Terminal command, frequently used

Terminal Command

Unix (Lunux)

  • Basic
man # search manual
clear # clear window
pwd # print working directory
ls # list folder and files in current directory
open . # open current directory in gui
cd # change directory
cd .. # upper directory
cd ~ # home directory
cd - # previous directory
find . -type file -name "*.txt" # find *.txt files in current directory
find . -type file -name "*.json" # find *.json files in current directory
find . -type directory -name "*2" # find * directory named *2 in current directory
which # find location of installed application
touch new_file1.txt # generate file
chmod 777 new_file1.txt # change permission read, write and execution for all user
cat new_file1.txt # print 1st line
echo "hello world" > new_file3.txt # print "hello world to new_file3.txt" (overwrite)
echo "goodbye world" >> new_file3.txt # append
mkdir dir3 # make directory
mkdir -p dir4/subdir1
  • chmode 권한 777 755 가 무슨 뜻?
권한 숫자 권한 소유자(Owner) 그룹(Group) 다른 사용자(Other)
7 읽기, 쓰기, 실행 O O O
6 읽기, 쓰기 O O  
5 읽기, 실행 O O  
4 읽기 O O  
3 쓰기, 실행 O   O
2 쓰기 O    
1 실행 O    
0 권한 없음      
  • File
cp new_files1.txt dir3 # copy file
mv new_files3.txt dir4/ # move file
rm -r dir3 # remove directory
rm new_files1.txt # remove file
grep "world" *.txt # Global Regular Expression Print
grep -n "world" *.txt # print nth line including "world"
grep -ni "world" *.txt # grep insensitivite
grep -nir "world" .txt # grep insensitive and recursive
for dir in */; do mv "$dir" "Pop_$dir"; done # 폴더 이름 앞에 prefix 일괄 붙이기
  • Environment variables
export MY_DIR="dir1" # set environment variable
env # print all environment variable
cd $MY_DIR # how to use; $MY_DIR
unset $MY_DIR # unset
  • super user permission 
    sudo su
# password
  • super user permission 2 
    sudo usermod -aG docker $USER
sudo reboot

Reference

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