callisto/man/environ/environ.3lua.scd

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ENVIRON(3lua) "3lua" "Callisto manual pages"
# NAME
*environ* - the process environment
# DESCRIPTION
The *environ* table contains a metatable allowing
indexes to get or set variables in the environment.
Variables and variable values are provided as strings.
The metatable's _\_\_index_ field returns
the value of the given variable.
This means any index into the *environ* table will yield the value of
the corresponding variable in the environment.
The metatable's _\_\_newindex_ field sets the given variable's value.
This means you can set any key in the *environ* table to set
the value of an environment variable.
The metatable's _\_\_pairs_ field returns an iterator function
allowing iteration over all variables in the environment using
the *pairs* library function.
# EXAMPLES
Get the value of the _HOME_ environment variable and use it to
set the _HOMEDIR_ environment variable:
local home = environ["HOME"]
environ["HOMEDIR"] = fs.dirname(home)
Print the values of every variable in the environment:
for var in pairs(environ) do
print(var .. " = " environ[var])
end
# SEE ALSO
callisto(3lua), process(3lua)