Under Unix(tm), ``programs'' are ``executed'' by processes, either by the process interpreting information, or by a process replacing its image in memory with the binary program image stored in a file. In Unix(tm), a search path is used to find the program to be executed. The search path is stored in an environment variable called PATH, which consists of a sequence of directory names separated by `;'s. Each of the directories named in the sequence is searched in order for an executable file with the right name. Once found, the file is interpreted.