Reads an entire file into allocated memory, with good error checking.
If the call was successful, it returns TRUE and sets contents to the file contents and length to the length of the file contents in bytes. The string stored in contents will be nul-terminated, so for text files you can pass NULL for the length argument. If the call was not successful, it returns FALSE and sets error. The error domain is G_FILE_ERROR Possible error codes are those in the GFileError enumeration. In the error case, contents is set to NULL and length is set to zero.