为什么“：l”在zsh脚本中消失了

Question

I wrote a function in my .zshrc:

cnj(){
    port=0;
    echo -n "Enter number of port > ";
    read port;

    a="ssh -N -f -L localhost:$port:localhost:$port  name@ip";
    echo $a;
}

the result shows that :

ssh -N -f -L localhost:8909ocalhost:8909 name@ip

why

:l

disappear in

localhost:8909ocalhost:8909

Answer 1

This is an instance of the colon modifier syntax .

$var:l in particular converts the contents of $var to lowercase.

To prevent :l being interpreted as modifier you can add braces around the variable name:

"...${port}:localhost:..."