* Builtin function `getEnv' for getting environment variables.

This commit is contained in:
Eelco Dolstra 2006-09-24 17:48:41 +00:00
parent df8873e14a
commit e47e0c2dbe
4 changed files with 22 additions and 6 deletions

View file

@ -49,6 +49,13 @@ static Expr primImport(EvalState & state, const ATermVector & args)
if (matchPath(arg, arg2))
path = aterm2String(arg2);
else if (matchStr(arg, arg2)) {
path = aterm2String(arg2);
if (path == "" || path[0] != '/')
throw EvalError("`import' requires an absolute path name");
path = canonPath(path);
}
else if (matchAttrs(arg, es)) {
Expr a = queryAttr(arg, "type");
@ -67,8 +74,7 @@ static Expr primImport(EvalState & state, const ATermVector & args)
}
}
if (path == "")
throw TypeError("`import' requires a path or derivation as its argument");
else throw TypeError("`import' requires a path or derivation as its argument");
return evalFile(state, path);
}
@ -374,9 +380,6 @@ static Expr primDerivationStrict(EvalState & state, const ATermVector & args)
throw EvalError(format("derivation names are not allowed to end in `%1%'")
% drvExtension);
/* !!! the name should not end in the derivation extension (.drv).
Likewise for sources. */
/* Construct the "masked" derivation store expression, which is
the final one except that in the list of outputs, the output
paths are empty, and the corresponding environment variables
@ -702,6 +705,14 @@ static Expr primTail(EvalState & state, const ATermVector & args)
}
/* Return an environment variable. Use with care. */
static Expr primGetEnv(EvalState & state, const ATermVector & args)
{
string name = evalString(state, args[0]);
return makeStr(toATerm(getEnv(name)));
}
/* Apply a function to every element of a list. */
static Expr primMap(EvalState & state, const ATermVector & args)
{
@ -811,6 +822,7 @@ void EvalState::addPrimOps()
addPrimOp("abort", 1, primAbort);
addPrimOp("__head", 1, primHead);
addPrimOp("__tail", 1, primTail);
addPrimOp("__getEnv", 1, primGetEnv);
addPrimOp("map", 2, primMap);
addPrimOp("__getAttr", 2, primGetAttr);

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@ -1,5 +1,7 @@
source common.sh
export TEST_VAR=foo # for eval-okay-getenv.nix
fail=0
for i in lang/parse-fail-*.nix; do

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@ -0,0 +1 @@
Str("foobar")

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@ -0,0 +1 @@
builtins.getEnv "TEST_VAR" + (if builtins.getEnv "NO_SUCH_VAR" == "" then "bar" else "bla")