Rendering学習日記

# yum groupinstall "Development Tools"

# uname -a
Linux localhost.localdomain 2.6.32-754.28.1.el6.x86_64 #1 SMP Wed Mar 11 18:38:45 UTC 2020 x86_64 x86_64 x86_64 GNU/Linux

python-devel

# yum install python-devel

freeglut

# yum install freeglut
# yum install freeglut-devel
Installed:
freeglut-devel.x86_64 0:2.6.0-1.el6
Dependency Installed:
libX11-devel.x86_64 0:1.6.4-3.el6
libXau-devel.x86_64 0:1.0.6-4.el6
libXdamage-devel.x86_64 0:1.1.3-4.el6
libXext-devel.x86_64 0:1.3.3-1.el6
libXfixes-devel.x86_64 0:5.0.3-1.el6
libXxf86vm-devel.x86_64 0:1.1.3-2.1.el6
libdrm-devel.x86_64 0:2.4.65-2.el6
libxcb-devel.x86_64 0:1.12-4.el6
mesa-libGL-devel.x86_64 0:11.0.7-4.el6
mesa-libGLU-devel.x86_64 0:11.0.7-4.el6
xorg-x11-proto-devel.noarch 0:7.7-14.el6

PIL1.17, PyOpenGL, scons, ..etc..

# yum install python-imaging
# yum install PyOpenGL
# yum install scons
# yum install glibc-static
Installed:
glibc-static.x86_64 0:2.12-1.212.el6_10.3
# yum install compat-libstdc++-33-3.2.3-69.el6.x86_64

pygame

https://download-ib01.fedoraproject.org/pub/epel/6/x86_64/Packages/p/pygame-1.9.1-4.el6.x86_64.rpm
# rpm -Uvh pygame-1.9.1-4.el6.x86_64.rpm
warning: pygame-1.9.1-4.el6.x86_64.rpm: Header V3 RSA/SHA256 Signature, key ID 0608b895: NOKEY
error: Failed dependencies:
libSDL_image-1.2.so.0()(64bit) is needed by pygame-1.9.1-4.el6.x86_64
libSDL_mixer-1.2.so.0()(64bit) is needed by pygame-1.9.1-4.el6.x86_64
libSDL_ttf-2.0.so.0()(64bit) is needed by pygame-1.9.1-4.el6.x86_64
libportmidi.so.0()(64bit) is needed by pygame-1.9.1-4.el6.x86_6

https://download-ib01.fedoraproject.org/pub/epel/6/x86_64/Packages/s/SDL_image-1.2.12-9.el6.x86_64.rpm
# rpm -Uvh SDL_image-1.2.12-9.el6.x86_64.rpm
warning: SDL_image-1.2.12-9.el6.x86_64.rpm: Header V3 RSA/SHA256 Signature, key ID 0608b895: NOKEY
Preparing... ########################################### [100%]
1:SDL_image ########################################### [100%]

https://download-ib01.fedoraproject.org/pub/epel/6/x86_64/Packages/s/SDL_mixer-1.2.12-1.el6.x86_64.rpm
# rpm -Uvh SDL_mixer-1.2.12-1.el6.x86_64.rpm
warning: SDL_mixer-1.2.12-1.el6.x86_64.rpm: Header V3 RSA/SHA256 Signature, key ID 0608b895: NOKEY
Preparing... ########################################### [100%]
1:SDL_mixer ########################################### [100%]

https://download-ib01.fedoraproject.org/pub/epel/6/x86_64/Packages/s/SDL_ttf-2.0.11-6.el6.x86_64.rpm
# rpm -Uvh SDL_ttf-2.0.11-6.el6.x86_64.rpm
warning: SDL_ttf-2.0.11-6.el6.x86_64.rpm: Header V3 RSA/SHA256 Signature, key ID 0608b895: NOKEY
Preparing... ########################################### [100%]
1:SDL_ttf ########################################### [100%]

https://download-ib01.fedoraproject.org/pub/epel/6/x86_64/Packages/p/portmidi-217-3.el6.x86_64.rpm
rpm -Uvh portmidi-217-3.el6.x86_64.rpm
warning: portmidi-217-3.el6.x86_64.rpm: Header V3 RSA/SHA256 Signature, key ID 0608b895: NOKEY
Preparing... ########################################### [100%]
1:portmidi ########################################### [100%]

