awk function with a number parameter for the column you want to print

Question

I want to use my awk shortcut as a function, so that I can pass the column number which then prints me the output. My aliases are:

alias A="| awk '{print \$1}'
alias G="| grep -i'

Instad of typing:

ps -ef | grep mysql | awk 'print $2'

I want to be able to type this:

ps -ef G mysql A 2

Any suggestions?

Answer 1

I don't think it's possible. Basically, aliases can't take arguments ($1), and functions can't do macro expansion (|).

The closest options I can think of:

in bash or zsh

C() { col=$1; shift; eval "awkcmd='{ print \$$col }'"; echo "$awkcmd"; "$@" | awk "$awkcmd"; }

C 2 ps -ef G mysql

in zsh

alias -g F="| tr -s '[[:space:]]' | cut -d ' ' -f"

ps -ef G mysql F 2

Answer 2

Putting pipes into aliases is awkward. Instead, create a shell function that you can pipe things to:

G () {
    grep -i "$@"
}

A () {
    awk -v col="$1" '{ print $col }'
}

Then,

ps -ef | G mysql | A 2

But this particular pipeline would, on a Linux system, be more or less the same as

pgrep mysql