sum human readable file sizes with numfmt and awk

sum_filesize.sh

# Input: list of rows with format: "<filesize> filename", e.g.
# filesizes.txt
#######################
# 1000K  file1.txt
# 200M   file2.txt
# 2G     file3.txt
#

# Output:
cat filesizes.txt | numfmt --from=iec | awk 'BEGIN {sum=0} {sum=sum+$1} END {printf "%.0f\n", sum}'
2358222848
cat filesizes.txt | numfmt --from=iec | awk 'BEGIN {sum=0} {sum=sum+$1} END {printf "%.0f\n", sum}' | numfmt --to=iec
2.2G