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pacman/scripts/library/human_to_size.sh
Dave Reisner b58489d29a scripts/library: add human_to_size
This is a bash wrapper around an awk function that parses human readable
sizes and returns their representative values in bytes, as a string. A
small test harness is added to validate the functionality.

Signed-off-by: Dave Reisner <dreisner@archlinux.org>
2012-06-25 23:39:12 -05:00

52 lines
1.1 KiB
Bash

human_to_size() {
awk -v human="$1" '
function trim(s) {
gsub(/^[[:space:]]+|[[:space:]]+$/, "", s)
return s
}
function parse_units(units) {
if (!units || units == "B")
return 1
if (match(units, /^.iB$/))
return 1024
if (match(units, /^.B$/))
return 1000
if (length(units) == 1)
return 1024
# parse failure: invalid base
return -1
}
function parse_scale(s) {
return index("BKMGTPE", s) - 1
}
function isnumeric(string) {
return match(string, /^[-+]?[[:digit:]]*(\.[[:digit:]]*)?/)
}
BEGIN {
# peel off the leading number as the size, fail on invalid number
human = trim(human)
if (isnumeric(human))
size = substr(human, RSTART, RLENGTH)
else
exit 1
# the trimmed remainder is assumed to be the units
units = trim(substr(human, RLENGTH + 1))
base = parse_units(units)
if (base < 0)
exit 1
scale = parse_scale(substr(units, 1, 1))
if (scale < 0)
exit 1
printf "%d\n", size * base^scale + (size + 0 > 0 ? 0.5 : -0.5)
}'
}