If you don't care about order: 

$ sort -u tt.txt
123
133
3243
a
b
c

[download]

If you do: 

$ perl -ne'$s{$_}++||print' tt.txt
a
b
c
123
3243
133

[download]

Same, but one char shorter: (requires Perl 5.10 or higher) 

$ perl -nlE'$s{$_}++||say' tt.txt
a
b
c
123
3243
133

[download]

In reply to Re: one line for combining line by ikegami
in thread one line for combining line by xiaoyafeng

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