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# This file is a part of Julia. License is MIT: http://julialang.org/license
if is_windows()
const ERROR_ENVVAR_NOT_FOUND = UInt32(203)
_getenvlen(var::Vector{UInt16}) = ccall(:GetEnvironmentVariableW,stdcall,UInt32,(Ptr{UInt16},Ptr{UInt16},UInt32),var,C_NULL,0)
_hasenv(s::Vector{UInt16}) = _getenvlen(s) != 0 || Libc.GetLastError() != ERROR_ENVVAR_NOT_FOUND
_hasenv(s::AbstractString) = _hasenv(cwstring(s))
function access_env(onError::Function, str::AbstractString)
var = cwstring(str)
len = _getenvlen(var)
if len == 0
return Libc.GetLastError() != ERROR_ENVVAR_NOT_FOUND ? "" : onError(str)
end
val = zeros(UInt16,len)
ret = ccall(:GetEnvironmentVariableW,stdcall,UInt32,(Ptr{UInt16},Ptr{UInt16},UInt32),var,val,len)
if (ret == 0 && len != 1) || ret != len-1 || val[end] != 0
error(string("getenv: ", str, ' ', len, "-1 != ", ret, ": ", Libc.FormatMessage()))
end
pop!(val) # NUL
return transcode(String, val)
end
function _setenv(svar::AbstractString, sval::AbstractString, overwrite::Bool=true)
var = cwstring(svar)
val = cwstring(sval)
if overwrite || !_hasenv(var)
ret = ccall(:SetEnvironmentVariableW,stdcall,Int32,(Ptr{UInt16},Ptr{UInt16}),var,val)
systemerror(:setenv, ret == 0)
end
end
function _unsetenv(svar::AbstractString)
var = cwstring(svar)
ret = ccall(:SetEnvironmentVariableW,stdcall,Int32,(Ptr{UInt16},Ptr{UInt16}),var,C_NULL)
systemerror(:setenv, ret == 0)
end
else # !windows
_getenv(var::AbstractString) = ccall(:getenv, Cstring, (Cstring,), var)
_hasenv(s::AbstractString) = _getenv(s) != C_NULL
function access_env(onError::Function, var::AbstractString)
val = _getenv(var)
val == C_NULL ? onError(var) : unsafe_string(val)
end
function _setenv(var::AbstractString, val::AbstractString, overwrite::Bool=true)
ret = ccall(:setenv, Int32, (Cstring,Cstring,Int32), var, val, overwrite)
systemerror(:setenv, ret != 0)
end
function _unsetenv(var::AbstractString)
ret = ccall(:unsetenv, Int32, (Cstring,), var)
systemerror(:unsetenv, ret != 0)
end
end # os test
## ENV: hash interface ##
"""
EnvHash() -> EnvHash
A singleton of this type provides a hash table interface to environment variables.
"""
mutable struct EnvHash <: Associative{String,String}; end
"""
ENV
Reference to the singleton `EnvHash`, providing a dictionary interface to system environment
variables.
"""
const ENV = EnvHash()
similar(::EnvHash) = Dict{String,String}()
getindex(::EnvHash, k::AbstractString) = access_env(k->throw(KeyError(k)), k)
get(::EnvHash, k::AbstractString, def) = access_env(k->def, k)
in(k::AbstractString, ::KeyIterator{EnvHash}) = _hasenv(k)
pop!(::EnvHash, k::AbstractString) = (v = ENV[k]; _unsetenv(k); v)
pop!(::EnvHash, k::AbstractString, def) = haskey(ENV,k) ? pop!(ENV,k) : def
delete!(::EnvHash, k::AbstractString) = (_unsetenv(k); ENV)
setindex!(::EnvHash, v, k::AbstractString) = _setenv(k,string(v))
push!(::EnvHash, k::AbstractString, v) = setindex!(ENV, v, k)
if is_windows()
start(hash::EnvHash) = (pos = ccall(:GetEnvironmentStringsW,stdcall,Ptr{UInt16},()); (pos,pos))
function done(hash::EnvHash, block::Tuple{Ptr{UInt16},Ptr{UInt16}})
if unsafe_load(block[1]) == 0
ccall(:FreeEnvironmentStringsW, stdcall, Int32, (Ptr{UInt16},), block[2])
return true
end
return false
end
function next(hash::EnvHash, block::Tuple{Ptr{UInt16},Ptr{UInt16}})
pos = block[1]
blk = block[2]
len = ccall(:wcslen, UInt, (Ptr{UInt16},), pos)
buf = Array{UInt16}(len)
unsafe_copy!(pointer(buf), pos, len)
env = transcode(String, buf)
m = match(r"^(=?[^=]+)=(.*)$"s, env)
if m === nothing
error("malformed environment entry: $env")
end
return (Pair{String,String}(m.captures[1], m.captures[2]), (pos+(len+1)*2, blk))
end
else # !windows
start(::EnvHash) = 0
done(::EnvHash, i) = (ccall(:jl_environ, Any, (Int32,), i) === nothing)
function next(::EnvHash, i)
env = ccall(:jl_environ, Any, (Int32,), i)
if env === nothing
throw(BoundsError())
end
env = env::String
m = match(r"^(.*?)=(.*)$"s, env)
if m === nothing
error("malformed environment entry: $env")
end
return (Pair{String,String}(m.captures[1], m.captures[2]), i+1)
end
end # os-test
#TODO: Make these more efficent
function length(::EnvHash)
i = 0
for (k,v) in ENV
i += 1
end
return i
end
function show(io::IO, ::EnvHash)
for (k,v) = ENV
println(io, "$k=$v")
end
end
"""
withenv(f::Function, kv::Pair...)
Execute `f()` in an environment that is temporarily modified (not replaced as in `setenv`)
by zero or more `"var"=>val` arguments `kv`. `withenv` is generally used via the
`withenv(kv...) do ... end` syntax. A value of `nothing` can be used to temporarily unset an
environment variable (if it is set). When `withenv` returns, the original environment has
been restored.
"""
function withenv{T<:AbstractString}(f::Function, keyvals::Pair{T}...)
old = Dict{T,Any}()
for (key,val) in keyvals
old[key] = get(ENV,key,nothing)
val !== nothing ? (ENV[key]=val) : delete!(ENV, key)
end
try f()
finally
for (key,val) in old
val !== nothing ? (ENV[key]=val) : delete!(ENV, key)
end
end
end
withenv(f::Function) = f() # handle empty keyvals case; see #10853