Reading colums from a text file

Shell Programming and Scripting
1

Hi all,

I have a text file that has (4) columns. There are about 300 lines on this file. It is a plain text file. I am looking to write a simple script that will read each line from the file and generate another text file. The file looks something like this:

These are the columns:

StudentName Grade Class Teacher
StudentName2 Grade Class Teacher
...
...
...
StudentName300 Grade Class Teacher

What I need to do is extract the text from this file and re-arrange it into another file.

For example, this is how the new file would be arranged:

Teacher Class Grade StudentName

I can easily do it when a file has just a single line, like this:
-------------------
StudentName = `cat /fileName | awk '{print $1}'
Grade = `cat /fileName | awk '{print $2}'
Class = `cat /fileName | awk '{print $3}'
Teacher = `cat /fileName | awk '{print $4}'

echo "${Teacher} ${Class} ${Grade} ${StudentName}" >> /NewFile
-------------------

Where I am struggling is how would I do this for a file that has 300 lines instead of just one?

I am sure it is something simple, I just need to be pointed in the right direction.

Thanks in advance!

2

Print the fields in reverse:

[user@host ~]$ cat file
a b c d
a b c d
a b c d
a b c d
[user@host ~]$ awk '{for (i=NF;i>=1;i--){printf "%s ",$i} {print""}}' file
d c b a
d c b a
d c b a
d c b a
[user@host ~]$
3

Hint: How about using "one" awk command to read in all the records from the input file, print them in the required format and then output to new file?

4

Hi all, thanks for the quick responses. I guess I should have mentioned that that I also intend for the script to be able to use each filed as a variable aside from the sorting of the columns. For example, the sorting of the columns will be used to print a report, however, I would also like the script to generate the following text at the bottom of the report:

"The student, ${StudentName} is failing ${Teacher}'s ${Class} with a grade of ${Grade}"

Of course I will add a mechanism to check if the grade is passing or failing, but that I know how to do, It is the assigning variable values from multiple lines that is giving me trouble.

Thanks again in advanced.

5

You could do something like this to read the fields into a variable:

while read studentname grade class teacher
do
  echo "${teacher} ${class} ${grade} ${studentname}" >> /path/to/your/new_file
done </path/to/your/file