구차니의 잡동사니 모음

segmentation fault는 주소 영역은 존재하는데 접근해서는 안되는 주소를 간거라고 한다면

bus error는 물리적 주소조차도 존재하지 않는 영역을 갈경우 발생하는건가?

[링크 : https://learntechway.com/difference-between-segmentation-fault-and-bus-error/]

잘 외워두고 써야겠군 

ifconfig eth0 192.168.1.123 netmask 255.255.255.0 up
route add default gw 192.168.1.1

[링크 : https://southlife.tistory.com/82]

udev는 장치관리자 / 자동 마운트지

user space driver 와는 연관이 없는 것 같은데....

user space driver 에 대한 마운트를 진행하기도 하니 그거랑 연관이 있다고 해야하나 말아야 하나..

[링크 : http://wiki.archlinux.org/index.php/Udev]

[링크 : http://lascrea.tistory.com/89]

user space driver를 보다가 점점 이상한데로 헤매는 느낌..

rtl-sdr에서 왜 자꾸 이상한데로 새는건가.. ㅠㅠ

[링크 : http://lethean.github.io/2006/12/19/uio-linux-userspace-kernel-driver/]

[링크 : http://www.kernel.org/doc/html/v4.14/driver-api/uio-howto.html]

네트워크 설정은 특색이라고 해야하나

redhat이나 debian 계열과는 또 확연히 다르다.

[링크 : https://continuetochallenge.tistory.com/40]

ssh 데몬을 활성화 하고

firewalld 에서 ssh를 허용해주어야 한다.

[링크 : https://continuetochallenge.tistory.com/38]

야이 강아지들이 하나로 좀 통일해라 ㅠㅠㅠㅠ

[링크 : https://www.cyberciti.biz/faq/how-to-install-htop-on-opensuse-linux-using-zypper/]

그나저나 cnf는 무슨 유틸리티 인건가..

엌... command not found 줄여서 cnf ㅋㅋㅋㅋㅋ 핸들러!!

COMMAND-NOT-FOUND(1)      http://en.opensuse.org/Sco      COMMAND-NOT-FOUND(1)

NAME
       command-not-found - A command-not-found handler

SYNOPSIS
       command-not-found {binary_name} {repository}

예전에 겪었던 건데 일단 이유만 말하자면

바이너리 파일은 32bit용

실행 환경은 64bit인데 32bit 호환용 라이브러리가 없어서 에러를 그따구로 내는 것!

[링크 : https://askubuntu.com/questions/133389/no-such-file-or-directory-but-the-file-exists]

[링크 : https://minimonk.tistory.com/6541]

apt list 명령어나

aptitude 패키지를 설치해서 해당 유틸리티로 확인하는게 가장 확실한 듯

[링크 : https://www.cyberciti.biz/faq/debian-ubuntu-linux-apt-get-aptitude-show-package-version-command/]

+

만약에 해당 버전 배포판에서 원하는 버전(그러니까 구버전)이 없으면 어떻게 해야하려나?

/etc/inittab이 안되서 찾아보니

systemctl set-default 명령을 통해서 바꾸면 된다.

# systemctl get-default
graphical.target

# systemctl set-default multi-user.target
Created symlink /etc/systemd/system/default.target → /usr/lib/systemd/system/multi-user.target.

