Unix and other file systems have the concept of an execute/search permission. If a file has execute permission, then the file is a program which may be loaded and run. If an attempt is made to run a file which does not have execute permission, then an error condition results. Execute/search permissions may also be used with directories. If a directory has search permission, then the directory can become the default directory or may be part of a complete path reference to a file. This is to be distinguished from a directory with read permission which means that the contents of the directory may be read.
Not all file systems have the concept of an execute/search permission. This is not so much of a problem if the server file system has execute/search permissions and the client does not. However, if the client has execute/search permissions and the server does not, then it will be difficult on the client to maintain the semantics associated with execute/search permissions. One solution is to not permit executable files to be run from a server whose file system cannot support execute/search permissions. Another solution is for the client to interpret the read permission as the execute/search permission.