Shell scripting: Receiving error `cat: illegal option -- A` when passing `CA` as parameter to shell function, other 2 letter params work as expected

Question

I thought this was a weird one-off glitch at first, but now I've found a second completely different bash function with the same behavior, so I'm reaching out for help because it's driving me mad.

Context: I'm working on a Mac with ZSH as my shell. I have a few helper scripts in the form of shell functions to automate a few things I do regularly. Most of them require a parameter to be passed. That parameter is a 2 letter country code (AU, CA, UK, DE, etc). Most of them work just fine, but there are two functions that fail when CA is passed as the parameter.

The error:

cat: illegal option -- A
usage: cat [-belnstuv] [file ...]

Notes while testing, applies to both functions:

• Confirmed directories exists.
• All other country codes work (US, UK, AU, DE, JP).
• Lowercase ca works.
• Other random 2 letter strings ending with A work.
• Other random 2 letter strings starting with C work.
• Using just A also works, as in taillog A.

Failing function 1, ran with: taillog CA

function taillog() {
    local grey="1;30"
    local red="1;31"
    local green="1;32"
    local yellow="1;33"
    local cyan="1;36"
    tail -f /Users/myUser/Sites/Country-"$1"/logs/error.log \
    | GREP_COLOR="$green" grep -E --color=always --line-buffered "(\[php7?:info\])|$" \
    | GREP_COLOR="$cyan" grep -E --color=always --line-buffered "(\[php7?:notice\])|$" \
    | GREP_COLOR="$yellow" grep -E --color=always --line-buffered "(\[php7?:warn\])|(?i:warn(ing))|$" \
    | GREP_COLOR="$red" grep -E --color=always --line-buffered "(\[php7?:error\])|(?i:error(s))|(?i:fatal)|$" \
    | GREP_COLOR="$grey" grep -E --color=always --line-buffered "(?i:debug)|$"
}

Failing function 2, ran with findChanged CA 600

function findChanged() {
    find /Users/myUser/Sites/Country-"$1"/public/wp-content/plugins -type f -cmin -"$2" -not -path "*/\.git/*" | more
}

All other country codes work as expected. What is it about CA that causes cat to complain? It's driving me batty.

Answer 1

Turns out that one of my ZSH plugins, "common-aliases" was injecting a global alias, alias -g CA="2>&1 | cat -A", causing any input of CA to expand to cat -A. That's what was causing my troubles. Removing that line allows the shell functions listed above to execute as expected.