diff options
Diffstat (limited to 'manual')
| -rw-r--r-- | manual/errno.texi | 26 |
1 files changed, 23 insertions, 3 deletions
diff --git a/manual/errno.texi b/manual/errno.texi index a68f3bdbae..3782e48c6a 100644 --- a/manual/errno.texi +++ b/manual/errno.texi @@ -831,9 +831,29 @@ sticky bit on a non-directory file; @pxref{Setting Permissions}. @comment POSIX.1: Function not implemented @deftypevr Macro int ENOSYS @comment errno 78 @c DO NOT REMOVE -Function not implemented. Some functions have commands or options defined -that might not be supported in all implementations, and this is the kind -of error you get if you request them and they are not supported. +Function not implemented. This indicates that the function called is +not implemented at all, either in the C library itself or in the +operating system. When you get this error, you can be sure that this +particular function will always fail with @code{ENOSYS} unless you +install a new version of the C library or the operating system. +@end deftypevr + +@comment errno.h +@comment POSIX.1: Not supported +@deftypevr Macro int ENOTSUP +@comment errno 118 @c DO NOT REMOVE +Not supported. A function returns this error when certain parameter +values are valid, but the functionality they request is not available. +This can mean that the function does not implement a particular command +or option value or flag bit at all. For functions that operate on some +object given in a parameter, such as a file descriptor or a port, it +might instead mean that only @emph{that specific object} (file +descriptor, port, etc.) is unable to support the other parameters given; +different file descriptors might support different ranges of parameter +values. + +If the entire function is not available at all in the implementation, +it returns @code{ENOSYS} instead. @end deftypevr @comment errno.h |