Dear Reader, Below are three odd man out questions based on linux concepts. Though you may not expect these kinds of questions in placement tests, these questions can certainly help to assess your understanding of the concepts. Having said that these questions may be bit tough especially if you are unfamiliar to linux.
a) cron b) crontab c) scheduler d) crond
Answer : c) scheduler
cron jobs are those jobs that are invoked automatically at predefined time intervals. These can be edited with the help of crontab command. The linux daemon (background tasks are called daemons in linux) responsible for these jobs is crond. However, scheduler is similar to cron but is specific to windows servers. Hence cron,crontab and crond are related to each other.
Hint : The options given in this question are commands used in linux :
a) cd b) pwd c) ls d) sar
Answer : d) sar
cd command takes you to the specified directory. pwd command gives you the current working directory. ls command lists files and folders in a specified directory. These three commands are concerned with file and folder operations. However sar command gives the cpu utilization. Hence it is a different type of command.
a) open source b) GPL c) proprietary d) free
Answer : c) proprietary
Most of the linux distributions are open source softwares. This means that the source code will be distributed along with the OS. Most of them are released under GPL license. This license enables a user to modify and re-distribute with certain constraints. As you would be knowing, most distributions are free as well. However, other operating systems like those of windows are proprietary where you will not get the source code or the license to modify and distribute/sell.