On 2/22/21 8:11 AM, Mike Jonkmans wrote:
Hi,
It seems some things are missing in the bash manual.
Notably definition of command and placements of coproc- and function-definition.
The section 'SHELL GRAMMAR' describes:
- simple-command
- pipeline
- list
- compound-command
- coproc
- function-definition
These are basically the `command' productions from the grammar. The
exception is `list', and it's there because it would be strange for
the reader if it were presented before simple commands and pipelines,
which users are more likely to encounter, even though a complete
command is technically a list.
Simplified, a pipeline is:
[ ! ] command1 [ | command2 ]
A list is a sequence of pipelines separated by ;, &, &&, or ||
and optionally terminated by ;, & or NL.
Within the list description, the and-list and or-list are described as:
and-list: command1 && command2
or-list: command1 || command2
Though the text says that and/or-lists are sequences of pipelines
(separated by && or ||).
`command1' and `command2' are meta-notation, not a grammar production.
That is slightly inconsistent.
Not really.
A pipeline can be reduced to a command.
In a sense, yes, depending on your definition of `command'.
In that case, the and/or list should read:
and-list: pipeline1 && pipeline2
or-list: pipeline1 || pipeline2
No, it really shouldn't.
The bash grammar is a little messier than that POSIX grammar in
https://pubs.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#tag_18_10_02
but it's basically the same.
Where are you trying to go with this?
--
``The lyf so short, the craft so long to lerne.'' - Chaucer
``Ars longa, vita brevis'' - Hippocrates
Chet Ramey, UTech, CWRU c...@case.edu http://tiswww.cwru.edu/~chet/
