[SOLVED] Remove the trailing commas at the first and last row only

Issue

I am wondering how I can remove the trailing commas at the first and last row only (still keeping the other commas in there).

I found some similar questions but exactly the same.

Sample input:

000N5,DBS,103151201409220007770001,,,,,,,,,,,,,,,,,,,,,,,,,,,,
10,1256,19700802,,,,SMITH,,ABC,,1,,,,,,GX1 4NL,,  
10,1256,19690802,,,,WilliAM,,XX,,1,,,,,,Gl15 4MX,,  
101RN5,DBS,103151201409220007770001,,,,,,,,,,,,,,,,,,,,,,,,,,,, 

Expected output:

000N5,DBS,103151201409220007770001
10,1256,19700802,,,,SMITH,,ABC,,1,,,,,,GX1 4NL,,  
10,1256,19690802,,,,WilliAM,,XX,,1,,,,,,Gl15 4MX,,
101RN5,DBS,103151201409220007770001

Solution

Reasonably easy in sed;

sed -i~ -e '1!{' -e '$!b' -e } -e 's/,*$//' filename

The braces select lines which are not the first (1!) and also not the last ($!) and skip b to the end of the script. For remaining lines, we proceed into the s/.../.../ which replaces trailing commas with nothing.

The -i~ option says to save the original as a backup in filename~; if you don't want to keep a backup, pass an empty string (how exactly is slightly platform-dependent; on BSD and MacOS, you need -i '' whereas on e.g. Linux you can simply omit the '').

Answered By - tripleee

Answer Checked By - Gilberto Lyons (WPSolving Admin)