bash - Merge two columns of a text file in Linux -

i have text file several columns of text , values. structure:

car       38      dog  42 cat       89 car       23      ape  18 

if column 1 has string, column 2 doesn't (or it's emptry string). , other way around: if column 1 empty, column 2 has string. in other words, "object" (car, cat, dog etc.) occurs in either column 1 or column 2, never both.

i'm looking efficient way consolidate column 1 , 2 file looks instead:

car  38 dog  42 cat  89 car  23 ape  18 

i can in bash script using while , if, i'm sure there simpler way of doing it. can help?

cheers! z

try this:

column -t file 

output:

 car  38 dog  42 cat  89 car  23 ape  18