How many arguments can I pass to a bash function?

Question

Is the number of arguments that a bash function can accept limited?

Answer 1

To access arguments in a function, you can iterate over them:

foo () {
    for arg    # "in $@" is implied
    do
        echo $arg
    done
}

or

bar () {
    while [ $1 ]
    do
        echo $1
        shift
    done
}

or to access specific arguments:

baz () {
    # for arguments above $9 you have to use curly braces
    echo $1 $9 ${10} ${121375}
}

Answer 2

The number is fairly large:

$ display_last_arg() { echo "${@: -1}"; }
$ getconf ARG_MAX
262144
$ display_last_arg {1..262145}
262145
$ echo $(( 2**18 )) $(( 2**20 ))
262144 1048576
$ display_last_arg {1..1048576}
1048576

As you can see, it's larger than the kernel ARG_MAX limit, which makes sense since Bash does not call execve(2) to invoke Bash-defined functions.

I get malloc failures if I try to perform Bash sequence expansion ({1..NUM}) in the 2^32 range, so there is a hard limit somewhere (might vary on your machine), but Bash is so slow once you get above 2^20 arguments, that you will hit a performance limit well before you hit a hard limit.