System Commands OPPE 2: May 2022 (May 2022 term)

Write a sed script to

• Swap the first and second fields in the given input having field separator as a colon :.

• Replace every occurrence of the character ? if found at the end of a line to !.

Note: complete partial tasks for partial marking. Test case description: The input is the input file. And output is the output of running your sed script.

Write a sed script to

• Replace every three letter abbreviation of day of week to the respective number as given in the table. The abbreviation can be in any case or mixed case

  Abbreviation(case insensitive match)	Replace with
  sun	1
  mon	2
  tue	3
  wed	4
  thu	5
  fri	6
  Sat	7

• Change the first and third occurrences of the character ! to ., on each line.

Note: complete partial tasks for partial marking. Test case description: Input is the input file to sed. Output is the output printed on running your sed script.

Given a file that contains current years board exam scores of students in all the schools in an area. Each line in the file contains four comma-separated fields: school code, roll number of the student, name of the student, and marks in the below format.

School_code,Student_Roll_no,Name,Marks

All the fields could be alphanumeric values except the last field Marks which is a number less than 500, as the maximum marks of the exam is out of 500.

Write an AWK script to print the roll numbers of the toppers of each school. For example if there is marks details of students of 11 schools of an area in the file, then your output should contain 11 roll numbers in any order, one for each school.

Test case description: Input is the contents of the input file. Your script does not need to read any input. Output is the expected output from your script. Your script may print expected roll numbers in any order, evaluation script sorts the input before printing.