Manipulate student records in shell script

packirisamy · 07-28-2014, 11:38 PM

I have a file student.dat with enteries like

ID NAME SUB1 SUB2 SUB3 SUB4 SUB5
1 adi 10 10 20 20 20

like this i have many entries. Now i need to find the total marks of all the student in another file say tot.dat. And the subject average in file named avg.dat.
Then i need to allocate grades for all the students in another file say grade.dat with entry like

ID Name Grade
1 adi A

CAN SOMEONE HELP ME???

notKlaatu · 07-28-2014, 11:51 PM

Your over all plan should go something like this:

1. sort the files so that each line is in the same order.
2. iterate (that is, loop) through the files line-by-line, doing this:
a. check the name to make sure the lines match as expected
b. extract the information you need.
c. dump the info into a new file.
3. move to the next file

There are lots of way to do this, but since it looks like you have pretty distinct fields to work with, I am thinking AWK (great tutorial on AWK here http://www.grymoire.com/Unix/Awk.html), although you could do it with cut, too.

Good luck!

pwalden · 07-28-2014, 11:55 PM

Sounds like you want someone to do your homework for you.

What do you want the solution in? Perl, awk, tcl, python, php, C, C++, Java, ... What is data source format? sqlite, mysql, mariaDB, csv, ...

eklavya · 07-29-2014, 02:20 AM

Suppose your file is like this :

Code:

ID NAME SUB1 SUB2 SUB3 SUB4 SUB5
1 adi 10 10 20 20 20
2 ben 15 16 13 12 15
3 cob 15 14 18 19 16
4 den 85 86 84 85 89
5 elf 78 45 25 65 23
6 foe 78 58 56 52 48
7 git 48 46 42 15 76
8 hen 78 45 12 16 19
9 ink 85 86 82 15 14
10 joe 49 46 13 15 18

And you want total and average of every student.

Code:

Run the following script.
#!/bin/bash
awk '
BEGIN {FS=OFS=" "}
{
sum=0; n=0
for(i=3;i<=NF;i++)
     {sum+=$i; ++n}
     print $0,"Sum:"sum,"Average:"sum/n
}' file.txt

In this example, first subject is third column that's why i=3