[PATCH v2 1/2] common/rc: add _parse_size_string

[An Long <lan@suse.com>]

Add a helper to convert size value to bytes. This is used to handle
value as bytes, such as 4k to 4096.

Signed-off-by: An Long <lan@suse.com>
---
V1 -> V2:
 - Rename _parse_size_from_string to _parse_size_string
 - Remove unnecessary '$' sign
---
 common/rc | 48 ++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 48 insertions(+)

diff --git a/common/rc b/common/rc
index 3c072c16..09ffafa4 100644
--- a/common/rc
+++ b/common/rc
@@ -1028,6 +1028,54 @@ _check_minimal_fs_size()
 	fi
 }
 
+# Convert size value to bytes
+# _parse_size_string <size>
+_parse_size_string()
+{
+        local str=$1
+        local mult=1
+        local size
+        local endchar
+
+        if [[ $str =~ ^[0-9]+[a-zA-Z]$ ]] ; then
+                size=${str:: -1}
+                endchar=${str: -1}
+                case $endchar in
+                e|E)
+                                mult=$((mult * 1024))
+                                ;&
+                p|P)
+                                mult=$((mult * 1024))
+                                ;&
+                t|T)
+                                mult=$((mult * 1024))
+                                ;&
+                g|G)
+                                mult=$((mult * 1024))
+                                ;&
+                m|M)
+                                mult=$((mult * 1024))
+                                ;&
+                k|K)
+                                mult=$((mult * 1024))
+                                ;&
+                b|B)
+                                ;;
+                *)
+                                echo "unknown size descriptor $endchar"
+                                exit 1
+                esac
+        elif [[ $str =~ ^[0-9]+$ ]] ; then
+                size=$str
+        else
+                echo "size value $str is invalid"
+                exit 1
+        fi
+
+        size=$((size * mult))
+        echo $size
+}
+
 # Create fs of certain size on scratch device
 # _scratch_mkfs_sized <size in bytes> [optional blocksize]
 _scratch_mkfs_sized()
-- 
2.35.3