linux job scheduler

the cursor;U restore the previous operation;Ctrl+r redo the previous operation;Vim b.txt new file;I enter the edit mode ("Insert" in the lower left corner);ESC exits edit mode;: w Save the edited data;: Q Exits.: Wq save exit.: q! Modified files, do not want to store, forced to leave without saving the file.A. Linux common Commandsmkdir dirname New FolderCD ~ Go to your home directoryCD dirname into the directory named dirname;• Displays the file an

how the operating system worksOne, function call stack1, computer work three magic weaponStorage program computer, interrupt mechanism, stack2, Stack is the C language program must be run when a record call path and parameter space-Function Call Framework-Pass parameters-Save return address-Provides local variable space3. Stack-related registers-ESP, stack pointer, point to top of stack-EBP, base point pointer, to the bottom of the stack, in C language as the record current function call base.4.

-39, find all the users in/etc directory have write permission files;Find/etc/-perm-222-ls10. Find all files that are larger than 1M in/etc directory and are of normal file type;find/etc/-size +1m-a-type f-ls11, find/etc/init.d/directory, all users have execute permission, and other users have write permission files;Find/etc/init.d-perm-113-ls12. Find files that do not belong to root, bin or hadoop in the/usr directory; find/usr/-not\ (-userroot-o-userbin-o-userhadoop \) -ls 13, to find at l

1 , how to change the automatically indented characters from the default eight to four: Set tabstop=42 , copy the/etc/grub2.cfg configuration file to the/tmp directory, and use the Find and replace command to delete the beginning blank character in the fileCENTOS6 Copy the/etc/grub.conf:%[email protected]^[[:space:]]@@g3 , copy the/etc/rc.d/init.d/functions file to the/tmp directory, use the Find and replace command as a line that begins with a blank character in the file, add a # to the beginni

with. D in the/etc directory to the/tmp/magedu.com directorymkdir/tmp/magedu.comCp-r/etc/*.d/tmp/magedu.com/ Description:-R recursion, which includes subdirectories.Also try some parameters, when the/tmp/magedu.com path does not exist, you need to first build this directory, and then copy.Exercise 3:1) Replace the lowercase letter in the/tmp/readme.test file with uppercase letters and write the results to the new file 1.txt tr [A-z] [a-z] (note that there are spaces between the two brackets)

Chapter 23rd UNIX File SystemNamed pipe Mkfifo:mkfifo [-M mode] pipe. Named pipes must be created explicitly and will not disappear (the RM command can be removed).The proc file is a pseudo-file used to access kernel information. For example, if a process ID is 1952, the process-related information can be found in a file in the/proc/1952 directory.The VFS (virtual file system) implements the details of file processing.24th Directory Operations~ Represents the home directory; CD-you can switch to

-ip-tool 172.25.254.X is executed in the system*) will automatically display the output of the ifconfig command*) System IP is set to: 172.25.254.X*) The system gateway is set to: 172.25.254.250*) The system DNS is set to: 172.25.254.250650) this.width=650; "Src=" Http://s4.51cto.com/wyfs02/M00/88/90/wKiom1f7fziizhiMAAE2jK36guQ797.png-wh_500x0-wm_3 -wmp_4-s_3899879340.png "title=" 13.png "alt=" Wkiom1f7fziizhimaae2jk36guq797.png-wh_50 "/>1. Package the/etc directory in the server host and compre

from 8 o'clock in the morning to 11.Command:3,15 8-11 * * commandExample 4:3rd and 15 minutes of every two-day 8 o'clock in the morning to 11-point executionCommand:3,15 8-11 */2 * commandExample 5:3rd and 15 minutes of each Monday from 8 o'clock in the morning to 11.Command:3,15 8-11 * * 1 commandExample 6:21:30 restart of SMB per nightCommand:* * * * */ETC/INIT.D/SMB restartExample 7:4:45 restart SMB per month for 1, 10, 22ndCommand:4 1,10,22 * */ETC/INIT.D/SMB restartExample 8:1:10 restart S