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

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Interpretation Request #97
Topic: set -o noclobber Relevant Clauses: 3.7.2

The standard says: [n] <word Output redirection using the > format shall fail if the noclobber option is set and the file named by the expansion of word exists and is a regular file. This does not specify what happens in the case of an empty regular file. What does the POSIX standard require? Should an error result in the case of empty as well as nonempty files?

Interpretation Response
The standard does not make a distinction between empty or non-empty files. Further, the standard clearly states that "Output redirection using the > format shall fail if the noclobgber option is set" and conforming implementations must conform to this.

Rationale for Interpretation