21

I've quite forgotten: what file does one modify in order to add directories to $Path globally? Specifically, I want to include $UserBaseDirectory/ExtraPackges.

Or does one do it by means of modifying some setting in the OptionInspector (for Global Preferences) and, if so, which setting? I didn't see a relevant one under Global Options>File Locations.

Brett Champion
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murray
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    Szabolcs suggestion is not working for me. Anytime I quit Mathematica everything i added gets removed. I've tried running as an administrator and that doesn't help. – Ben Oct 19 '16 at 05:04

2 Answers2

28

You can add the following line:

AppendTo[$Path, FileNameJoin[{$UserBaseDirectory, "ExtraPackges"}]]

to the file:

FileNameJoin[{$UserBaseDirectory, "Kernel", "init.m"}]

init.m is described here, under "more information".

To do this automatically you can run:

With[
 {newPath = FileNameJoin[{$UserBaseDirectory, "ExtraPackges"}]},
 PutAppend[
  Unevaluated @ AppendTo[$Path, newPath],
  FileNameJoin[{$UserBaseDirectory, "Kernel", "init.m"}]
 ]
]
Kuba
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acl
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  • I suspected the method was to include such an AppendTo, but the issue was which init.m to use. Just to be sure: one uses init.m for Kernel, not for FrontEnd?

    And there's no way to do this via OptionInspector?

     – murray Feb 16 '12 at 17:16
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    I don't know if there is a way to do it from the Options Inspector. I tried the init.m in the indicated (Kernel) folder and it worked; my mental model of what is going on is: kernel gets started, loads init.m and runs it, then starts normal execution. So I just appended the path in there. Basically I think of it as autoexec.bat projected roughly 25 years into the future. – acl Feb 16 '12 at 17:23
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    @murray $Path is a kernel variable, so this needs to be done for Kernel/init.m, exactly as acl said. I don't think the front end could execute AppendTo at all.. – Szabolcs Feb 16 '12 at 17:40
  • OK, @Szabolics. So the obvious next question is: how could one learn that $Path is a kernel variable, unknown to the front end directly? – murray Feb 16 '12 at 23:54
2

You could modify the global options in the options editor (Win.OS**Ctr + Shif + O**).

look up the EvaluatorStartup and put code 

AppendTo[$Path, FileNameJoin[{$UserBaseDirectory, "ExtraPackges"}]]

into the value box and restart the frond end, check the $Path again. Note that ; is necessary to separate different codes.

enter image description here

Update: for multi-paths, use this code

If[!MemberQ[$Path, #] && DirectoryQ@#, 
   AppendTo[$Path, #]] & /@ {FileNameJoin[{$UserBaseDirectory, "ExtraPackges"}],"C:\\temp\\"}

if user defined package MyPackage` located in C:\temp\, then you can find the init.m by 

FindFile["MyPackage`"]

and load it with this code

Get[FindFile["MyPackage`"](*,CharacterEncoding -> "UTF8"*)(*optional*)]
Jerry
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