# systemctl get-default
multi-user.target

# systemctl list-units -t target -a
  UNIT                      LOAD      ACTIVE   SUB    DESCRIPTION
  basic.target              loaded    active   active Basic System
  cryptsetup.target         loaded    active   active Local Encrypted Volumes
  emergency.target          loaded    inactive dead   Emergency Mode
  getty-pre.target          loaded    inactive dead   Login Prompts (Pre)
  getty.target              loaded    active   active Login Prompts
  graphical.target          loaded    inactive dead   Graphical Interface
  initrd-fs.target          loaded    inactive dead   Initrd File Systems
  initrd-root-device.target loaded    inactive dead   Initrd Root Device
  initrd-root-fs.target     loaded    inactive dead   Initrd Root File System
  initrd-switch-root.target loaded    inactive dead   Switch Root
  initrd.target             loaded    inactive dead   Initrd Default Target
  local-fs-pre.target       loaded    active   active Local File Systems (Pre)
  local-fs.target           loaded    active   active Local File Systems
  multi-user.target         loaded    active   active Multi-User System
  network-online.target     loaded    active   active Network is Online
  network-pre.target        loaded    active   active Network (Pre)
  network.target            loaded    active   active Network
  nfs-client.target         loaded    active   active NFS client services
  nss-lookup.target         loaded    inactive dead   Host and Network Name Lookups
  nss-user-lookup.target    loaded    active   active User and Group Name Lookups
  paths.target              loaded    active   active Paths
  remote-fs-pre.target      loaded    active   active Remote File Systems (Pre)
  remote-fs.target          loaded    active   active Remote File Systems
  rescue.target             loaded    inactive dead   Rescue Mode
  rpc_pipefs.target         loaded    active   active rpc_pipefs.target
  rpcbind.target            loaded    active   active RPC Port Mapper
  shutdown.target           loaded    inactive dead   Shutdown
  slices.target             loaded    active   active Slices
  sockets.target            loaded    active   active Sockets
  sound.target              loaded    active   active Sound Card
  sshd-keygen.target        loaded    active   active sshd-keygen.target
  swap.target               loaded    active   active Swap
  sysinit.target            loaded    active   active System Initialization
● syslog.target             not-found inactive dead   syslog.target
  time-sync.target          loaded    inactive dead   System Time Synchronized
  timers.target             loaded    active   active Timers
  umount.target             loaded    inactive dead   Unmount All Filesystems

LOAD   = Reflects whether the unit definition was properly loaded.
ACTIVE = The high-level unit activation state, i.e. generalization of SUB.
SUB    = The low-level unit activation state, values depend on unit type.

37 loaded units listed.
To show all installed unit files use 'systemctl list-unit-files'.

[링크 : https://www.linuxfork.com/how-to-change-the-run-level-on-rhel-centos-7-8/]

+

아래는 안되는 왜 한지 모르겠는 뻘짓

--force를 주고도 한번에 안되서 여러번을 하고 나서야 되네..

stop 하고 나서 된건진 잘 모르겠다.

그리고 여전히 gui로 켜지는건 달라지지 않았다 ㅠㅠ

]# systemctl list-units -t target -a
  UNIT                      LOAD      ACTIVE   SUB    DESCRIPTION
  basic.target              loaded    active   active Basic System
  cryptsetup.target         loaded    active   active Local Encrypted Volumes
  emergency.target          loaded    inactive dead   Emergency Mode
  getty-pre.target          loaded    inactive dead   Login Prompts (Pre)
  getty.target              loaded    active   active Login Prompts
  graphical.target          loaded    active   active Graphical Interface
  initrd-fs.target          loaded    inactive dead   Initrd File Systems
  initrd-root-device.target loaded    inactive dead   Initrd Root Device
  initrd-root-fs.target     loaded    inactive dead   Initrd Root File System
  initrd-switch-root.target loaded    inactive dead   Switch Root
  initrd.target             loaded    inactive dead   Initrd Default Target
  local-fs-pre.target       loaded    active   active Local File Systems (Pre)
  local-fs.target           loaded    active   active Local File Systems
  multi-user.target         loaded    active   active Multi-User System
  network-online.target     loaded    active   active Network is Online
  network-pre.target        loaded    active   active Network (Pre)
  network.target            loaded    active   active Network
  nfs-client.target         loaded    active   active NFS client services
  nss-lookup.target         loaded    inactive dead   Host and Network Name Lookups
  nss-user-lookup.target    loaded    active   active User and Group Name Lookups
  paths.target              loaded    active   active Paths
  remote-fs-pre.target      loaded    active   active Remote File Systems (Pre)
  remote-fs.target          loaded    active   active Remote File Systems
  rescue.target             loaded    inactive dead   Rescue Mode
  rpc_pipefs.target         loaded    active   active rpc_pipefs.target
  rpcbind.target            loaded    active   active RPC Port Mapper
  shutdown.target           loaded    inactive dead   Shutdown
  slices.target             loaded    active   active Slices
  sockets.target            loaded    active   active Sockets
  sound.target              loaded    active   active Sound Card
  sshd-keygen.target        loaded    active   active sshd-keygen.target
  swap.target               loaded    active   active Swap
  sysinit.target            loaded    active   active System Initialization
● syslog.target             not-found inactive dead   syslog.target
  time-sync.target          loaded    inactive dead   System Time Synchronized
  timers.target             loaded    active   active Timers
  umount.target             loaded    inactive dead   Unmount All Filesystems

LOAD   = Reflects whether the unit definition was properly loaded.
ACTIVE = The high-level unit activation state, i.e. generalization of SUB.
SUB    = The low-level unit activation state, values depend on unit type.

