Issue
File_A
Name: John Smith
Grade: 8
Institute: Baldwin
Number of entries: 125
State: Texas
File_B
Name: David Buck
Grade: 9
Institute: High Prime
Number of entries: 123
State: California
There are many such similar files in which the Number of entries (present at line number 4 in all files) has to doubled.
For File_A it should be 250 and for File_B 246.
How to do this for all files in Linux?(using sed or awk or any other commands)
Tried commands:
sed -i '4s/$2/$2*2/g' *.txt (nothing happening from this)
awk "FNR==4 {sub($2,$2*2)}" *.txt (getting syntax error)
Solution
Thank you for all the answers. With your help I was able to figure out simple solution by understanding and combining your answers.
Here it is (which worked in my environment):
To display on terminal:
awk 'FNR==4 {sub($4,$4*2)} 1' File_A
To move to some file:
awk 'FNR==4 {sub($4,$4*2)} 1' File_A > temp_A
To perform changes inside file using inplace:
awk -i inplace 'FNR==4 {sub($4,$4*2)} 1' *.txt
$4
being 4th parameter in the line;
FNR==4
being the line number 4;
1
at the end helps in printing everything
Answered By - John809 Answer Checked By - Marilyn (WPSolving Volunteer)