What command can I use in Linux bash script for summing up variable lines of numeric data into two s-CodePudding

I would like to create linux script line that goes through each line of the output and adds up the 2nd column of numbers and also separately sums up the 4th column of numbers, to then print out both sums

$ df | grep "/mnt" | sort -n -k2 -r
/dev/sdb1      2883220084     90152 2853810896   1% /mnt/b
/dev/sda1      1952208720 290495232 1642161972  16% /mnt/a
/dev/sdc1       975584768     77856  965722916   1% /mnt/c
/dev/sdd1       975584748     77852  965722900   1% /mnt/d
/dev/sde2       107003844        24  101522180   1% /mnt/e

This line only does it for the largest line. I'd like for it to add all lines.

$ df | grep "/mnt" | sort -n -k2 -r | head -1 | awk '{print $2" "$4}'

How can I do that, please?

CodePudding user response：

No need for greping, sorting or head.

df | awk '/\/mnt/{a =$2;b =$4}END{printf "%s\t%s\n",a,b}'

awk processes every line that matches /mnt, adding the values of $2 in a, and $4 in b. Once processing is done (in the END statement) we print them.

CodePudding user response：

Pure Bash:

#! /bin/bash
exec <<EOF
/dev/sdb1      2883220084     90152 2853810896   1% /mnt/b
/dev/sda1      1952208720 290495232 1642161972  16% /mnt/a
/dev/sdc1       975584768     77856  965722916   1% /mnt/c
/dev/sdd1       975584748     77852  965722900   1% /mnt/d
/dev/sde2       107003844        24  101522180   1% /mnt/e
EOF

sum2=0
sum4=0
while read c1 c2 c3 c4 rest; do
  let sum2 =$c2 sum4 =$c4
done
printf '%s\n' "$sum2" "$sum4"