Interpretations

Answering questions that may arise related to the meaning of portions of an IEEE standard concerning specific applications.

IEEE Standards Interpretations for IEEE Std 1003.2™-1992 IEEE Standard for Information Technology--Portable Operating System Interfaces (POSIX®)--Part 2: Shell and Utilities

Copyright © 1996 by the Institute of Electrical and Electronics Engineers, Inc. 3 Park Avenue New York, New York 10016-5997 USA All Rights Reserved.

Interpretations are issued to explain and clarify the intent of a standard and do not constitute an alteration to the original standard. In addition, interpretations are not intended to supply consulting information. Permission is hereby granted to download and print one copy of this document. Individuals seeking permission to reproduce and/or distribute this document in its entirety or portions of this document must contact the IEEE Standards Department for the appropriate license. Use of the information contained in this document is at your own risk.

IEEE Standards Department, Copyrights and Permissions, 445 Hoes Lane, Piscataway, New Jersey 08855-1331, USA

Interpretation Request #134
Topic: wordexp() and IFS Relevant Sections: B.9 and 3.6

Just as is expected by the accompanying rationale, our implementation of wordexp() executes a shell subprocess to do the word expansions. We use the Korn shell (the one used as the basis for the POSIX.2 shell) which resets its IFS on startup, as permitted by subclause 4.56.5.3. The test assertions for wordexp() presume that a modified IFS setting will be reflected in its field splitting, and that a reset IFS is non- conformant. Is this the expected POSIX.2 behavior for wordexp()?

Interpretation Response
The standard clearly states the requirements for word expansion and conforming implementations must conform to this. The fact that IFS can be reset does not preclude implementations using the shell.

Rationale for Interpretation
None.