jpuyy的网志

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  • ethtool检测和管理网卡

    ethtool是检测和管理网卡设置的工具

    ethtool的实用之处之一是可以查看网线是否插到网卡上

    如果有显示信息Link detected: yes，则说明在链路状态，表明插上网线并且在通讯

    #ethtool em1

Settings for em1:
Supported ports: [ TP ]
Supported link modes: 10baseT/Half 10baseT/Full
100baseT/Half 100baseT/Full
1000baseT/Full
Supports auto-negotiation: Yes
Advertised link modes: 10baseT/Half 10baseT/Full
100baseT/Half 100baseT/Full
1000baseT/Full
Advertised pause frame use: No
Advertised auto-negotiation: Yes
Speed: 1000Mb/s
Duplex: Full
Port: Twisted Pair
PHYAD: 1
Transceiver: internal
Auto-negotiation: on
MDI-X: Unknown
Supports Wake-on: g
Wake-on: d
Link detected: yes

    如果显示Link detected: no，表明插上网线但没有链路

    #ethtool em2
Settings for em2:
Supported ports: [ TP ]
Supported link modes: 10baseT/Half 10baseT/Full
100baseT/Half 100baseT/Full
1000baseT/Full
Supports auto-negotiation: Yes
Advertised link modes: 10baseT/Half 10baseT/Full
100baseT/Half 100baseT/Full
1000baseT/Full
Advertised pause frame use: No
Advertised auto-negotiation: Yes
Speed: Unknown!
Duplex: Half
Port: Twisted Pair
PHYAD: 1
Transceiver: internal
Auto-negotiation: on
MDI-X: Unknown
Supports Wake-on: g
Wake-on: d
Link detected: no

    如果找不到设备，则没有网线插入

    #ethtool em3
Settings for em3:
Cannot get device settings: No such device
Cannot get wake-on-lan settings: No such device
Cannot get message level: No such device
Cannot get link status: No such device
No data available

    查看 veth　设备对的 peer　另一端

    ethtool -S veth1

  • smbclient的使用

    使用smbclient可以方便的连接上windows共享目录或samba

    smbclient //192.168.11.32/test -U administrator 回车输入密码
Enter administrator's password: 
Domain=[COMPUTER] OS=[Windows 5.1] Server=[Windows 2000 LAN Manager]
smb: \>

    常用的命令有ls显示，cd切换目录，del删除，put上传，get下载等。

  • chattr lsattr命令

    chattr与lsattr可以修改文件属性，是比chmod, chown的属性更底层的属性。

    chattr可以结合 -减  +增  = 指定 属性

    查看属性，默认只有一个e属性

    #lsattr /etc/hosts
-------------e- /etc/hosts

    添加i属性，则这个文件将不能修改，删除，重命名，追加，也不能创建硬链接。root也只能在回收这个属性值之后才能正常使用。

    # chattr +i /etc/hosts
# lsattr /etc/hosts
----i--------e- /etc/hosts
rm /etc/hosts会出现Operation not permitted

    添加a属性，使文件只能被追加，不能被删除，常用于日志文件，比如说在logrotate的时候对日志文件先-a，然后再+a。如nginx的logrotate

    # This configuration is from jpuyy 2013-12-16
 /web/nginx/logs/access.log {
 weekly
 rotate 5
 compress
 sharedscripts
 prerotate
 /usr/bin/chattr -a /web/nginx/logs/access.log
 endscript
 sharedscripts
 postrotate
 /usr/bin/killall -HUP nginx
 /usr/bin/chattr +a /web/nginx/logs/access.log
 endscript
 }

    chattr -R 递规更改属性

  • mysql between用法

    mysql中的between and用于将一定范围内的数据取出，包含了边界值， 查看ID号在20至50之间的用户，包含20和50：

    SELECT * FROM user WHERE uid BETWEEN 20 AND 50

    还可以查看在字符范围内的，应该是按ASCII码排序

    SELECT * FROM user WHERE name BETWEEN a AND e;

    between and 比较时间，可以是从1970-01-01 00:00:00的秒数，如1387210733，可以是date格式，也可以是datetime格式。如

    SELECT * FROM user WHERE rtime BETWEEN '2010-08-10' AND '2013-12-10';

  • dpkg使用方法

    查看已经安装的软件包

    dpkg --get-selections

    查看npm包都包含哪些文件

    dpkg -L npm

    查看npm的详情(status)

    dpkg -s npm

     

  • sql查询结果保存与文件读取

    将查询结果保存到文件里， 注意 如果已经存在同名文件，则不会创建。

    SELECT…INTO OUTFILE

    例子：

    select name,ctfid,birthday,mobile,tel,email from info where ctfid like '130000%' into outfile '/tmp/fuping-of-rujia';

    同时可以指定分隔符等

    SELECT a,b,a+b INTO OUTFILE '/tmp/result.text'

FIELDS TERMINATED BY ',' OPTIONALLY ENCLOSED BY '"'

LINES TERMINATED BY '\n'

FROM test_table;

    从文件读取的语法为

    LOAD DATA INFILE

    同样可以指定分隔符等，例如从csv文件导入：

    load data local infile '1-200W.csv' into table `info` fields terminated by ',' lines terminated by '\n';