Please advice in this.
Input file
100,vvvt
201,unb
100,sos
301,abc
99,gang
desired output
99,gang
100,vvvt
100,sos
201,unb
301,abc
Means if first fields are same ( here 100) the do not sort.
After looking at the sort man page, what did you try?
I tried some option before putting question here.
It's file if you don't know like me.
Look at the man page. Specifically the "key" option. If you do a little searching you can see this question has been answered before.
You only needed one option. Show us what you tried!