Build find command from arguments in a POSIX compliant shell script

Question

I'd like to know if it's possible to write a POSIX compliant script that builds a find command from its arguments.

The way to do it for Bash (and zsh) is explained in this other SE article but it's using facilities that are bash (or zsh) specific.

The original question was to be able to build a find command like this:

find -iname '*foo*' -o -iname '*bar*' -o -iname '*blah*'

The answer is with the following Bash script code:

findany() {
    local args=('-iname' "*$1*")
    shift

    while [ "$#" -gt 0 ]; do
        args+=('-o' '-iname' "*$1*")
        shift
    done

    find . "${args[@]}"
}

Is it possible to do something similar in a POSIX-compliant script?

Answer 1

There is only one array in POSIX shells - the array of arguments. You could use that here:

findany() {
    n=$#    # Save the original number of arguments
    if [ "$n" -gt 0 ]
    then
        for arg # Loop over function arguments
        do
            # Overwrite the arguments with existing args + additional options
            # with the currently processed argument
            set -- "$@" -o -iname "*$arg*"
        done
        # Remove the original set of arguments and the `-o` after them,
        # leaving only the `-iname ...` ones.
        shift $((n+1))
    fi
    # Pass `-iname ...` arguments, if any, to find
    find . "$@"
}

This should work just fine in bash or zsh as well.

Answer 2

Similar to @muru's answer but more canonical with for arg do; set -- ...; shift; done:

findany() {
  for arg do
    set -- "$@" -o -name "*$arg*"
    shift
  done
  [ "$#" -eq 0 ] || shift # remove first -o
  find . "$@"
}

Note that -iname is not POSIX, here replaced with case sensitive but standard -name (use findany '[fF][oO][oO]' for files whose name contains foo case insensitively).