which is the correct way to copy text content inside a .pub file without opening the file, so that I can add it to git to grant access with the key?

Question

i'm using ubuntu but the PBCOPY dont work, cant seem to figure out the alias ~gedit to work right.. or how do i open the .pub file and copy key from there?

i tried the cbcopy command, ubuntu doesnt recognise it, ive gotten into the gedit and added alias="like this" and saved and closed and tried it but that didnt work, possibly i did it wrong?

i dont care that the alias doesnt save my copy command, i only need it to copy the key that was saved in my .pub file so i can share it with github so i can continue my learning on coursera and forage and submit my work! so irritating! thanx