Question

Extract a particular column value from multiple files

ls -ltr

-rwxr-xr-x   4 dc staff   131 Feb 27 21:15 test.txt
-rwxr-xr-x   4 dc staff   134 Feb 25 21:15 test1.txt

test.txt and test1.txt (similar structure) contains a table structure like

cat test.txt

RECORD #1 DETAILS

    sl no.  regno  name  age
     1       20    ABC   10

cat test1.txt

RECORD #2 DETAILS

      sl no.  regno  name  age
       1       21    DEF   11

I want to extract the 2nd column value from all .txt files and store it into some other files.

Ouput.txt should be

test.txt 20
test1.txt 21

Answer 1

It’s not exactly clear what you are looking for, but if you just want to print the second column of the 4th line (and that is the ambiguity, as it’s not clear if you always want the data from line 4, or the data from 3 lines after ^RECORD, or data from the line after each occurrence of "sl no.", etc), you could do:

$ awk 'FNR == 4 { print FILENAME, $2 }' test.txt test1.txt

or, if you are using an awk that does not support FILENAME (at the moment, I’m not sure if that is standard or a gnu extension) and you are not using csh or one of its cousins, you could do:

$ for n in test.txt test1.txt; do printf '$s ' $n; awk 'NR==4{ print $2}' $n; done