Inserting a character in certain column

[Michael Ulm]

Alexandra Zaharia wrote:
> On 2/25/08, Szemerédy Gábor <gaborszem at eccf.su.ac.yu> wrote:
>> Hello list!
>>  I need to insert a character in certain column in all rows of the file
>>  using vi.
>>  Please help
>>
> 
> If I understand correctly, suppose you have the file
> 
> aaaa
> bbbb
> cccc
> dddd
> 
> and you want to turn it into
> 
> aaaXYa
> bbbXYb
> cccXYc
> dddXYd
> 
> Then here's what you have to do in vi:
> 
--snip--

or use a regexp substitution. In command mode type

:%s/^.\{3}/&XY/

HTH,

Michael