linux scripting basics

] ~]# which --skip-alias ls/bin/lsThe whatis:whatis command displays the header line of the manual section. You can then issue the man command to get additional information[[email protected] ~]# Whatis CDCD (1p)-Change the working directoryCD [Builtins] (1)-bash built-in commands, see Bash (1)[Email protected] ~]# Whatis mkdirmkdir (1)-Make directoriesmkdir (1p)-Make directoriesmkdir (2)-Create a directorymkdir (3p)-Make a directory[Email protected] ~]# Whatis useraddUseradd (8)-Create a new use

is an executable file that runs on a 64-bit platform and uses a dynamic link file (Shared library).7. Edit the fileEditing files under Linux usually we use a dedicated command-line editor like (Emacs,vim,nano), because the content of the editor involved in Linux is more and more important, so we have a separate basic course specifically about one of these editors (VIM). here is a strong hope that you are l

than memory. For example, if the CPU is able to make 10 requests to memory in a second, memory can only return 11 requests. What about this time? The CPU resources are not wasted. So this time we have the CPU's first-level cache and the level two cache. Buffering in the CPU and memory. The CPU cache is much faster than the memory block but slower than the CPU. But this has greatly alleviated the problem of too slow memory. If we want the CPU cache to work, we need our local rules. Local laws ha

Basics of Linux Learning 1, what is Linux? To be exact, the Linux kernel (the core program of the system), whose kernel copyright belongs to Linus Torvalds, is issued under the GPL (GNU general public License) Copyright Agreement, and anyone can copy (copy) and modify ( Change), package distribution (distribute), sales

"graphic shells."The Shell under the Unix/linux operating system is both an interface for user interaction and a scripting language for control systems. This, of course, differs from the command line under Windows, although it also provides a very simple control statement. Under the Windows operating system, some users may never use the shell directly, but under the UNIX family operating system, the shell

edit the boot setting system file, and load Linux through ext2 or ext3 file system. Kernel (Grub can identify almost all Linux supported file systems with different file system drivers, so many file systems can be used to format the sector of the kernel file, not limited to the Ext file system).The logo and mascot of Linux is a penguin named Tux, the origin of w

user's account informationID [Options] USERNAME-U Print User ID-G Print the base group ID-G print ID for all groups-N Prints the name instead of the ID5.finger USERNAMEView user's account information6. Password Management passwdpasswd [USERNAME]--stdin Password Change password read from standard inputecho 123456 | passwd Joedut--stdin-L Lock Account-U Unlock Account-D: Remove user password-N Minimum Password usage period-X Password maximum age7. Create a groupGroupadd-G GID-R: Added as System g

jiffies and Hz, before it is no clock event.II: The concept of jiffies and HzThe size of the Hz on the arm system is generally 100, indicating that there are 100 beats in 1s, jiffies represents the total number of Beats since the start of the system, Jiffies is generally unsigned long type, so it may overflow. For example: unsigned long jiffies; unsigned long timeout=jiffies+hz/2; the 0.5s of the future.Jiffies wrap-Around problem:[CPP]View Plaincopy 01.unsigned long jiffies; 02.u

the properties of a file that is under SELinux controlSetsebool-P Perpetual effectOpen Anonymous user uploadsAllow_ftpd_anon_write onAllow_ftpd_full_access onGetsebool-ARsylog:LOG: History logLevel:Syslog syslogd KLOGDFacility: A facility that classifies logs from a feature or program, and copies records of its logs by a specialized toolCENTOS6 RsyslogModLoad imudp Loading UDP protocol-: Indicates an asynchronous writeLog collection and analysis tools:LogstashAnalytics Tools HadoopHomework:Anal

Part1:python compiling1, directly in the terminal compile-----in Ubuntu Python is in the home folder, input python (Python2 compilation, want to Python3 direct input python3)The general recommended use is: Ipython32, use VI to create a file, python+ file name compilation. You can use VI to create a file or use the sublimePart 2: Minor problems encountered1, the use of VI display has the existence of exchange files, prompt to do not compile, and give some options, directly select Delete canPython

interface under the same Unix/linux GNOME and KDE are sometimes referred to as "virtual shells" or "graphic shells."The Shell under the Unix/linux operating system is both an interface for user interaction and a scripting language for control systems. This, of course, differs from the command line under Windows, although it also provides a very simple control st

Linux Basics--linux File system and Bash's basic featuresA. linux file system:A file in a Linux file system is a collection of data that contains not only the data in the file but also the structure of the file system, where all Linux