On Wed, Dec 11, 2024 at 07:44:02PM -0500, Lawrence Velázquez wrote: > On Wed, Dec 11, 2024, at 3:50 AM, Mike Jonkmans wrote: > > Or worse: '! true | ! true' is a syntax error!? > > Also errors in dash, but not in ksh. > > Can a command - as part of a pipeline - not be a pipeline? > Not directly, no. > https://pubs.opengroup.org/onlinepubs/9799919799/utilities/V3_chap02.html#tag_19_10_02
Yes, the posix grammar doesn't allow it. But it is not clear, from the bash documentation, that a pipeline is not a command. Moreover, bash accepts e.g.: ! ! false How can you parse that, without a pipeline being a command? Note that this is not posix, though bash accepts it even with --posix. And, as said, ksh allows the construct (! true | ! true). It is not impossible, it just is not posix. > > What bothers me (only slightly), is the documentation. > Judging by this thread, some clarification would be worthwhile. ! false -- Regards, Mike Jonkmans