Linux

Solve the problem that up may access a non-existent data structure (release the semaphore after down): see in depth 3, page216-217. 1. completion () corresponds to up () 2. wait_for_completion () corresponds to down   Unlike semaphores,

4.2 lastcomm: displays information about commands used previously. Role: accton is used to START process records. In this way, all commands are recorded in a specified file, and lastcomm is used to view the file for system management. Usage:

4.5 ATQ: display the command queue to be executed after the AT command is currently used Purpose: run the ATQ command to query the SET command sequence. When a user is a Super User, list all jobs. Usage: ATQ [-V] [-Q queue] The main options are as

4.12 crontab: set the timer Purpose: The crontab command is used to install, delete, or list the task tables used to drive cron background processes. Then, the configuration is executed by the cron daemon at the specified time. Usage: crontab [-u

The signal is asynchronous and occurs anywhere in the program. As a result, the normal execution path of the program is broken and the signal processing function is executed. Generally The process is executing a system call, so the signal will not

Put the Ubuntu IP address in/etc/Network/interfaces, and put the DNS settings in/etc/resolv. conf.   Set static IP addresses 1. Backup/etc/Network/interfaces: sudo CP/etc/Network/interfaces. Backup 2. edit/etc/Network/interfaces: sudo

Top: Display Processes Purpose: The top command is used to display the current process status of the system. Usage: Top [Option] The main options are as follows. --B: Use the batch processing mode. --C: displays the program and complete information

Fuser: process is represented by a file or a set of interfaces. Purpose: The Fuser command represents a process using a file or a set of interfaces. Usage: fuser [-A |-S |-C] [-4 |-6] [-n Space] [-K [-I] [-signal] [-muvf] Name... Or Fuser-l Or Fuser-

PS: TCPDUMP is a tool used to intercept network groups and output group content. It is simply a packet capture tool. Tcpdump is the preferred tool for Network Analysis and troubleshooting in Linux based on its powerful functions and flexible

For Linux system administrators, monitoring the system is very important. There are many Linux system monitoring tools, and top is the most commonly used one. It can dynamically observe the status of system processes, so that the system

The basic IT "Basic Skills" that testers need to master include some basic knowledge about the operating system. Because windows is familiar with, they should focus on learning Linux, linux is the operating system used by the background servers of

  The friendly mini2440 is used on the board. At first, according to the instruction manual provided by the CD, the pictures are as follows ..... the reason is that you have not understood the relationship between makefile and kconfig in each layer

1. Use ARP and ARP-a to view the current ARP cache list.[Root @ FTP] # ARPAddress hwtype hwaddress flags mask iface192.168.0.145 ether 00: 13: 20: E9: 11: 04 C eth0192.168.0.1 ether 00: 02: 03: 18: 08: 00 C eth0 Note:Address: IP address of the

AliasAlias the command.Eg:Alias LL = 'LS-al' The use of alias on the terminal is only available this time. The definition of Alias is usually placed in. bashrc under the user's home directory, using vi ~ /. Bashrc check whether there are several

We know that the cat command can be used to view text content.   Cat ***.     But sometimes there is such a requirement that a program sub-branch results in n log files, hundreds of. We need to find rows containing some keywords in these n log

Address: http://www.mylouge.com/2011/07/2082.html Ubuntu is a lightweight derivative version of ubuntu, so many of its software is not installed by default, which includes Ubuntu one and Ubuntu software centers, however, these two software are the

Summarized knowledge points include: 1. in VMware, Linux uses minicom to communicate with the Development Board; 2. Mount the Linux system on the PC to the NFS file system on the target Development Board; 3. Modify the permission of an object; 4.

1. Test EnvironmentServer: RedHat Linux 3.4.3-9. EL4 (kernel version 2.6.9-5.el), tomcat5.5.20, Sun JDK 1.5.0 _ 09, jprofiler 4.3.2 For Linux (installation package: jprofiler_linux_4_3_2.sh)Client: Windows XP, jprofiler 4.3.2 For Windows

Http://www.cnblogs.com/taobataoma/archive/2007/08/30/875743.html Sighup1. Terminal A is suspended or the control process is terminated.SIGINT 2 a keyboard interruption (for example, the Break Key is pressed)The exit key of the sigquit 3 C keyboard

I am using the Ubuntu Linux operating system. The phenomenon is that when QT creator starts debugging, it prompts "you can't do that without a process to debug ". This problem has plagued me for a long time. Most of the answers on the Internet are