How to give space between columns?

Question

I have a text file as shown below.I would like to give a space between the character and number in the fifth column. How can I do this with awk?

cxe  911  bv  he         


        

Answer 1

$ awk 'match($0,/([^[:space:]]+[[:space:]]+){4}[^[:space:]]/) {
         print substr($0,1,RLENGTH), substr($0,RLENGTH+1) }' file
cxe  911  bv  heg   A 1029   53.030
bvf  912  cv  lya   A 1030   51.99

The "4" above is the number of columns before the one you're interested in, i.e. the 5th. If you want to operate on a different field, just change that number in the obvious way.

If you're using an older version of gawk you'd need to add the --re-interval flag but for newer gawks RE-intervals ({4}) are enabled by default.

Also, here's a briefer but GNU-awk specific solution if you prefer:

$ awk '{print gensub(/(([^[:space:]]+[[:space:]]+){4}[^[:space:]])(.*)/,"\\1 \\3","")}' file
cxe  911  bv  heg   A 1029   53.030
bvf  912  cv  lya   A 1030   51.99

You can do similar in any awk using a pair of sub()s but it's ugly so I'd use the match()/substr() for those awks.

Finally if, as some others have posted, you want a solution to add a space after the 21st character on each line rather than after the first character in the 5th field on each line then that'd just be:

$ awk 'sub(/.{21}/,"& ")' file
cxe  911  bv  heg   A 1029   53.030
bvf  912  cv  lya   A 1030   51.99