Question on Escape-string

["John Zhang" <johnzhang06(at)gmail(dot)com>]

Dear all,

I am using pl/pgsql to develop a function to implement some logic to load
BLOB data, like .tif file, to postgres DB. The issue I am facing is the file
name MUST be with double back-slash \\ in order for pgsql to process the
string properly. However, when the string is Escaped in my function, how can
I pass it in to lo_import() function?

Is there any function to double back-slash a string? Or how can we preserve
a string as RAW?

---- ISSUE :
--         use E'C:\\tmp\\tst.tif' for the full file name for IN parameter
of load_blob function.
--         however, when the string is escaped it becomes 'C:\tmp\tst.tif'
as expected
--         the file name need be passed in to lo_import() function again
without double \\
--         when it is passed in and escaped , the \ is gone and the filename
becomes meaningless

Any input would be much appreciated!

Thanks a lot
John