Linux CMD

Command on file and directory

• cd directory -- go to the directory
• cd .. -- back to previous directory
• pwd -- show current directory
• ls -- show directory listing
• ls -al -- formated listing with hidden files
• ls /dir -- to find the file list of current location dir
• rm file -- delete file
• rm -r dir -- delete the directory
• rm -f file --force remove file
• rm -fr dir -- force remove directory
• cp file1 dir/file2 -- copy file1 and save as file2 on the location dir
• cp dir1 dir/dir2 -- copy dir1 and save as dir2 on the location dir
• mv file1 dir/file2 -- move and rename file1 as file2 on the location dir
• mv file1 dir/ -- move file1 on the location dir
• mv dir1 dir/dir2 -- move and rename dir1 as dir2 on the location dir
• mv dir1 dir/ -- move dir1 on the location dir
• ln -s dir/file /targetdir/filename -- create symbolic link or soft link to file
• ln dir/file /targetdir/filename -- create hard link to file
• ls -lrt *rpm -- search rpm on this directory
• touch file -- create or update file
• touch uzzal.txt echo "i am uzzal" > uzzal.txt -- create a file uzzal.txt and write on it "i am uzzal"
• cat dir/file or more dir/file -- to show content of a file
• cat > dir/file -- place standared content to file
• head file -- output the first 10 lines of file
• tail file or tail -f file -- output the last 10 lines of file
• vim /etc/hosts -- to edit host file

  		>i enter
  		>can change
  		>esc enter
  		>: wq! enter
  	

• rpm -qa --last -- last install package list
• yum remove package_name -- to remove package
• unzip dir/zipfile.zip -- to extract zip file
• gunzip apache-tomcat-9.0.55.tar.gz -- unzip .gz
• tar xf apache-tomcat-9.0.55.tar -- unzip .tar
• wget https://www.rarlab.com/rar/rarlinux-x32-700b2.tar.gz -- download .tar.gz file
• rpm -Uvh https://dl.fedoraproject.org/pub/epel/epel-release-latest-8.noarch.rpm -- download .rpm package
• tar -zxvf file.tar.gz -- extract .tar.gz file
• yum install -y https://rpms.remirepo.net/enterprise/remi-release-8.rpm -- yump install .rpm package

How to Disk Space

• df -h shows disk space in human-readable format
• df -a shows the file system's complete disk usage even if the Available field is 0
• df -T shows the disk usage along with each block's filesystem type (e.g., xfs, ext2, ext3, btrfs, etc.)
• df -i shows used and free inodes
• du -h /var/www/html ---VVV
• du -a shows disk usage for all files
• du -sh /var/www/html total disk space used by a particular file or directory