Environment variables [XL]

• environ(i:integer) -> string [XL]
• getenv(self:string) -> string
• isenv?(v:string) -> boolean [XL]
• maxenv() -> integer [XL]
• setenv(s:string) -> void [XL]

Additionally to the CLAIRE getenv method, XL CLAIRE provides some tools that make possible to change an environment variable (setenv) or iterate over the whole environment of the process (environ/maxenv) as in :

(for i in (1 .. maxenv())      let (v, val) := explode_wildcard(environ(i), "*=*")      in (assert(getenv(v) = val),          printf("~A = ~S\n", v, val)))

Note that setenv and

environ(i:integer) -> string

environ(i) returns the i^thenvironment variable (1 based index) in the form "var=value".

getenv(self:string) -> string

getenv(s) returns the value of the environment variable s if it exists and an empty string otherwise.

isenv?(v:string) -> boolean

isenv?(v) tests the existence of the environment variable v.

maxenv() -> integer

maxenv() returns the index of the last environment variable. For instance :

for i in (1 .. maxenv()) printf("~A\n", environ(i))

printf the process environment in the same way as the env shell command.

setenv(s:string) -> void

setenv(s) adds or updates an environment variable defined by s = "var=value".