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For a .rda file, after loading it, except viewing it using Rtudio window, are there any functions that can list all the data information stored in this rda file?

user297850
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1 Answers1

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When I want to see what's in an .rda file without loading it into my current environment, I load it into a temp env:

e <- new.env(parent = emptyenv())
load("path/to/file.rda", envir=e)
ls(e)     # shows names of variables stored in it
ls.str(e) # shows a `str` presentation of all variables within it

Not the most efficient way, as it requires that you load the contents before listing them. I don't think it's easy to look at a raw rda file on-disk and know its contents without loading it in some fashion.

r2evans
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  • I just load the rda file directly, for instance, temp<-load("x.rda"), then ls(temp). I got error message as Error in as.environment(pos) : no item called "X" on the search list – user297850 Mar 03 '21 at 04:03
  • I suggest you read `?load`, where its return value is a *"character vector of the names of objects created"*, and not the objects themselves. The premise of `load` is to operate in *side-effect* instead of a functional load of objects. If you want/need the ability to load an object directly such as that (without side-effect), then you may want `saveRDS` and `readRDS`, though it saves only one object instead of `save`'s ability to save zero or more objects into a single `.rda` file. – r2evans Mar 03 '21 at 13:14