IEEE Standards Interpretations for IEEE Std 1003.2™-1992 IEEE Standard for Information Technology--Portable Operating System Interfaces (POSIX®)--Part 2: Shell and Utilities
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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 188.8.131.52. 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()?
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