fg (1) - Linux Manuals
fg: bash built-in commands, see bash(1)
Command to display fg
manual in Linux: $ man 1 fg
NAME
bash, :, ., [, alias, bg, bind, break, builtin, caller,
cd, command, compgen, complete,
compopt, continue, declare, dirs, disown, echo, enable, eval, exec, exit,
export, false, fc, fg, getopts, hash, help, history, jobs, kill,
let, local, logout, mapfile, popd, printf, pushd, pwd, read,
readonly, return, set,
shift, shopt, source, suspend, test, times, trap, true, type, typeset,
ulimit, umask, unalias, unset, wait - bash built-in commands, see
bash(1)
BASH BUILTIN COMMANDS