This article was written by Hiyoung

• Linux won’t automatically create non-existent folders. When using the mv command, make sure the destination directory exists, or it will simply rename the file.
• Creating a hard link is essentially giving a file an additional name (the data itself remains unchanged). It’s similar to creating a pointer to that file in C.
• Symbolic links are like shortcuts in Windows. You can clearly see the difference using the ls -li command. Hard links have the same byte count as the source file, while symbolic links do not.

• Creating commands with alias: Use ; to run multiple commands on the same line. Use type to check if a command already exists in the system. Note that aliases created this way disappear when the shell session ends (since they aren’t saved to a file). Use unalias to remove an alias.
• Using > redirects and overwrites the target file, while >> appends to it.
• To write error messages to a file instead of displaying them on the screen, use 2>.
• There are two ways to redirect both standard output (stdout) and standard error (stderr) to the same file: first, add 2>&1 after the filename; second, use &> as the redirection operator.

Method 1 (Works in older shell versions)

Method 2