# rpm -Uvh pygame-1.9.1-4.el6.x86_64.rpm
warning: pygame-1.9.1-4.el6.x86_64.rpm: Header V3 RSA/SHA256 Signature, key ID 0608b895: NOKEY
Preparing... ########################################### [100%]
1:pygame ########################################### [100%]

PyProtocols-0.9.3

# python setup.py --without-speedups install

boost-devel

# yum install boost-devel-1.41.0-28.el6.x86_64
Installed:
boost-devel.x86_64 0:1.41.0-28.el6
Dependency Installed:
boost.x86_64 0:1.41.0-28.el6
boost-date-time.x86_64 0:1.41.0-28.el6
boost-graph.x86_64 0:1.41.0-28.el6
boost-iostreams.x86_64 0:1.41.0-28.el6
boost-math.x86_64 0:1.41.0-28.el6
boost-python.x86_64 0:1.41.0-28.el6
boost-regex.x86_64 0:1.41.0-28.el6
boost-serialization.x86_64 0:1.41.0-28.el6
boost-signals.x86_64 0:1.41.0-28.el6
boost-test.x86_64 0:1.41.0-28.el6
boost-thread.x86_64 0:1.41.0-28.el6
boost-wave.x86_64 0:1.41.0-28.el6

ode ode-devel

not ode.i686 but ode.x86_64.
http://rpm.pbone.net/index.php3/stat/3/srodzaj/1/search/ode-devel
ftp://ftp.pbone.net/mirror/archive.fedoraproject.org/epel/5/x86_64/ode-0.11.1-4.el5.x86_64.rpm
ftp://ftp.pbone.net/mirror/archive.fedoraproject.org/epel/5/x86_64/ode-devel-0.11.1-4.el5.x86_64.rpm

Pyrex

http://mirror.centos.org/centos/6/os/i386/Packages/Pyrex-0.9.8.4-4.1.el6.noarch.rpm
# rpm -Uvh Pyrex-0.9.8.4-4.1.el6.noarch.rpm
Preparing... ########################################### [100%]
1:Pyrex ########################################### [100%]

Download:PyODE

http://pyode.sourceforge.net/#download
# python setup.py build
# python setup.py install

Download:Pyserials

http://pypi.python.org/pypi/pyserial
pyserial-2.6.tar.gz

https://files.pythonhosted.org/packages/fb/93/e350757db177234e77037dbbbf8551c0a6e43b634f375590399fef920fde/pyserial-2.6.tar.gz

# python setup.py install

Download:cgkit

$ python checkenv.py
----------------------------------------------------------------------
Python 2.6.6 (r266:84292, Jun 20 2019, 14:14:55)
[GCC 4.4.7 20120313 (Red Hat 4.4.7-23)]
Platform: linux2
----------------------------------------------------------------------
Python version: 2.6........... OK
PyProtocols................... is installed
PyOpenGL...................... is installed
PIL........................... is installed
pygame........................ is installed
PyODE......................... missing

The Python bindings of the Open Dynamics Engine (ODE) are not installed.
You will not be able to use the ODEDynamics component to do rigid body
simulations. You can get PyODE at http://pyode.sourceforge.net/

PySerial...................... missing

PySerial is not installed. This module is only required for accessing
an Ascension Flock Of Bird motion tracker. You can get the module at
http://pyserial.sourceforge.net/

cgkit (base).................. missing
cgkit (C++ lib)............... failed

The cgkit supportlib could not be imported. One possible reason for that
is that shared libraries (such as the boost_python runtime or OpenGL)
could not be found.

cgkit (all)................... failed

lib3ds lib3ds-devel

https://download-ib01.fedoraproject.org/pub/epel/6/x86_64/Packages/l/lib3ds-1.3.0-9.el6.x86_64.rpm
http://rpmfind.net/linux/RPM/dag/redhat/el6/x86_64/lib3ds-1.2.0-1.el6.rf.x86_64.html
-------------------------
https://download-ib01.fedoraproject.org/pub/epel/6/x86_64/Packages/l/lib3ds-devel-1.3.0-9.el6.x86_64.rpm
-------------------------

