Combine results of column one Then sum column 2 to list total for each entry in column one

Question

I am bit of Bash newbie, so please bear with me here.

I have a text file dumped by another software (that I have no control over) listing each user with number of ti

Answer 1

GNU datamash:

datamash -W -s -g1 sum 2 < input.txt

Output:

Bob 219
Jim 245
John    208
Mark    190
Richard 142
Sean    201

Answer 2

Pure Bash:

declare -A result                 # an associative array

while read name value; do
  ((result[$name]+=value))
done < "$infile"

for name in ${!result[*]}; do
  printf  "%-10s%10d\n"  $name  ${result[$name]}
done

If the first 'done' has no redirection from an input file this script can be used with a pipe:

your_program | ./script.sh

and sorting the output

your_program | ./script.sh | sort

The output:

Bob              219
Richard          142
Jim              245
Mark             190
John             208
Sean             201

Answer 3

This sounds like a job for awk :) Pipe the output of your program to the following awk script:

your_program | awk '{a[$1]+=$2}END{for(name in a)print name " " a[name]}'

Output:

Sean 201
Bob 219
Jim 245
Mark 190
Richard 142
John 208

The awk script itself can be explained better in this format:

# executed on each line
{
  # 'a' is an array. It will be initialized 
  # as an empty array by awk on it's first usage
  # '$1' contains the first column - the name
  # '$2' contains the second column - the amount
  #
  #  on every line the total score of 'name' 
  #  will be incremented  by 'amount'
  a[$1]+=$2
}
# executed at the end of input
END{
  # print every name and its score
  for(name in a)print name " " a[name]
}

Note, to get the output sorted by score, you can add another pipe to sort -r -k2. -r -k2 sorts the by the second column in reverse order:

your_program | awk '{a[$1]+=$2}END{for(n in a)print n" "a[n]}' | sort -r -k2

Output:

Jim 245
Bob 219
John 208
Sean 201
Mark 190
Richard 142