about cp command

By `alias` command, you will see the following info in some os(For example, `rhel7.4`).
By default, `cp` is `cp -i`.
Under this situation, you need use `\cp` to the origin command.(e.g. ,`\cp -f`)
```bash
alias cp='cp -i'
alias egrep='egrep --color=auto'
alias fgrep='fgrep --color=auto'
alias grep='grep --color=auto'
alias l.='ls -d .* --color=auto'
alias ll='ls -l --color=auto'
alias ls='ls --color=auto'
alias mv='mv -i'
alias rm='rm -i'
alias which='alias | /usr/bin/which --tty-only --read-alias --show-dot --show-tilde'
```