# rpm -Uvh lib3ds-1.3.0-9.el6.x86_64.rpm
warning: lib3ds-1.3.0-9.el6.x86_64.rpm: Header V3 RSA/SHA256 Signature, key ID 0608b895: NOKEY
Preparing... ########################################### [100%]
1:lib3ds ########################################### [100%]
[root@localhost Downloads]# rpm -Uvh lib3ds-devel-1.3.0-9.el6.x86_64.rpm
warning: lib3ds-devel-1.3.0-9.el6.x86_64.rpm: Header V3 RSA/SHA256 Signature, key ID 0608b895: NOKEY
Preparing... ########################################### [100%]
1:lib3ds-devel ########################################### [100%]

config.cfg

config_template.cfg in cgkit2.0.0 folder
rename config.cfg

####### Libd3DS #######

LIB3DS_AVAILABLE = True
LIB3DS_PATH = r"/usr/lib64"
LIB3DS_LIBNAME = "lib3ds"

Error case1: cgkit 3ds import plugin

following are: build error
/usr/bin/ld: cannot find -llib3ds
collect2: ld returned 1 exit status
error: command 'g++' failed with exit status 1


g++ -pthread -shared build/temp.linux-x86_64-2.6/wrappers/py_wrapper.o build/temp.linux-x86_64-2.6/wrappers/py_noise.o build/temp.linux-x86_64-2.6/wrappers/py_vec3.o build/temp.linux-x86_64-2.6/wrappers/py_vec4.o build/temp.linux-x86_64-2.6/wrappers/py_mat3.o build/temp.linux-x86_64-2.6/wrappers/py_mat4.o build/temp.linux-x86_64-2.6/wrappers/py_quat.o build/temp.linux-x86_64-2.6/wrappers/py_slots1.o build/temp.linux-x86_64-2.6/wrappers/py_slots2.o build/temp.linux-x86_64-2.6/wrappers/py_slots3.o build/temp.linux-x86_64-2.6/wrappers/py_slots4.o build/temp.linux-x86_64-2.6/wrappers/py_arrayslots1.o build/temp.linux-x86_64-2.6/wrappers/py_arrayslots2.o build/temp.linux-x86_64-2.6/wrappers/py_arrayslot_mat3.o build/temp.linux-x86_64-2.6/wrappers/py_arrayslot_mat4.o build/temp.linux-x86_64-2.6/wrappers/py_arrayslots4.o build/temp.linux-x86_64-2.6/wrappers/py_component.o build/temp.linux-x86_64-2.6/wrappers/py_boundingbox.o build/temp.linux-x86_64-2.6/wrappers/py_worldobject.o build/temp.linux-x86_64-2.6/wrappers/py_worldobject2.o build/temp.linux-x86_64-2.6/wrappers/py_worldobject3.o build/temp.linux-x86_64-2.6/wrappers/py_material.o build/temp.linux-x86_64-2.6/wrappers/py_glmaterial.o build/temp.linux-x86_64-2.6/wrappers/py_geoms1.o build/temp.linux-x86_64-2.6/wrappers/py_spheregeom.o build/temp.linux-x86_64-2.6/wrappers/py_ccylindergeom.o build/temp.linux-x86_64-2.6/wrappers/py_torusgeom.o build/temp.linux-x86_64-2.6/wrappers/py_boxgeom.o build/temp.linux-x86_64-2.6/wrappers/py_planegeom.o build/temp.linux-x86_64-2.6/wrappers/py_trimeshgeom.o build/temp.linux-x86_64-2.6/wrappers/py_polyhedrongeom.o build/temp.linux-x86_64-2.6/wrappers/py_drawgeom.o build/temp.linux-x86_64-2.6/wrappers/py_lightsource.o build/temp.linux-x86_64-2.6/wrappers/py_glpointlight.o build/temp.linux-x86_64-2.6/wrappers/py_glspotlight.o build/temp.linux-x86_64-2.6/wrappers/py_gldistantlight.o build/temp.linux-x86_64-2.6/wrappers/py_glrenderer.o build/temp.linux-x86_64-2.6/wrappers/py_massproperties.o build/temp.linux-x86_64-2.6/wrappers/rply/rply/rply.o build/temp.linux-x86_64-2.6/wrappers/rply/py_rply_read.o build/temp.linux-x86_64-2.6/wrappers/rply/py_rply_write.o build/temp.linux-x86_64-2.6/wrappers/lib3ds/common_funcs.o build/temp.linux-x86_64-2.6/wrappers/lib3ds/nodedata.o build/temp.linux-x86_64-2.6/wrappers/lib3ds/light.o build/temp.linux-x86_64-2.6/wrappers/lib3ds/mesh.o build/temp.linux-x86_64-2.6/wrappers/lib3ds/material.o build/temp.linux-x86_64-2.6/wrappers/lib3ds/lib3ds.o -Lsupportlib/lib -L/usr/lib64 -lboost_python -lcore /usr/lib64/lib3ds.a -lGL -lGLU -lpython2.6 -o build/lib.linux-x86_64-2.6/cgkit/_core.so

