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Interprocess communication in the ninth edition unix system

1990; Wiley; Volume: 20; Issue: S1 Linguagem: Inglês

10.1002/spe.4380201303

1097-024X

David L. Presotto, Dennis M. Ritchie,

Advanced Malware Detection Techniques

When processes wish to communicate, they must first establish communication. The stream mechanisms introduced in the Eighth Edition Unix system,1 which have now become part of AT&T's Unix System V2, provide a flexible way for processes to conduct an already-begun conversation with devices and with each other: an existing stream connection is named by a file descriptor, and the usual read, write, and I/O control requests apply. Processing modules may be inserted dynamically into a stream connection, so network protocols, terminal processing, and device drivers separate cleanly. However, these mechanisms, by themselves, do not provide a general way to create channels between processes. Simple extensions provide new ways of establishing communication. In our system, the traditional Unix IPC mechanism, the pipe, is a cross-connected stream. A generalisation of file-system mounting associates a stream with a named file. When the file is opened, operations on the file are operations on the stream. Open files may be passed from one process to another over a pipe. These low-level mechanisms allow construction of flexible and general routines for connecting local and remote processes.