Thanks for the responses This feature already exist > https://github.com/apache/nuttx-apps/blob/master/nshlib/Kconfig#L126-L146 >
As far as I can understand, that is for backquotes `foo` which is a type of variable expansion. What I need is support for single quotes 'foo' which means that whatever is inside '' is just a string litral. Or do you mean that the variable expansion support is already there ? Does posix say something about shells? > Yes POSIX demands that the aliases are stored per session only. BR, Ville Juven > On Thu, Mar 9, 2023 at 12:35 PM Xiang Xiao <xiaoxiang781...@gmail.com> wrote: > On Thu, Mar 9, 2023 at 6:14 PM Ville Juven <ville.ju...@gmail.com> wrote: > > > Hi all, > > > > I'm in the process of writing support for shell aliases into NSH, but > since > > the shell is the front end for NuttX I decided to make a post here for > > opinions on this matter and to open discussion for requirements, mostly > to > > prevent unexpected regression issues that might arise from this. > > > > 1. Are shell aliases seen as something useful in the community ? I need > > them for a project of mine which is the reason I started implementing > > support but I'd like to know if they are seen as useful whatsoever by > > others. > > > > 2. To properly support aliases, the shell parser needs to support single > > quotes and double quotes. This support will generate a bit of extra code > > into the parser, is this seen as OK ? > > > > alias foo='bar baz' > > alias foo="bar $baz" > > > > In both cases, the parser stops on the first delimiter (whitespace) even > > though it is quoted. > > > > 3. I will implement support for *single quotes* as this is a simple case > > but not for double quotes as the rules are more complex (need to perform > > variable expansions etc). Is this seen as a blocker / fatal issue? > > > > > This feature already exist > https://github.com/apache/nuttx-apps/blob/master/nshlib/Kconfig#L126-L146 > > > > 4. I added a Kconfig option to turn alias support on/off, what should the > > default state of this option be ? Currently it is defined as follows: > > > > config NSH_ALIAS > > bool "Enable alias support" > > default !DEFAULT_SMALL > > > > I noticed that many of the shell features are flagged behind > DEFAULT_SMALL. > > > > Also the alias amount is configurable. > > > > 5. Currently aliases are implemented globally i.e. every shell shares the > > same aliases, is this seen as a problem or should I make the aliases > stick > > to a shell session only ? > > > > > It's better to follow the POSIX spec. > > This is my first time posting on this board, so apologies if I did > > something improper. > > > > Br, Ville Juven > > >