/usr/bin/ld: /usr/lib64/lib3ds.a(file.o): relocation R_X86_64_32 against `.rodata.str1.1' can not be used when making a shared object; recompile with -fPIC
/usr/lib64/lib3ds.a: could not read symbols: Bad value
collect2: ld returned 1 exit status

Error case2: cgkit 3ds import plugin

####### Libd3DS #######

LIB3DS_AVAILABLE = True
LIB3DS_PATH = r"/usr/lib64"
LIB3DS_LIBNAME = "lib3ds"

# ldconfig

lib64]# ls -l lib3ds*
lrwxrwxrwx. 1 root root 17 May 1 20:14 lib3ds-1.so.3 -> lib3ds-1.so.3.0.0
-rwxr-xr-x. 1 root root 123688 Sep 15 2010 lib3ds-1.so.3.0.0
lrwxrwxrwx. 1 root root 17 May 1 20:14 lib3ds.so -> lib3ds-1.so.3.0.0

# ldconfig -p | grep lib3ds
lib3ds-1.so.3 (libc6,x86-64) => /usr/lib64/lib3ds-1.so.3

# ln -s /usr/lib64/lib3ds-1.so.3 /usr/lib64/lib3ds.so

[root@localhost cgkit-2.0.0]# ldconfig -p | grep lib3ds
lib3ds-1.so.3 (libc6,x86-64) => /usr/lib64/lib3ds-1.so.3
[root@localhost cgkit-2.0.0]# ln -s /usr/lib64/lib3ds-1.so.3 /usr/lib64/lib3ds.so
ln: creating symbolic link `/usr/lib64/lib3ds.so': File exists

cgkit 3ds import plugin

changed config.cfg

---------------------------
####### Libd3DS #######
LIB3DS_AVAILABLE = True
LIB3DS_PATH = r"/usr/lib64/lib3ds.so"
#LIB3DS_LIBNAME = "3ds"
----------------------------
# python setup.py build

