Add std::process::Command::envs()

Command::envs() adds a vector of key-value pairs to the child
process environment all at once.  Suggested in #38526.

1 files changed, 60 insertions, 0 deletions

diff --git a/src/test/run-pass/process-envs.rs b/src/test/run-pass/process-envs.rs
new file mode 100644
index 00000000000..229f8488f19
--- /dev/null
+++ b/src/test/run-pass/process-envs.rs
@@ -0,0 +1,60 @@
+// Copyright 2014, 2017 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+// ignore-emscripten
+
+use std::process::Command;
+use std::env;
+
+#[cfg(all(unix, not(target_os="android")))]
+pub fn env_cmd() -> Command {
+    Command::new("env")
+}
+#[cfg(target_os="android")]
+pub fn env_cmd() -> Command {
+    let mut cmd = Command::new("/system/bin/sh");
+    cmd.arg("-c").arg("set");
+    cmd
+}
+
+#[cfg(windows)]
+pub fn env_cmd() -> Command {
+    let mut cmd = Command::new("cmd");
+    cmd.arg("/c").arg("set");
+    cmd
+}
+
+fn main() {
+    // save original environment
+    let old_env = env::var_os("RUN_TEST_NEW_ENV");
+
+    env::set_var("RUN_TEST_NEW_ENV", "123");
+
+    // create filtered environment vector
+    let filtered_env : Vec<(String, String)> =
+        env::vars().filter(|&(ref k, _)| k == "PATH").collect();
+
+    let mut cmd = env_cmd()
+        .env_clear()
+        .envs(&filtered_env);
+
+    // restore original environment
+    match old_env {
+        None => env::remove_var("RUN_TEST_NEW_ENV"),
+        Some(val) => env::set_var("RUN_TEST_NEW_ENV", &val)
+    }
+
+    let prog = cmd.spawn().unwrap();
+    let result = prog.wait_with_output().unwrap();
+    let output = String::from_utf8_lossy(&result.stdout);
+
+    assert!(!output.contains("RUN_TEST_NEW_ENV"),
+            "found RUN_TEST_NEW_ENV inside of:\n\n{}", output);
+}