Question

I want to filter the data from a text file in unix.
I have text file in unix as below:

A 200
B 300
C 400
A 100
B 600
B 700

How could i modify/create data as below from the above data i have in awk?

A 200 100
B 300 600 700
C 400 

i am not that much good in awk and i believe awk/perl is best for this.

Answer 1

awk 'END {
  for (R in r) 
    print R, r[R]
  }
{
  r[$1] = $1 in r ? r[$1] OFS $2 : $2
  }' infile

If the order of the values in the first field is important,
more code will be needed.
The solution will depend on your awk implementation and version.

Explanation:

r[$1] = $1 in r ? r[$1] OFS $2 : $2

Set the value of the array r element $1 to:

• if the key $1 is already present: $1 in r, append OFS $2
  to the existing value
• otherwise set it to the value of $2

expression ? if true : if false is the ternary operator.
See ternary operation for more.