I have an alias to do quick searchs on my terminal history by just typing h + search pattern.
alias h='history | /usr/bin/grep '
It works like it should, but I can't add more search patterns without adding more greps
instances.
e. g. h pacman | grep wine
I want to adapt it to convert other possible arguments to search pattern.
e. g. h pacman wine
Obs.: I know there are out of the box solutions to achieve that, but since I have no idea how to do it, I want to learn.
For this you'll need a shell-function instead of a shell-alias:
function h() {
code="cat ~/.bash_history"
for arg in $@ ; do
code="$code | grep $arg"
done
eval "$code"
}
You can put this function in your .bashrc or wherever you normally write your alias instruction.
The key thing here is that for multiple patterns to grep, you usually have to use the -e option to specify each pattern (so grep -e pacman -e wine instead of just grep pacman wine). Two options:
Aliases don't support arguments, so use a function:
h () {
local args=() # local array to store argument with -e for grep
for i
do
args+=(-e "$i") # tack on the -e for each argument
done
history | grep "${args[@]}"
}
This assumes all arguments will be patterns to grep.
Continue using the alias, and add the -e yourself:
h -e pacman -e wine
This way, you can also add whatever other grep options you want (say, e.g., -C 3 to show some context around the results).
