WIP: Implement simple tilde expansion and globbing #3919
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OK, I went ahead and added simple globbing. Aside from the limitations listed above |
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FYI the Travis error on the 2nd patch seems totally unrelated (it couldn't build the items in the |
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I restarted the Travis build for you, everything looks green now. |
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Didn't know you could do that! |
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I'm not sure you can! It's only people who have some kind of permissions on this Github repo. You can find out if you can or not by dropping down the gear icon on the top right on that Travis page. Useful to figure out if something was a transient failure, or something really having to do with this code. |
| x = string(ENV["HOME"], x[2:end]) | ||
| end | ||
| if search(x, ['*', '?']) != 0 | ||
| paths = glob(x) |
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I wonder if this glob expansion should be eager (as it is here), or delayed until the command is spawned.
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When I first read this, I was inclined towards lazy (delayed until command execution), but then I realized that I would really like to be able to do this:
julia> `~./julia`
`/Users/stefan/.julia`which implies eager expansion. Likewise for globbing.
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Also, there are actually three times at which globbing can occur:
- at backtick parsing time
- at backtick evaluation time
- at command execution time
This is (1), you're talking about (3) and I think that (2) is actually right.
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Will any of these options fix this?
julia> ;ls a*
ERROR: Cannot access a*: no such file or directory
julia> ;cd ~/Documents; ls a*
ERROR: Cannot access a*: no such file or directory
julia> ;cd ~/Documents
/home/tim/Documents
julia> ;ls a*
./admin:
<...lots of files...>
./applications:
<...lots of files...>
...
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I'm not clear on what the issue is here. Can you explain what's happening?
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If I append two shell commands with a ;, for this to work as it does in the shell, the globbing needs to run after the cd command is finished. With the current buggy eager implementation (glob at parsing time), it tries to resolve a* before the cd command executes.
I'm vague on how spawn handles these things, but since it's a single backticks expression does that pose some challenges?
Or I could ask this another way: in the lazy vs eager discussion, I'm not quite on yours and @vtjnash's wavelength yet. I might need more examples of things that we want to work---and things we don't want to break---that might require some care in the implementation.
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Given that 0.2 seems to be approaching rapidly (and this feature has the potential for subtle breakage), and because I think that currently my "altruistic" coding time is better-spent on graphics, I'm going to let this one sit. I'm going to mark it "up for grabs" so no one expects that I'm going to get back to this anytime soon. |
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Yes, unfortunately, I think it needs the same level of careful attention that was spent on the original ability to call out to shell commands with shell-compatible escaping and quoting. Let's definitely wait until post-0.2. |
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More info for when that careful attention will be taken:
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Bump. Can this be put in shape quickly and merged, or should we move to 0.4? |
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Would be lovely. But I don't think I'm the right person for this particular job---it's just not my skill set. |
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This is a pretty tricky feature to really get right – and the kind of feature that it's better not to have than to have a broken version of. If people think it's a priority, I can work on it though. I believe that @kbara was working on proper user home directory lookup (which is a very difficult thing to do well portably). Maybe we can get that merged as a first step. |
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Is this closed because Tim indicated that continuing it was not in his wheelhouse? |
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So there are two pieces: user expansion and globbing. @vtjnash has implemented POSIX globbing in Glob.jl. A good approach to handling globbing would be to move the code from Glob.jl into Base and hook it up to backtick parsing. User expansion is a little harder. We need to use the correct APIs on each system for mapping user names to home directories – I'm not even sure that those APIs are. Maybe looking at an MIT or BSD-license shell implementation would be a good start. |
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Or python's On Tue, Mar 24, 2015 at 10:39 AM, Stefan Karpinski <[email protected]
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@blakejohnson, if it were an issue, then it should stay open until the issue was addressed. But this was a pull request---one that is probably not a good starting point for implementation---so I agree with @Keno's having closed it. |
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@StefanKarpinski I made some changes to the Unix implementation of |
This at least partially implements #1136. This does not support
~someotherusernotation.Once I learned more about how backticks worked, it was so dirt-simple that I'm suspicious this is overlooking something big. @StefanKarpinski in particular please review.
I'd really like to get this merged for 0.2. Globbing would be even nicer. Is shell-parse the right place to put that? It seems quite a bit more complicated.