Answer to Question #180299 in UNIX/Linux Programming for Ritesh

Question

Consider a file “data.txt” which contains several records. Each record contains ID(7chars), 1 space, First name (10 chars),1 space, Second name (8 chars), 1space, marks in physics( 3chars), 1space, marks in chemistry(3 chars), 1space, marks in mathematics(3 chars) and anewline character.  Sample file content is as shown below:

71723 Ram        Sen        70 72 75

91924 Raghubir Yadav     82 73 80

53425 Ram        Chauhan 93 81 86

44917 Ratan      Yadav    95 79 91

Write a shell program info.sh to achieve the following

i)       If the programis run without any argument ($./info.sh), it has to display the first name, second name and average score of each student in the file.

Answer 1

#!/bin/bash

if [[ $# > 0 ]]; then
    echo "Command line arguments are not supported"
    exit 1
fi

sourceFile="data.txt" 

while IFS= read -r line
do
    firstName=${line:8:10}
    secondName=${line:19:8}
    physicsMarks=${line:28:3}
    chemistryMarks=${line:32:3}
    mathematicsMarks=${line:36:3}

    avg=$(((${physicsMarks} + ${chemistryMarks} + ${mathematicsMarks}) / 3))

    printf '%s %s %s\n' ${firstName} ${secondName} ${avg}

done < "$sourceFile"