,23,44,55" | cut -d',' -f1,//以逗号为分隔符分割，并显示分割后的第一个和第4个字符串。
,
[zyj@localhost home]$ echo "1,12,23,44,55" | cut -d',' -f1-//以逗号为分隔符分割，并显示分割后的第一个和第5个字符串
,,,,
[zyj@localhost home]$ tail - /etc/passwd | cut -d":" -f1
zyj

sort：排序

[zyj@localhost ~]$ du /home/zyj/ | grep mozilla | sort -n //升序排序
       /home/zyj/.mozilla/extensions
       /home/zyj/.mozilla/plugins
      /home/zyj/.mozilla
[zyj@localhost ~]$ du /home/zyj/ | grep mozilla | sort -n -r //降序排序
      /home/zyj/.mozilla
       /home/zyj/.mozilla/plugins
       /home/zyj/.mozilla/extensions

[zyj@localhost home]$ sort /etc/passwd //字符串排序
abrt:x::::/etc/abrt:/sbin/nologin
adm:x:::adm:/var/adm:/sbin/nologin
apache:x:::Apache:/var/www:/sbin/nologin
avahi-autoipd:x:::Avahi IPv4LL Stack:/var/lib/avahi-autoipd:/sbin/nologin
bin:x:::bin:/bin:/sbin/nologin
daemon:x:::daemon:/sbin:/sbin/nologin
dbus:x:::System message bus:/:/sbin/nologin
ftp:x:::FTP User:/var/ftp:/sbin/nologin
games:x:::games:/usr/games:/sbin/nologin
gdm:x::::/var/lib/gdm:/sbin/nologin
gopher:x:::gopher:/var/gopher:/sbin/nologin
haldaemon:x:::HAL daemon:/:/sbin/nologin
halt:x:::halt:/sbin:/sbin/halt
lp:x:::lp:/var/spool/lpd:/sbin/nologin
mail:x:::mail:/var/spool/mail:/sbin/nologin
nobody:x:::Nobody:/:/sbin/nologin
ntp:x::::/etc/ntp:/sbin/nologin
operator:x:::operator:/root:/sbin/nologin
postfix:x::::/var/spool/postfix:/sbin/nologin
pulse:x:::PulseAudio System Daemon:/var/run/pulse:/sbin/nologin
root:x:::root:/root:/bin/bash
rtkit:x:::RealtimeKit:/proc:/sbin/nologin
saslauth:x:::Saslauthd user:/var/empty/saslauth:/sbin/nologin
shutdown:x:::shutdown:/sbin:/sbin/shutdown
sshd:x:::Privilege-separated SSH:/var/empty/sshd:/sbin/nologin
sync:x:::sync:/sbin:/bin/sync
tcpdump:x::::/:/sbin/nologin
usbmuxd:x:::usbmuxd user:/:/sbin/nologin
uucp:x:::uucp:/var/spool/uucp:/sbin/nologin
vcsa:x:::virtual console memory owner:/dev:/sbin/nologin
zyj:x::: python_full:/home/zyj:/bin/bash

linux引号：

1、双引号“” 弱引号，会解析特殊符号，如$

2、单引号‘’ 强引号，引号引起的地方为字符串

3、反引号·：命令替换。

[zyj@localhost ~]$ a=
[zyj@localhost ~]$ echo "$a"

[zyj@localhost ~]$ echo '$a'
$a
[zyj@localhost ~]$ whoami
zyj
[zyj@localhost ~]$ echo "whoami"
whoami
[zyj@localhost ~]$ echo 'whoami'
whoami
[zyj@localhost ~]$ echo `whoami` //数字1旁边的按键
zyj
[zyj@localhost ~]$