1. Cat command:function:1) Displays the entire file.Demo Sample: $ cat FileName2) Connect the file string to the basic output, such as merging several files into one file or output to the screen.Demo Sample: $ cat file1 file2 > fileDescription: Connect the file string to the basic output (screen or add > FileName to a file)Cat references are explained in detail:-N or –number numbering of all output lines starting from 1-B or –number-nonblank and-n are
From: http://blog.cfan.com.cn
Log File, which records every detail of running Windows systems and various services, plays a very important role in enhancing the stability and security of Windows. However, many users do not pay attention to its protection. Some "uninvited users" can easily clear log files, posing a serious security risk to the system.
1. What is a
How Linux uses commands to view a few lines of a log file (middle or last lines)How Linux displays a few lines of a file (in the middle of a few lines)"One" starts at line No. 3000 and displays 1000 rows. The 3000~3999 line is displayedCat FileName | Tail-n +3000 | Head-n 1000"Two" displays 1000 rows to 3000 rowsCat filename| Head-n 3000 | Tail-n +1000* Note the order of the two methodsDecomposition:Tail-n
::socket_pub); $publisher->bind ("tcp://*:5555"); Sleep (1); $publisher->send (' hello '); Echo ' Sent Hello ';? >Third, the client code1, a total of two files, the client is can directly run EXE file, MyLog is. NET source code, edited with VS2010. Open the client file and just click Mylog.exe to open the gadget. 2. Clrzmq.dll is a ZMQ auxiliary DLL file in. NET and needs to be introduced into the source code.3, in the client do ZM
Oracle
Experience Summary:
The online logs are divided into current and non current online logs, and the corruption of the non-current online log is relatively simple, and the problem can be resolved by the clear command.
Corrupt non-current online log:
1, start the database, encountered ORA-00312 or ORA-00313 error, such as:
Ora-00313:open failed for members of log
Troubleshooting of default temporary tablespace and redo log files in Oracle
Problem: I want to synchronize Oracle Data to MySQL now. the ETL tool is used because the data volume is large and temporary tablespace is used for subqueries, resulting in the original temporary tablespace, insufficient space. Based on the error message, I directly thought of adding a temporary file to the temporary tablespace. I
1. Try to use VMware View Client 5.0 to select the PCoIP protocol to log on to the allocated virtual desktop for a period of time, the system will automatically shut down, and when you log on again, the system will prompt that the desktop is busy and you cannot successfully log on to the allocated virtual desktop;
2.
Tags: Exit message content init content interactive Information Form AST username[Last]LastView User Login Record-N Displays only the most recent Related configuration Files/var/log/wtmp[LASTB]LastbLog login information for user error-N Show only recent Related configuration Files/var/log/btmp[Lastlog]LastlogShows the
single file based on each table, then set Innodb_file_per_table to ON, which will create a tablespace for each table, but even so, shared tablespaces are essential, Because the data dictionary needs to be put inside, it's just not going to take up so much space.
The following figure shows how InnoDB is stored:
The following storage files are mainly available in the above illustration:
1 table structure definition file (. frm): MySQL each table,
. It only keeps the user records online at the time and does not keep permanent records for the user. Programs in the system that need to query the current user status, such as WHO, W, users, and finger, need to access this file. This log file does not contain all accurate information, because some unexpected errors will terminate the user logon session, and the system does not update the utmp record in time, therefore, the
[Linux Notes] how to use the logrotate tool to automatically split the log files in the scroll, linuxlogrotate
In many real projects, applications continuously write logs. If the program code does not call a logstore that supports automatic splitting (such as by filesize or date, then the log file will soon grow to the G level. It is inconvenient to operate large
Experience Summary:
The online logs are divided into current and non current online logs, and the corruption of the non-current online log is relatively simple, and the problem can be resolved by the clear command.
Corrupt non-current online log:1, start the database, encountered ORA-00312 or ORA-00313 error, such as:Ora-00313:open failed for members of log Group
Native to Ubuntu system, Local System character encoding is:Echo $LANGZh_cn. UTF-8The character encoding for the remote server (121.199.42.27) is:Zh_cn. GB18030After logging on to the server via SSH, check the Catalina.out log in Tomcat and find that Chinese is garbled.The following are the solutions:
VI catalina.out: Set Termencoding=utf-8
Tail,more and other viewing files garbled way to solve
Use the dwarfdump command and the dsym file to link binary image to view the crash log... first, you need to package the dsym file, and then enter the command in the terminal: 1 $ dwarfdump -- lookup = ADDRESS -- arch = ARCH {MyApp. app. dsym} 001NAME002 dwarfdump -- dump DWARF debug information.003 004SYNOPSIS005 dwarfdump [options] file1 file2... 006 007DESCRIPTION008 For each operand that names a mach-o
Original: HTTP://SEANLOOK.COM/2014/08/23/LINUX-LOGWATCH-USAGE/1. IntroducedWhen maintaining a Linux server, it is often necessary to review the logs of various services in the system to check the server's operational status. such as login history, mail, software installation and other logs. It is very inconvenient for the system administrator to check each one, and most of the time, this is a passive check, that is, only when the system is found to be running abnormally, would you want to
file. After the SQL Server restarts, it will view the latest mark point in the log and erase the transaction record after the mark point, because these transaction records do not actually write data in the cache into the data file. This prevents the interrupted transactions from modifying data files.
Maintain transaction logs
Because many people often forget th
Modify the size of Oracle redo log files
Modify the size of Oracle redo log files
1. Create 3 new log groups
SQL> ALTER DATABASE ADD LOGFILE GROUP 4 ('/u01/app/oracle/oradata/orcl/redo06.log') SIZE 500 M;
SQL> ALTER DATABASE ADD L
The program is divided into the site side and the center side (equivalent to a proxy).This small function is mainly to solve, the program often let us go to drag the log, especially annoying. So make a small program. So that the program can go to the online view.One problem is that the game server cannot be exposed, and there is a public network bandwidth that cannot occupy the business machine.This small program is mainly the central side (proxy) to
Use logwatch to monitor log files in Linux
Linux operating systems and many applications create special files to record their running events. These files are often called "logs ". These system logs or specific application log files
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