Get a list of current variables in Julia Lang

Question

I am new to Julia Lang. I am coming from the background of Matlab.

In Matlab, when pressing whos command I will get all variables in the current scope; and also, I can store them in another variable like x=whos; Is there such commands exists in Julia? Example code in Matlab:

>> a=3; >> b=4; >> whos Variables in the current scope:  Attr Name        Size                     Bytes  Class ==== ====        ====                     =====  =====      a            1x1                          8  double     b            1x1                          8  double     prefix       1x16                        16  char  Total is 18 elements using 32 bytes. 

Answer 1

An Update:

whos()  

... is not working either in iJulia or at the command prompt in Julia-1.0.0.

It is working in Julia-0.6.4, though.

On the other hand,

varinfo() 

....prints information about the exported global variables in a module. For Example,

julia-1.0> varinfo() name                    size summary                         –––––––––––––––– ––––––––––– ––––––––––––––––––––––––––––––– Base                         Module                          Core                         Module                          InteractiveUtils 154.271 KiB Module                          Main                         Module                          PyPlot           781.872 KiB Module                          ans               50.323 KiB Plots.Plot{Plots.PyPlotBackend} myrepl               0 bytes typeof(myrepl)                  x                   88 bytes 1×6 Array{Int64,2}              y                    0 bytes typeof(y)                       

Hope, this is found useful.

Answer 2

You can use Julia's whos functions just like that Matlab command.

julia> whos() Base                          Module Core                          Module Main                          Module ans                           Nothing  julia> x = 5 5  julia> whos() Base                          Module Core                          Module Main                          Module ans                           Int64 x                             Int64 

Any modules (packages/libraries) you import into your local scope (using using) will also show up in the list (as Modules, like Base, Core, and Main above).

Additionally, you can ask about names exported by Modules. Base is the module containing the standard library.

julia> whos(Base) !                             Function !=                            Function !==                           Function $                             Function %                             Function &                             Function *                             Function +                             Function .... (lots and lots more) 

Considering that that result scrolls way off my screen, you can understand why you'd want to filter the results. For that you can use Regexes. (For more info on Julia's regexes, see this manual section)

julia> whos(r"M") Main                          Module  julia> whos(Base, r"Match"i) DimensionMismatch             DataType RegexMatch                    DataType each_match                    Function eachmatch                     Function ismatch                       Function match                         Function matchall                      Function 

I wasn't aware of the whos function before you asked, so thanks for helping me learn something new too. :)

Julia issue #3393 on github is about adding memory sizes to the whos output. It also references making whos return a value rather than just printing the information out.