When a user inputs a line, the first few characters are checked for two special strings: the EOF string and the indirect character. Both terminators must start at the first character of the string. The EOF string (by default the /*) is a way of producing an end-of-file signal for the read. For terminal input, an equivalent way of generating an end-of-file is a CTRL-Z (this also can be used to terminate the previous input line). For example:
/* ! This is a generated EOF /* ! This is a single argument input string "/*".