1 Complete the following processes and job Manage related operation commands .
（1） Display the details of all files in the current directory through paging and run in the background .
（2） View the details of the current process of the system , And adjust the humility of the above process to -3.
（3） see Linux Current terminal background of the system job.
（4） Set a timing job, The system is required to 5 Send the message that the system is about to restart to all users in minutes .
（5） View and display all the timings job.
（6） Restrict users linuxuser1 and linuxuser2 Use timing job command .
（7） Set a periodicity job, The system is required to be in the morning 10 Click to view the system process status and save the results in ps.log In file .
2、 Text management related operation commands .
（1） Create a file in the home directory as profile.txt, The content of the document is student number 、 full name 、 major 、 Class information .
（2） Use awk Show /etc/passwd The line number and column number of each line of the file and the contents of the first and last Columns .
(3) stay /etc Find all the extensions in the directory .d file .