Unix вопросы и ответы для интервью

Question: Construct pipes to execute the following jobs.</SPAN><SPAN class="answers">
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Answer: 1. Output of who should be displayed on the screen with value of total number of users who have logged in displayed at the bottom of the list.
2. Output of ls should be displayed on the screen and from this output the lines containing the word ?poem? should be counted and the count should be stored in a file.
3. Contents of file1 and file2 should be displayed on the screen and this output should be appended in a file
.
From output of ls the lines containing ?poem? should be displayed on the screen along with the count.
4. Name of cities should be accepted from the keyboard . This list should be combined with the list present in a file. This combined list should be sorted and the sorted list
should be stored in a file ?newcity?.
5. All files present in a directory dir1 should be deleted any error while deleting should be stored in a file ?errorlog?.