(#15872) Add to_bytes function

Converts a string like "2 MB" to the value in bytes. Useful for
comparisons on facts that return a human readable number instead of
machine readable.

1 files changed, 28 insertions, 0 deletions

diff --git a/lib/puppet/parser/functions/to_bytes.rb b/lib/puppet/parser/functions/to_bytes.rb
new file mode 100644
index 0000000..8ff73d1
--- /dev/null
+++ b/lib/puppet/parser/functions/to_bytes.rb
@@ -0,0 +1,28 @@
+module Puppet::Parser::Functions
+  newfunction(:to_bytes, :type => :rvalue, :doc => <<-EOS
+    Converts the argument into bytes, for example 4 kB becomes 4096.
+    Takes a single string value as an argument.
+    EOS
+  ) do |arguments|
+
+    raise(Puppet::ParseError, "to_bytes(): Wrong number of arguments " +
+          "given (#{arguments.size} for 1)") if arguments.size != 1
+
+    arg = arguments[0]
+
+    return arg if arg.is_a? Numeric
+
+    value,prefix = */([0-9.e+-]*)\s*([^bB]?)/.match(arg)[1,2]
+
+    value = value.to_f
+    case prefix
+    when '' then return value.to_i
+    when 'k' then return (value*(1<<10)).to_i
+    when 'M' then return (value*(1<<20)).to_i
+    when 'G' then return (value*(1<<30)).to_i
+    when 'T' then return (value*(1<<40)).to_i
+    when 'E' then return (value*(1<<50)).to_i
+    else raise Puppet::ParseError, "to_bytes(): Unknown prefix #{prefix}"
+    end
+  end
+end