删除除第一次出现的 Pattern 之外的所有匹配行

Question

I have the below lines

logs/backups
logs/backups/config_bk

logs/backups/cofig_bkp other/lines
and/some/more/lines

I have to search for a string "logs/backups" and need to delete all the lines which is having logs/backups except the first occurence... output which i need:

logs/backups

other/lines

and/some/more/lines

Answer 1

If the task is to preserve logs/backups , but not logs/backups/* , the solution is quite simple:

egrep  -v '^logs/backups.' <filename>

This will filter out (-v) any line that starts (represented by a caret) with 'logs/backups' and has at least one more chracter (represented by a dot).