Converts all the non printable characters of blob->data into the \xxx representation where xxx is the octal representation of the byte, and the '\' (backslash) character is converted to "\\".
a maximum len used to truncate, or 0 for no maximum length
a new string from blob
Converts all the non printable characters of blob->data into the \xxx representation where xxx is the octal representation of the byte, and the '\' (backslash) character is converted to "\\".