From f66724c99a322ec147b0297cba4334c589883b47 Mon Sep 17 00:00:00 2001
From: Stefan Weil <weil@mail.berlios.de>
Date: Thu, 15 Jul 2010 22:28:02 +0200
Subject: [PATCH] Add new user mode option -ignore-environment

An empty environment is sometimes useful in user mode.
The new option provides it for linux-user and bsd-user
(darwin-user still has no environment related options).

The patch also adds the documentation for other
environment related options.

Signed-off-by: Stefan Weil <weil@mail.berlios.de>
---
 bsd-user/main.c   |  6 ++++++
 linux-user/main.c |  6 ++++++
 qemu-doc.texi     | 14 ++++++++++++++
 3 files changed, 26 insertions(+)

diff --git a/bsd-user/main.c b/bsd-user/main.c
index aff9f13b18..6b12f8bba1 100644
--- a/bsd-user/main.c
+++ b/bsd-user/main.c
@@ -795,6 +795,12 @@ int main(int argc, char **argv)
             r = argv[optind++];
             if (envlist_setenv(envlist, r) != 0)
                 usage();
+        } else if (!strcmp(r, "ignore-environment")) {
+            envlist_free(envlist);
+            if ((envlist = envlist_create()) == NULL) {
+                (void) fprintf(stderr, "Unable to allocate envlist\n");
+                exit(1);
+            }
         } else if (!strcmp(r, "U")) {
             r = argv[optind++];
             if (envlist_unsetenv(envlist, r) != 0)
diff --git a/linux-user/main.c b/linux-user/main.c
index 69d050f91b..dbba8befe7 100644
--- a/linux-user/main.c
+++ b/linux-user/main.c
@@ -2790,6 +2790,12 @@ int main(int argc, char **argv, char **envp)
             r = argv[optind++];
             if (envlist_setenv(envlist, r) != 0)
                 usage();
+        } else if (!strcmp(r, "ignore-environment")) {
+            envlist_free(envlist);
+            if ((envlist = envlist_create()) == NULL) {
+                (void) fprintf(stderr, "Unable to allocate envlist\n");
+                exit(1);
+            }
         } else if (!strcmp(r, "U")) {
             r = argv[optind++];
             if (envlist_unsetenv(envlist, r) != 0)
diff --git a/qemu-doc.texi b/qemu-doc.texi
index d7d760fedd..c3765293d3 100644
--- a/qemu-doc.texi
+++ b/qemu-doc.texi
@@ -2186,6 +2186,13 @@ Set the x86 elf interpreter prefix (default=/usr/local/qemu-i386)
 Set the x86 stack size in bytes (default=524288)
 @item -cpu model
 Select CPU model (-cpu ? for list and additional feature selection)
+@item -ignore-environment
+Start with an empty environment. Without this option,
+the inital environment is a copy of the caller's environment.
+@item -E @var{var}=@var{value}
+Set environment @var{var} to @var{value}.
+@item -U @var{var}
+Remove @var{var} from the environment.
 @item -B offset
 Offset guest address by the specified number of bytes.  This is useful when
 the address region required by guest applications is reserved on the host.
@@ -2409,6 +2416,13 @@ Print the help
 Set the library root path (default=/)
 @item -s size
 Set the stack size in bytes (default=524288)
+@item -ignore-environment
+Start with an empty environment. Without this option,
+the inital environment is a copy of the caller's environment.
+@item -E @var{var}=@var{value}
+Set environment @var{var} to @var{value}.
+@item -U @var{var}
+Remove @var{var} from the environment.
 @item -bsd type
 Set the type of the emulated BSD Operating system. Valid values are
 FreeBSD, NetBSD and OpenBSD (default).