[OE-core] [PATCH 1/1 V2] runqemu-gen-tapdevs: Allow run --help without sudo

[Robert Yang]

Then we can get user's UID and GID rather than hardcode to 1000, e.g.:

- Without sudo
$ runqemu-gen-tapdevs --help
[snip]
$ sudo ../poky/scripts/runqemu-gen-tapdevs 15220 100 4 tmp/sysroots-components/x86_64/qemu-helper-native/usr/bin
[snip]

- With sudo
$ sudo ../poky/scripts/runqemu-gen-tapdevs --help
[snip]
$ sudo ../poky/scripts/runqemu-gen-tapdevs 15220 100 4 tmp/sysroots-components/x86_64/qemu-helper-native/usr/bin
[snip]

Signed-off-by: Robert Yang <liezhi.yang at windriver.com>
---
 scripts/runqemu-gen-tapdevs | 27 +++++++++++++++++++--------
 1 file changed, 19 insertions(+), 8 deletions(-)

diff --git a/scripts/runqemu-gen-tapdevs b/scripts/runqemu-gen-tapdevs
index 11de318..869fee2 100755
--- a/scripts/runqemu-gen-tapdevs
+++ b/scripts/runqemu-gen-tapdevs
@@ -22,22 +22,28 @@
 # with this program; if not, write to the Free Software Foundation, Inc.,
 # 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 
+uid=`id -u`
+gid=`id -g`
+if [ -n "$SUDO_UID" ]; then
+    uid=$SUDO_UID
+fi
+if [ -n "$SUDO_GID" ]; then
+    gid=$SUDO_GID
+fi
+
 usage() {
 	echo "Usage: sudo $0 <uid> <gid> <num> <staging_bindir_native>"
-        echo "Where <uid> is the numeric user id the tap devices will be owned by"
+	echo "Where <uid> is the numeric user id the tap devices will be owned by"
 	echo "Where <gid> is the numeric group id the tap devices will be owned by"
 	echo "<num> is the number of tap devices to create (0 to remove all)"
 	echo "<native-sysroot-basedir> is the path to the build system's native sysroot"
-	echo "e.g. $ bitbake qemu-helper-native"
-	echo "$ sudo $0 1000 1000 4 tmp/sysroots-components/x86_64/qemu-helper-native/usr/bin"
+	echo "For example:"
+	echo "$ bitbake qemu-helper-native"
+	echo "$ sudo $0 $uid $gid 4 tmp/sysroots-components/x86_64/qemu-helper-native/usr/bin"
+	echo ""
 	exit 1
 }
 
-if [ $EUID -ne 0 ]; then
-	echo "Error: This script must be run with root privileges"
-	exit
-fi
-
 if [ $# -ne 4 ]; then
 	echo "Error: Incorrect number of arguments"
 	usage
@@ -54,6 +60,11 @@ if [[ ! -x "$TUNCTL" || -d "$TUNCTL" ]]; then
 	usage
 fi
 
+if [ $EUID -ne 0 ]; then
+	echo "Error: This script must be run with root privileges"
+	exit
+fi
+
 SCRIPT_DIR=`dirname $0`
 RUNQEMU_IFUP="$SCRIPT_DIR/runqemu-ifup"
 if [ ! -x "$RUNQEMU_IFUP" ]; then
-- 
2.10.2