10 excellent Linuxshell script interview questions

Very good ten Linuxshell script interview questions 1. write a shell script to transfer files larger than 10 kb in the current directory to the/tmp Directory #/bin/sh # Programm: # Usingformovecurrentlydirectoryto/tmpforFileNamein 'ls-l |... very good ten Linux shell script interview questions 1. write a shell script to transfer files larger than 10 kb in the current directory to the/tmp Directory #/bin/sh # Programm: # Using for move currently directory to/tmp for FileName in 'ls-l | awk '$5> 10240 {print $9} ''do mv $ FileName/tmp done ls-al /tmp echo "Done! 2. write a shell script to get the network address of the local machine. For example, if the local IP address is 192.168.100.2/255.255.255.0, then its network address is 192.168.100.1/255.255.255.0 Method 1 :#! /Bin/bash # This script print ip and network file = "/etc/sysconfig/network-scripts/ifcfg-eth0" if [-f $ file]; then IP = 'grep "IPADDR" $ file | awk-F "=" '{print $2} ''MASK = 'grep" NETMASK "$ file | awk-F" = "'{print $2} ''echo" $ IP/$ MASK "exit 1 fi Method 2: #! /Bin/bash # This programm will printf ip/network # IP = 'ifconfig eth0 | grep 'inet '| sed's/^. * addr: // g' | sed's/Bcast. * $ // g'' NETMASK = 'ifconfig eth0 | grep 'inet '| sed's/^. * Mask: // g''echo "$ IP/$ NETMASK" exit 3. use Shell programming to determine whether a file is a character device file, if you copy it to the/dev directory. Reference Program :#! /Bin/sh FILENAME = echo "Input file name:" read FILENAME if [-c "$ FILENAME"] then cp $ FILENAME/dev fi 4. add comments for the following shell programs and describe the functions and call methods of the program :#! /Bin/sh #/etc/rc. d/rc. httpd # Start/stop/restart the Apache web server. # To make Apache start automatically at boot, make this # file executable: chmod 755/etc/rc. d/rc. httpd # case "$1" in 'start')/usr/sbin/apachectl start; 'stop')/usr/sbin/apachectl stop; 'restart ') /usr/sbin/apachectl restart; *) echo "usage $0 start | stop | restart"; esac reference answer: (1) program comment #! /Bin/sh defines the practical shell #/etc/rc. d/rc. httpd annotation line. all rows starting with the star number are annotation lines. # Start/stop/restart the Apache web server. # To make Apache start automatically at boot, make this # file executable: chmod 755/etc/rc. d/rc. httpd # case "$1" in # start of the case structure and determine the operation to be executed based on the "location parameter. This program carries a "location parameter", that is, $1 'start') # if the location parameter is start/usr/sbin/apachectl start; # start the httpd process 'stop ') # If the location parameter is stop/usr/sbin/apachectl stop; # stop the httpd process 'restart') # if the location parameter is stop/usr/sbin/apachectl restart ;; # restart the httpd process *) # if the location parameter is not start, stop, or restart, echo "usage $0 start | stop | restart"; # display command prompt information: program call method esac # case structure end (2) the function of the program is to start, stop or restart the httpd process (3) There are three ways to call the program: start, stop and restart. 5. design a shell program, add a new group named class1, and add 30 users to the group. The Username format is stdxx, where xx ranges from 01 to 30. Reference answer :#! /Bin/sh I = 1 groupadd class1 while [$ I-le 30] do if [$ I-le 9]; then USERNAME = stu0 $ {I} else USERNAME = stu $ {I} fi useradd $ USERNAME mkdir/home/$ USERNAME chown-R $ USERNAME/home/$ USERNAME chgrp-R class1 /home/$ USERNAME I =$ ($ I + 1 )) done 6. write a shell program to automatically delete 50 accounts. The account name is stud1 to stud50. Reference Program :#! /Bin/sh I = 1 while [$ I-le 50] do userdel-r stud $ {I} I = $ ($ I + 1) done 7. A system administrator needs to do some repetitive work every day. prepare a solution according to the following requirements: (1) at 4 pm: 50 delete all subdirectories and all files in the/abc directory; (2) from ~ At pm, all data in the first domain of each line in the x1 file under the/xyz directory is read to the bak01.txt file under the/backupdirectory. (3) archive and compress all directories and files under the/data directory at pm every Monday as files: backup.tar.gz; (4) unmount the CD-ROM of the IDE interface at PM (assuming: the device name for the CD-ROM is hdc); (5) it starts up before am. Reference answer: Solution: (1) use vi to create and edit a crontab file named prgx; prgx file content: 50 16 * rm-r/abc/* (2), 0 8-18/1 *** cut-f1/xyz/x1>;/backup/bak01.txt (3), 50 17 *** tar zcvf backup.tar.gz/data (4), 55 17 * umount/dev/hdc (5), logged on by a super user, and used crontab to execute the content in the prgx File: root @ xxx: # crontab prgx; crontab can be automatically started after it is started up before every morning. ---------------------------------------------- 8. design a shell program, back up and compress all contents in the/etc directory on the first day of every month, and store them in the/root/bak Directory. the file name is in the following format: yymmdd_etc, and yy is a year, mm indicates the month and dd indicates the day. The Shell program fileback is stored in the/usr/bin directory. Reference answer: (1) write the shell program fileback :#! /Bin/sh DIRNAME = 'ls/root | grep bak 'if [-z "$ DIRNAME"]; then mkdir/root/bak cd/root/bak fi YY = 'date + % Y' MM = 'date + % M' DD = 'date + % d' backetc1_1_yy1_mm1_dd_etc.tar.gz tar zcvf $ BACKETC/etc echo "fileback finished! "(2) compile the task timer: echo" 0 0 1 **/bin/sh/usr/bin/fileback ">; /root/etcbakcron crontab/root/etcbakcron or use the crontab-e command to add a scheduled task: 0 1 ***/bin/sh/usr/bin/fileback 9. A common user wants to regularly back up/user/backup to the/tmp directory at 00:00 every Sunday. what should he do? (1) Method 1: Use the crontab-e command to create a crontab file. The format is as follows: 0 0 ** sun cp-r/user/backup/tmp (2) Method 2: create a file in your Directory. the file content is as follows: 0 ** sun cp-r/user/backup/tmp and then execute crontab file to make it take effect. 10. design a Shell program and create 50 directories under the/userdata Directory, that is, user1 ~ User50, and set the permissions for each directory. the permissions of other users are: read; the permissions of the file owner are: read, write, and execute; and the permissions of the group where the file owner is located are: read and execute. Reference answer: create a program Pro16 as follows :#! /Bin/sh I = 1 while [I-le 50] do if [-d/userdata]; then mkdir-p-m 754/userdata/user $ I with-m 754, you don't need to write the following sentence-p is a recursive Directory # chmod 754/userdata/user $ I echo "user $ I" let "I = I + 1" (or I = $ ($ I + 1 )) else mkdir/userdata mkdir-p-m/userdata/user $ I # chmod 754/userdata/user $ I echo "user $ I" let "I = I + 1" (or I = $ ($ I + 1 )) fi done