Interpretations

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

IEEE Standards Interpretation for IEEE Std 1003.1™-1990 IEEE Standard for Information Technology--Portable Operating System Interfaces (POSIX®)

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Interpretation Request #59
Topic: unlink() vs remove() Relevant Sections: 5.5

Does POSIX.1-1990 require that the ANSI C remove() function be effective when the filename argument is not a regular file? The question arises because several filename resolution assertions in 2003.1-1992 can be tested only if remove() is effective when filename is a directory.

My reading is that neither POSIX.1-1990 nor ANSI C makes any specific requirements. The rationale for remove() in ANSI C notes that remove is intended to be a portable replacement for the UNIX (now POSIX.1, too) unlink() function. A conforming implementation might implement remove() as a simple call to unlink(). However, I think that an implementation of remove() that fails when the argument is not the name of a regular file is also conforming.

Interpretation Response
The behavior for file types other than regular files is unspecified.

Rationale for Interpretation
There is no requirement in POSIX.1-1990 for remove() to succeed on file types other than regular file.

Editorial note
The proposed changes to IEEE Std 2003.1-1992 are as follows: Changes to remove() assertions 9 and 10, (8.1.33.4, lines 2047 and 2050) Replace "(A)" with "(C) If remove() supports directory file types:"