PF Firewall : Every time I use `pfctl`, I get errors about ALTQ support
I am probably missing something, because this does not seem to be a complex question. If you what to screen out these 2 error messages, then enter the command given below.

pfctl &gt;2 &gt;(grep -v -e "No ALTQ support in kernel" -e "ALTQ related functions disabled" 1&gt;&amp;2)


I omitted any parameters that would normally occur between pfctl and &gt;2. A function could be defined which would simplify the use of this command. One such function implementation is shown below.

pfctl() {
    command pfctl "$@" &gt;2 &gt;(grep -v -e "No ALTQ support in kernel" -e "ALTQ related functions disabled" 1&gt;&amp;2)
}


Under certain conditions, the above solution could result in the output appearing "out of order". This could be corrected by piping the output through the cat command. In other words, you could use the command given below.

pfctl &gt;2 &gt;(grep -v -e "No ALTQ support in kernel" -e "ALTQ related functions disabled" 1&gt;&amp;2) | cat


Also the function could be replaced with the one given below.

pfctl() {
    command pfctl "$@" &gt;2 &gt;(grep -v -e "No ALTQ support in kernel" -e "ALTQ related functions disabled" 1&gt;&amp;2) | cat
}


References
Bash Redirections Cheat Sheet