I have found a good reference: How to target multiple selections with xclip
In my case, I would like to paste content on the clipboard and also to see what is been pasted there, so I used also the tee command with a file descriptor:
echo "just a test" | tee >(xclip -i -selection clipboard)
>() is a form of process substitution. Bash replaces each with the path to a file descriptor which is connected to the standard input of the program within the parentheses.
The teecommand forks your command allowing you to "pipe its content" and see the result on standard output "stdout".
You can also create aliases to get and write on the clipboard, allowing you to use "pbcopy" and "pbpaste" as if you where on Mac. In my case, as I use Z shell (zsh), I have this in my aliases file:
(( $+commands[xclip] )) && {
alias pbpaste='xclip -i -selection clipboard -o'
alias pbcopy='xclip -selection clipboard'
}
The (( $+command[name] )) in Z shell tests if the command "name" is installed on your system, and then both aliases are grouped with {}. The && is a binary AND; if a then b, hence if you have xclip then the aliases will be set.
echo "another test" | tee >(pbcopy)
To get your clipboard content, just type:
pbpaste | "any-command-you-need-here"