Splitting the PATH variable

General Usage
,
1

I want to re-order path entries.

On unix, ENV["PATH"] = "/usr/local/bin:/usr/bin:/bin" or some such.
On windows, ENV["PATH"] = "c:\\usr\\local\\bin;c:\\usr\\bin;c:\\bin"
But it could be ENV["PATH"] = "c:\\usr\\local\\bin;c:\\usr\\bin;c:\\bin;\"c:\\usr\\directory name with; semicolon\\bin\"", so split(ENV["PATH"], Sys.iswindows() ? ";" : ":") isn’t perfect. Is there a better way?

3

PATH environment variables are not guaranteed to point to paths that exist in the system

4

OK, nevermind.

5

Why do you care? Most tools won’t work anyway if PATH includes directories with the list separator in their own path. Try for example this on Linux:

% mkdir -p /tmp/tmp:dir
% echo 'echo hello world' > /tmp/tmp:dir/helloworld
% chmod +x /tmp/tmp:dir/helloworld
% /tmp/tmp:dir/helloworld
hello world
% export PATH="/tmp/tmp:dir:${PATH}"
% helloworld                  
zsh: command not found: helloworld
1 Like
6

For the Windows case, an attempt at a splitpath() function:

# Julia 1.7:
function splitpath(epath::String)
    isw() = Sys.iswindows()
    ix = findall(occursin("\""), epath)
    if !isempty(ix)
        i0, p0 = 1, String[]
        for i in 1:2:length(ix)
            append!(p0, replace.(string.(split(epath[i0:ix[i]-1], isw() ? ";" : ":")), "\""=>""))
            push!(p0, replace.(string(epath[ix[i]:ix[i+1]-1]), "\"" => ""))
            i0 = ix[i+1]
        end
        if length(epath) > ix[end]
            append!(p0, replace.(string.(split(epath[ix[end]+1:end], isw() ? ";" : ":")), "\""=>""))
        end
    else
        p0 = string.(split(epath, isw() ? ";" : ":"))
    end
    filter!(!isempty,p0)
    return p0
end

# INPUT:
epath = "c:\\usr\\local\\bin;c:\\usr\\bin;c:\\bin;\"c:\\usr\\directory name with; semicolon\\bin\";c:;\"c:\\directory2 with; semicolon\""

# OUTPUT:
splitpath(epath)

6-element Vector{String}:
 "c:\\usr\\local\\bin"
 "c:\\usr\\bin"
 "c:\\bin"
 "c:\\usr\\directory name with; semicolon\\bin"
 "c:"
 "c:\\directory2 with; semicolon"
1 Like
7

Honestly, I was hoping there was a builtin akin to splitpath and joinpath that would do it. Given the complexity of @rafael.guerra’s answer, I may well stick with not supporting path entries with ;.

1 Like
8

Sorry but simplicity requires more time and skill :slight_smile: