Request to check:remove entries with duplicate numbers in first row

Shell Programming and Scripting
1

Hi

I have a file

1  xyz  456
1  xyz  456
1  xyz  456
2 abc  8459
3  gfd   657
4   ghf   658
4    ghf   658

I want the output

1  xyz  456
2 abc  8459
3  gfd   657
4   ghf   658

so if first column there is same number duplicated once again , romve the whole next duplicated row.

Please let meknow scripting

2 
perl -lne '$x{$_}++; END{print for(sort keys %x)}' file
3

Thanks for reply.

But its not providing expected output

as I think its checking by xyz also may be

I want it shuld check only 1

if one is more than once remove the whole row of second 1

so for example

1  xyz  456
1  xyz  456
1  xyz  456
2 abc  8459
3  gfd   657
4   ghf   658
4    ghf   658
5 xyz 456
6 gfd  657

the output shuld be

if xyz is more than once but with number 5 it shuld leave it as it is

1  xyz  456
 2 abc  8459
 3  gfd   657
 4   ghf   658
5 xyz 456
6 gfd  657
4

Try this:

awk '{s=$0;$1=$1} !a[$0]++{print s}' file