g++ -pthread -shared build/temp.linux-x86_64-2.6/wrappers/py_wrapper.o build/temp.linux-x86_64-2.6/wrappers/py_noise.o build/temp.linux-x86_64-2.6/wrappers/py_vec3.o build/temp.linux-x86_64-2.6/wrappers/py_vec4.o build/temp.linux-x86_64-2.6/wrappers/py_mat3.o build/temp.linux-x86_64-2.6/wrappers/py_mat4.o build/temp.linux-x86_64-2.6/wrappers/py_quat.o build/temp.linux-x86_64-2.6/wrappers/py_slots1.o build/temp.linux-x86_64-2.6/wrappers/py_slots2.o build/temp.linux-x86_64-2.6/wrappers/py_slots3.o build/temp.linux-x86_64-2.6/wrappers/py_slots4.o build/temp.linux-x86_64-2.6/wrappers/py_arrayslots1.o build/temp.linux-x86_64-2.6/wrappers/py_arrayslots2.o build/temp.linux-x86_64-2.6/wrappers/py_arrayslot_mat3.o build/temp.linux-x86_64-2.6/wrappers/py_arrayslot_mat4.o build/temp.linux-x86_64-2.6/wrappers/py_arrayslots4.o build/temp.linux-x86_64-2.6/wrappers/py_component.o build/temp.linux-x86_64-2.6/wrappers/py_boundingbox.o build/temp.linux-x86_64-2.6/wrappers/py_worldobject.o build/temp.linux-x86_64-2.6/wrappers/py_worldobject2.o build/temp.linux-x86_64-2.6/wrappers/py_worldobject3.o build/temp.linux-x86_64-2.6/wrappers/py_material.o build/temp.linux-x86_64-2.6/wrappers/py_glmaterial.o build/temp.linux-x86_64-2.6/wrappers/py_geoms1.o build/temp.linux-x86_64-2.6/wrappers/py_spheregeom.o build/temp.linux-x86_64-2.6/wrappers/py_ccylindergeom.o build/temp.linux-x86_64-2.6/wrappers/py_torusgeom.o build/temp.linux-x86_64-2.6/wrappers/py_boxgeom.o build/temp.linux-x86_64-2.6/wrappers/py_planegeom.o build/temp.linux-x86_64-2.6/wrappers/py_trimeshgeom.o build/temp.linux-x86_64-2.6/wrappers/py_polyhedrongeom.o build/temp.linux-x86_64-2.6/wrappers/py_drawgeom.o build/temp.linux-x86_64-2.6/wrappers/py_lightsource.o build/temp.linux-x86_64-2.6/wrappers/py_glpointlight.o build/temp.linux-x86_64-2.6/wrappers/py_glspotlight.o build/temp.linux-x86_64-2.6/wrappers/py_gldistantlight.o build/temp.linux-x86_64-2.6/wrappers/py_glrenderer.o build/temp.linux-x86_64-2.6/wrappers/py_massproperties.o build/temp.linux-x86_64-2.6/wrappers/rply/rply/rply.o build/temp.linux-x86_64-2.6/wrappers/rply/py_rply_read.o build/temp.linux-x86_64-2.6/wrappers/rply/py_rply_write.o build/temp.linux-x86_64-2.6/wrappers/lib3ds/common_funcs.o build/temp.linux-x86_64-2.6/wrappers/lib3ds/nodedata.o build/temp.linux-x86_64-2.6/wrappers/lib3ds/light.o build/temp.linux-x86_64-2.6/wrappers/lib3ds/mesh.o build/temp.linux-x86_64-2.6/wrappers/lib3ds/material.o build/temp.linux-x86_64-2.6/wrappers/lib3ds/lib3ds.o -Lsupportlib/lib -L/usr/lib64 -lboost_python -lcore -l3ds -lGL -lGLU -lpython2.6 -o build/lib.linux-x86_64-2.6/cgkit/_core.so

# python setup.py install

[@localhost utilities]$ python checkenv.py
----------------------------------------------------------------------
Python 2.6.6 (r266:84292, Jun 20 2019, 14:14:55)
[GCC 4.4.7 20120313 (Red Hat 4.4.7-23)]
Platform: linux2
----------------------------------------------------------------------
Python version: 2.6........... OK
PyProtocols................... is installed
PyOpenGL...................... is installed
PIL........................... is installed
pygame........................ is installed
PyODE......................... is installed
PySerial...................... is installed
cgkit (base).................. 2.0.0 (Apr 30 2020)
cgkit (C++ lib)............... OK
cgkit (all)................... OK

viewer.py bunny.3ds

$ render.py -rair bunny.3ds

Fedora 32 upgrade now.
after reboot.
but black screen.
for a while.

My laptop let power off.

power on.

GRUB bootloader to appear (the boot selection screen).
press the “e” key to edit.

Scroll down
The line should finally end with “rhgb” and “quiet”.
Remove “rhgb” and “quiet”, and then add “nomodeset=0”
Press “CTRL+x” to boot the system.
The system should now boot.

Installing starts.

Thank you.
https://www.stephenwagner.com/2018/08/25/fedora-core-black-screen-with-cursor-after-install-upgrade/

How to change default Python version on Linux/Fedora 32

under Fedora32

# alternatives --install /usr/bin/python python /usr/bin/python3.8 2
# alternatives --install /usr/bin/python python /usr/bin/python2.7 1

$ sudo alternatives --config python

2 プログラムがあり 'python' を提供します。

選択 コマンド
-----------------------------------------------
* 1 /usr/bin/python3.8
+ 2 /usr/bin/python2.7

Enter を押して現在の選択 [+] を保持するか、選択番号を入力します:1

$ alternatives --list | grep -i python
python manual /usr/bin/python3.8

boost python

can not find -lboost_python

-----------------------------------------------
Install boost
Install boost-devel
Install python2-devel
Install python3-devel
Install boost-python2
Install boost-python3
-----------------------------------------------

-Lsupportlib/lib -L/usr/lib64 -lboost_python -lcore -l3ds -lGL -lGLU -lpython2.7 -o build/lib.linux-x86_64-2.7/cgkit/_core.so
/usr/bin/ld: -lboost_python が見つかりません
collect2: エラー: ld はステータス 1 で終了しました

$ sudo ldconfig -p | grep boost_python3
libboost_python38.so.1.69.0 (libc6,x86-64) => /lib64/libboost_python38.so.1.69.0

$ sudo ldconfig -p | grep boost_python2
libboost_python27.so.1.69.0 (libc6,x86-64) => /lib64/libboost_python27.so.1.69.0

/usr/lib64
$ sudo ln -s libboost_python27.so.1.69.0 libboost_python2.so

/usr/lib64 $ sudo ldconfig
-lboost_python2 is OK.