37 loaded units listed.
To show all installed unit files use 'systemctl list-unit-files'.


# systemctl status graphical.target
● graphical.target - Graphical Interface
   Loaded: loaded (/usr/lib/systemd/system/graphical.target; indirect; vendor preset: disabled)
   Active: active since Mon 2020-12-14 00:20:24 EST; 7min ago
     Docs: man:systemd.special(7)

12월 14 00:20:24 localhost.localdomain systemd[1]: Reached target Graphical Interface.

# systemctl disable  graphical.target
Removed /etc/systemd/system/default.target.

# systemctl disable graphical.target --force

# systemctl status graphical.target
● graphical.target - Graphical Interface
   Loaded: loaded (/usr/lib/systemd/system/graphical.target; static; vendor preset: disabled)
   Active: inactive (dead) since Mon 2020-12-14 00:33:58 EST; 8s ago
     Docs: man:systemd.special(7)

12월 14 00:29:09 localhost.localdomain systemd[1]: Reached target Graphical Interface.
12월 14 00:33:58 localhost.localdomain systemd[1]: Stopped target Graphical Interface.

]# systemctl list-units -t target -a
  UNIT                      LOAD      ACTIVE   SUB    DESCRIPTION
  basic.target              loaded    active   active Basic System
  cryptsetup.target         loaded    active   active Local Encrypted Volumes
  emergency.target          loaded    inactive dead   Emergency Mode
  getty-pre.target          loaded    inactive dead   Login Prompts (Pre)
  getty.target              loaded    active   active Login Prompts
  graphical.target          loaded    inactive dead   Graphical Interface
  initrd-fs.target          loaded    inactive dead   Initrd File Systems
  initrd-root-device.target loaded    inactive dead   Initrd Root Device
  initrd-root-fs.target     loaded    inactive dead   Initrd Root File System
  initrd-switch-root.target loaded    inactive dead   Switch Root
  initrd.target             loaded    inactive dead   Initrd Default Target
  local-fs-pre.target       loaded    active   active Local File Systems (Pre)
  local-fs.target           loaded    active   active Local File Systems
  multi-user.target         loaded    active   active Multi-User System
  network-online.target     loaded    active   active Network is Online
  network-pre.target        loaded    active   active Network (Pre)
  network.target            loaded    active   active Network
  nfs-client.target         loaded    active   active NFS client services
  nss-lookup.target         loaded    inactive dead   Host and Network Name Lookups
  nss-user-lookup.target    loaded    active   active User and Group Name Lookups
  paths.target              loaded    active   active Paths
  remote-fs-pre.target      loaded    active   active Remote File Systems (Pre)
  remote-fs.target          loaded    active   active Remote File Systems
  rescue.target             loaded    inactive dead   Rescue Mode
  rpc_pipefs.target         loaded    active   active rpc_pipefs.target
  rpcbind.target            loaded    active   active RPC Port Mapper
  shutdown.target           loaded    inactive dead   Shutdown
  slices.target             loaded    active   active Slices
  sockets.target            loaded    active   active Sockets
  sound.target              loaded    active   active Sound Card
  sshd-keygen.target        loaded    active   active sshd-keygen.target
  swap.target               loaded    active   active Swap
  sysinit.target            loaded    active   active System Initialization
● syslog.target             not-found inactive dead   syslog.target
  time-sync.target          loaded    inactive dead   System Time Synchronized
  timers.target             loaded    active   active Timers
  umount.target             loaded    inactive dead   Unmount All Filesystems

LOAD   = Reflects whether the unit definition was properly loaded.
ACTIVE = The high-level unit activation state, i.e. generalization of SUB.
SUB    = The low-level unit activation state, values depend on unit type.

37 loaded units listed.
To show all installed unit files use 'systemctl list-unit-files'.

[링크 : https://linuxconfig.org/how-to-change-a-runlevel-on-rhel-7-linux-system]