Printing the lines which are repeating in a files

Shell Programming and Scripting
1

Hi,

I need to find the lines which are repeating in a file
cat file1

abcdef 23-1
abcdef 24-1
bcdeff 25-0
ttdcfg 26-0
ttdcfg 20-0
bcdef1 25-0
bcdef2 25-0
bcdef3 25-0
bcdef4 25-0
bcdef4 00-0

any help is greatly appreciated. Thanks in advance.

In need to find which one are repating.
cat my_out_file

abcdef 23-1
abcdef 24-1
ttdcfg 26-0
ttdcfg 20-0
bcdef4 25-0
bcdef4 00-0
2

don't quite get your meaning.

example input/output

3

Like this?

$ cat x
abcdef 23-1
abcdef 24-1
bcdeff 25-0
ttdcfg 26-0
ttdcfg 20-0
bcdef1 25-0
bcdef2 25-0
bcdef3 25-0
bcdef4 25-0
bcdef4 00-0
$ 
$ awk '{print $1}' x |sort | uniq -d | fgrep -f - x
abcdef 23-1
abcdef 24-1
ttdcfg 26-0
ttdcfg 20-0
bcdef4 25-0
bcdef4 00-0
$

Lots of sub shells. Hope your actual file is not so huge.

4

Try this...

awk '$1 in a{print (a[$1]?a[$1]RS$0:$0);a[$1]="";next}{a[$1]=$0}' input_file

For only the first column

awk '$1 in a{print (a[$1]?$1RS$1:$1);a[$1]="";next}{a[$1]=$0}' input_file

HTH
--ahamed