getEnv -package:base
getEnv looks up a variable in the environment.
getEnv looks up a variable in the environment.
getEnv looks up a variable in the environment.
Get the current environment from the monad.
Computation
getEnv var returns the value of the
environment variable
var. For the inverse, the
setEnv
function can be used.
This computation may fail with:
Returns the value of an environment variable.
On UNIX, the name and value are byte strings which might or might not
be in some consistent character set and encoding. On Windows, they are
in UTF-8. On Windows, in case the environment variable's value
contains references to other environment variables, they are expanded.
Return
Just the value of the environment variable, or
Nothing if the variable is not set. The environment variable is
tracked as a dependency, and if it changes the rule will rerun in
subsequent builds. This function is a tracked version of
getEnv
/
lookupEnv from the base library.
flags <- getEnv "CFLAGS"
cmd "gcc -c" [out] (maybe [] words flags)
Deprecated: use get_env or get_env_text
Extract a specific data type from the environment.
Get the current environment
Returns the value of an environment variable
getEnvDefault is a wrapper around
getEnv where the
programmer can specify a fallback if the variable is not found in the
environment.
getEnvironment retrieves the entire environment as a list of
(key,value) pairs.
getEnvDefault is a wrapper around
getEnv where the
programmer can specify a fallback as the second argument, which will
be used if the variable is not found in the environment.