Boost.Python の機能をざっと紹介してみる
http://moriyoshi.hatenablog.com/entry/20091214/1260779899

export CPLUS_INCLUDE_PATH=/usr/include/python2.7

$ python
Python 2.7.18 (default, Apr 20 2020, 00:00:00)
[GCC 10.0.1 20200328 (Red Hat 10.0.1-0.11)] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> exit()
$ export CPLUS_INCLUDE_PATH=/usr/include/python2.7
$ g++ -I`python -c 'from distutils.sysconfig import *; get_python_inc()'` -DPIC -shared -fPIC -o basic.so basic.cpp -lboost_python-py27
/usr/bin/ld: -lboost_python-py27 が見つかりません
collect2: エラー: ld はステータス 1 で終了しました

g++ -I`python -c 'from distutils.sysconfig import *; get_python_inc()'` -DPIC -shared -fPIC -o basic.so basic.cpp -lboost_python2

python cgkit install under fedora 32

switch python2.7
$ sudo alternatives --config python
[sudo] のパスワード:

3 プログラムがあり 'python' を提供します。

選択 コマンド
-----------------------------------------------
1 /usr/bin/python3.7
+ 2 /usr/bin/python2.7
* 3 /usr/bin/python3.8

Enter を押して現在の選択 [+] を保持するか、選択番号を入力します:
$ alternatives --list | grep -i python
python manual /usr/bin/python2.7
------------------------------------------------

/usr/lib64
$ sudo ln -s libboost_python27.so.1.69.0 libboost_python2.so
------------------------------------------------

python cgkit folder config.cfg
######################################################################
# Boost.Python settings
######################################################################

# Name of the Boost.Python library to link with
BOOST_LIB = "boost_python2"

######################################################################
# Optional libraries
######################################################################

Install lib3ds-devel

####### Libd3DS #######

LIB3DS_AVAILABLE = True
LIB3DS_PATH = r"/lib64/"
LIB3DS_LIBNAME = "3ds"
------------------------------------------------
$ sudo python setup.py build
.....
.....
.....
$ sudo python setup.py install
python cgkit is OK.

alternatives --remove python

$ sudo alternatives --config python
[sudo] のパスワード:

3 プログラムがあり 'python' を提供します。

選択 コマンド
-----------------------------------------------
1 /usr/bin/python3.7
+ 2 /usr/bin/python2.7
* 3 /usr/bin/python3.8

Enter を押して現在の選択 [+] を保持するか、選択番号を入力します:

$ sudo alternatives --remove python /usr/bin/python3.7

$ sudo alternatives --config python

2 プログラムがあり 'python' を提供します。

選択 コマンド
-----------------------------------------------
* 1 /usr/bin/python3.8
+ 2 /usr/bin/python2.7

Enter を押して現在の選択 [+] を保持するか、選択番号を入力します:
-----------------------------------------------------------
$ sudo alternatives --config python

2 プログラムがあり 'python' を提供します。

選択 コマンド
-----------------------------------------------
* 1 /usr/bin/python3.8
+ 2 /usr/bin/python2.7

Enter を押して現在の選択 [+] を保持するか、選択番号を入力します:1
~]$ python
Python 3.8.2 (default, Feb 28 2020, 00:00:00)
[GCC 10.0.1 20200216 (Red Hat 10.0.1-0.8)] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> exit()
~]$ sudo alternatives --config python

2 プログラムがあり 'python' を提供します。

選択 コマンド
-----------------------------------------------
*+ 1 /usr/bin/python3.8
2 /usr/bin/python2.7

Enter を押して現在の選択 [+] を保持するか、選択番号を入力します:2
~]$ python
Python 2.7.18 (default, Apr 20 2020, 00:00:00)
[GCC 10.0.1 20200328 (Red Hat 10.0.1-0.11)] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> exit()

Thank you.