Add setenv to standard library

Author: brson

src/lib/generic_os.rs

@@ -1,8 +1,54 @@
+import str::sbuf;
 
 
+#[cfg(target_os = "linux")]
+#[cfg(target_os = "macos")]
 fn getenv(str n) -> option::t[str] {
     auto s = os::libc::getenv(str::buf(n));
     ret if (s as int == 0) {
             option::none[str]
         } else { option::some[str](str::str_from_cstr(s)) };
-}
+}
+
+#[cfg(target_os = "linux")]
+#[cfg(target_os = "macos")]
+fn setenv(str n, str v) {
+    auto nbuf = str::buf(n);
+    auto vbuf = str::buf(v);
+    os::libc::setenv(nbuf, vbuf, 1);
+}
+
+#[cfg(target_os = "win32")]
+fn getenv(str n) -> option::t[str]{
+    auto nbuf = str::buf(n);
+    auto nsize = 256u;
+    while (true) {
+        auto vstr = str::alloc(nsize - 1u);
+        auto vbuf = str::buf(vstr);
+        auto res = os::kernel32::GetEnvironmentVariableA(nbuf, vbuf, nsize);
+        if (res == 0u) {
+            ret option::none;
+        } else if (res < nsize) {
+            ret option::some(str::str_from_cstr(vbuf));
+        } else {
+            nsize = res;
+        }
+    }
+    fail;
+}
+
+#[cfg(target_os = "win32")]
+fn setenv(str n, str v) {
+    auto nbuf = str::buf(n);
+    auto vbuf = str::buf(v);
+    os::kernel32::SetEnvironmentVariableA(nbuf, vbuf);
+}
+
+// Local Variables:
+// mode: rust;
+// fill-column: 78;
+// indent-tabs-mode: nil
+// c-basic-offset: 4
+// buffer-file-coding-system: utf-8-unix
+// compile-command: "make -k -C .. 2>&1 | sed -e 's/\\/x\\//x:\\//g'";
+// End:

src/lib/win32_os.rs

@@ -18,7 +18,6 @@ native "cdecl" mod libc = "" {
     fn fwrite(vbuf buf, uint size, uint n, FILE f) -> uint;
     fn fseek(FILE f, int offset, int whence) -> int;
     fn ftell(FILE f) -> int;
-    fn getenv(sbuf n) -> sbuf;
     fn _pipe(*mutable int fds, uint size, int mode) -> int;
 }
 
@@ -49,6 +48,11 @@ mod libc_constants {
     }
 }
 
+native "x86stdcall" mod kernel32 {
+    fn GetEnvironmentVariableA(sbuf n, sbuf v, uint nsize) -> uint;
+    fn SetEnvironmentVariableA(sbuf n, sbuf v) -> int;
+}
+
 fn exec_suffix() -> str { ret ".exe"; }
 
 fn target_os() -> str { ret "win32"; }

src/test/run-pass/lib-os.rs

@@ -0,0 +1,49 @@
+// xfail-stage0
+
+use std;
+
+import std::generic_os::setenv;
+import std::generic_os::getenv;
+import std::option;
+
+#[test]
+fn test_setenv() {
+    setenv("NAME", "VALUE");
+    assert getenv("NAME") == option::some("VALUE");
+}
+
+#[test]
+fn test_setenv_overwrite() {
+    setenv("NAME", "1");
+    setenv("NAME", "2");
+    assert getenv("NAME") == option::some("2");
+}
+
+// Windows GetEnvironmentVariable requires some extra work to make sure
+// the buffer the variable is copied into is the right size
+#[test]
+fn test_getenv_big() {
+    auto s = "";
+    auto i = 0;
+    while (i < 100) {
+        s += "aaaaaaaaaa";
+        i += 1;
+    }
+    setenv("NAME", s);
+    assert getenv("NAME") == option::some(s);
+}
+
+fn main() {
+    test_setenv();
+    test_setenv_overwrite();
+    test_getenv_big();
+}
+
+// Local Variables:
+// mode: rust;
+// fill-column: 78;
+// indent-tabs-mode: nil
+// c-basic-offset: 4
+// buffer-file-coding-system: utf-8-unix
+// compile-command: "make -k -C .. 2>&1 | sed -e 's/\\/x\\//x:\\//g'";
+// End: