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authorDave Reisner <dreisner@archlinux.org>2012-04-25 22:27:19 -0400
committerDan McGee <dan@archlinux.org>2012-06-25 23:39:12 -0500
commitb58489d29a1898a4bff1b5da6ca4bfb14003dbfe (patch)
tree5c42f704cc671136ef43972cfdee1274e620e65f
parente183522e3168c4a31103b3c7910fa8d29333fb5a (diff)
downloadpacman-b58489d29a1898a4bff1b5da6ca4bfb14003dbfe.tar.xz
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>
-rw-r--r--Makefile.am2
-rw-r--r--scripts/Makefile.am3
-rw-r--r--scripts/library/README8
-rw-r--r--scripts/library/human_to_size.sh51
-rw-r--r--test/scripts/Makefile.am3
-rw-r--r--test/scripts/human_to_size_test.sh75
6 files changed, 140 insertions, 2 deletions
diff --git a/Makefile.am b/Makefile.am
index 7d6f3065..0010a3eb 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -41,6 +41,8 @@ test-vercmp: test/util src/util
test-parseopts: test/scripts scripts
$(BASH_SHELL) $(top_srcdir)/test/scripts/parseopts_test.sh \
$(top_srcdir)/scripts/library/parseopts.sh
+ $(BASH_SHELL) $(top_srcdir)/test/scripts/human_to_size_test.sh \
+ $(top_srcdir)/scripts/library/human_to_size.sh
# create the pacman DB and cache directories upon install
install-data-local:
diff --git a/scripts/Makefile.am b/scripts/Makefile.am
index 6bb72198..75699b2e 100644
--- a/scripts/Makefile.am
+++ b/scripts/Makefile.am
@@ -27,7 +27,8 @@ EXTRA_DIST = \
LIBRARY = \
library/output_format.sh \
- library/parseopts.sh
+ library/parseopts.sh \
+ library/human_to_size.sh
# Files that should be removed, but which Automake does not know.
MOSTLYCLEANFILES = $(bin_SCRIPTS)
diff --git a/scripts/library/README b/scripts/library/README
index c71c0714..44748ee2 100644
--- a/scripts/library/README
+++ b/scripts/library/README
@@ -27,3 +27,11 @@ Reccommended Usage:
Returns:
0: parse success
1: parse failure (error message supplied)
+
+human_to_size.sh:
+A function to convert human readable sizes (such as "5.3 GiB") to raw byte
+equivalents. base10 and base2 suffixes are supported, case sensitively. If
+successful, the converted byte value is written to stdout and the function
+returns 0. If an error occurs, nothing in written and the function returns 1.
+Results may be inaccurate when using a broken implementation of awk, such
+as mawk or busybox awk.
diff --git a/scripts/library/human_to_size.sh b/scripts/library/human_to_size.sh
new file mode 100644
index 00000000..11613207
--- /dev/null
+++ b/scripts/library/human_to_size.sh
@@ -0,0 +1,51 @@
+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)
+ }'
+}
diff --git a/test/scripts/Makefile.am b/test/scripts/Makefile.am
index b949e880..d525d894 100644
--- a/test/scripts/Makefile.am
+++ b/test/scripts/Makefile.am
@@ -1,5 +1,6 @@
check_SCRIPTS = \
- parseopts_test.sh
+ parseopts_test.sh \
+ human_to_size_test.sh
noinst_SCRIPTS = $(check_SCRIPTS)
diff --git a/test/scripts/human_to_size_test.sh b/test/scripts/human_to_size_test.sh
new file mode 100644
index 00000000..1d747946
--- /dev/null
+++ b/test/scripts/human_to_size_test.sh
@@ -0,0 +1,75 @@
+#!/bin/bash
+
+# source the library function
+if [[ -z $1 || ! -f $1 ]]; then
+ printf "error: path to human_to_size library not provided or does not exist\n"
+ exit 1
+fi
+. "$1"
+
+if ! type -t human_to_size >/dev/null; then
+ printf 'human_to_size function not found\n'
+ exit 1
+fi
+
+parse_hts() {
+ local input=$1 expected=$2 result
+
+ (( ++testcount ))
+
+ result=$(human_to_size "$1")
+ if [[ $result = "$expected" ]]; then
+ (( ++pass ))
+ else
+ (( ++fail ))
+ printf '[TEST %3s]: FAIL\n' "$testcount"
+ printf ' input: %s\n' "$input"
+ printf ' output: %s\n' "$result"
+ printf ' expected: %s\n' "$expected"
+ fi
+}
+
+summarize() {
+ if (( !fail )); then
+ printf 'All %s tests successful\n' "$testcount"
+ exit 0
+ else
+ printf '%s of %s tests failed\n' "$fail" "$testcount"
+ exit 1
+ fi
+}
+trap 'summarize' EXIT
+
+printf 'Beginning human_to_size tests\n'
+
+# parse_hts <input> <expected output>
+
+parse_hts '1MiB' 1048576
+
+parse_hts '10XiB' ''
+
+parse_hts '10 MiB' 10485760
+
+parse_hts '10 XiB' ''
+
+parse_hts '.1 TiB' 109951162778
+
+parse_hts ' -3 KiB ' -3072
+
+parse_hts 'foo3KiB' ''
+
+parse_hts '3KiBfoo' ''
+
+parse_hts '3kib' ''
+
+parse_hts '+1KiB' 1024
+
+parse_hts '+1.0 KiB' 1024
+
+parse_hts '1MB' 1000000
+
+parse_hts '1M' 1048576
+
+parse_hts ' 1 G ' 1073741824
+
+parse_hts '1Q' ''