1 files changed, 52 insertions, 0 deletions
diff --git a/unix/utils/get_username.c b/unix/utils/get_username.c
new file mode 100644
index 00000000..61e259c0
--- /dev/null
+++ b/unix/utils/get_username.c
@@ -0,0 +1,52 @@
+/*
+ * Implementation of get_username() for Unix.
+ */
+
+#include <unistd.h>
+#include <pwd.h>
+
+#include "putty.h"
+
+char *get_username(void)
+{
+    struct passwd *p;
+    uid_t uid = getuid();
+    char *user, *ret = NULL;
+
+    /*
+     * First, find who we think we are using getlogin. If this
+     * agrees with our uid, we'll go along with it. This should
+     * allow sharing of uids between several login names whilst
+     * coping correctly with people who have su'ed.
+     */
+    user = getlogin();
+#if HAVE_SETPWENT
+    setpwent();
+#endif
+    if (user)
+        p = getpwnam(user);
+    else
+        p = NULL;
+    if (p && p->pw_uid == uid) {
+        /*
+         * The result of getlogin() really does correspond to
+         * our uid. Fine.
+         */
+        ret = user;
+    } else {
+        /*
+         * If that didn't work, for whatever reason, we'll do
+         * the simpler version: look up our uid in the password
+         * file and map it straight to a name.
+         */
+        p = getpwuid(uid);
+        if (!p)
+            return NULL;
+        ret = p->pw_name;
+    }
+#if HAVE_ENDPWENT
+    endpwent();
+#endif
+
+    return dupstr(ret);
+}