bash - How to rearrange text file output result -

i write unix script following have ff result:

textfile1 contains following text:

    keyval1,1     keyval1,2     keyval1,3      keyval1,4     keyval2,1     keyval2,2     keyval3,1     keyval4,1     keyval4,3     keyval4,4 

expected result:

    keyval1 (1,2,3,4)     keyval2 (1,2)     keyval2 (1)     keyval4 (1,3,4) 

thank you.

i'm new unix , have done far. it's not working yet though :(

 #!/bin/ksh    f1 = 'cut -d "," -f 1 keyval.txt'   f2 = 'cut -d "," -f 2 keyval.txt'   while f1 <> f2     echo f1 "("f2")"     done   > output.txt 

you can in breeze using awk:

#!/usr/bin/awk -f begin {     fs = ","     closebracket = "" }  {     if (key != $1)     {         key = $1         printf "%s%s (%s", closebracket, key, $2     }     else     {         printf ",%s", $2     }      closebracket = ")\n" }  end {     printf "%s", closebracket }