Question

I’m trying to parse the android source directory and i need to extract all the directory names excluding certain patterns. If you notice below., for now i included only 1 directory to the exclude list, but i will be adding more.,

The find command doesn’t exclude the directory with name ‘docs’.

The commented out line works., but the other one doesn’t. For easy debugging, i included the min and maxdepth which i would remove later.

Any comments or hints on why it doesn’t work?

#! /bin/bash
ANDROID_PATH=$1
root=/
EXCLUDES=( doc )
cd ${root}
for dir in "${EXCLUDES[@]}"; do
    exclude_name_cmd_string=${exclude_name_cmd_string}$(echo \
                            "-not -name \"${dir}*\" -prune")
done
echo -e ${exclude_name_cmd_string}
custom_find_cmd=$(find ${ANDROID_PATH} -mindepth 1 -maxdepth 1 \
                    ${exclude_name_cmd_string} -type d)
#custom_find_cmd=$(find ${ANDROID_PATH} -mindepth 1 -maxdepth 1 \
#                    -not -name "doc*" -prune -type d)
echo ${custom_find_cmd} 

Answer 1

Building up a command string with possibly-quoted arguments is a bad idea. You get into nested quoting levels and eval and a bunch of other dangerous/confusing syntactic stuff.

Use an array to build the find; you’ve already got the EXCLUDES in one.

Also, the repeated -not and -prune seems weird to me. I would write your command as something like this:

excludes=()

for dir in "${EXCLUDES[@]}"; do
  excludes+=(-name "${dir}*" -prune -o) 
done

find "${ANDROID_PATH}" -mindepth 1 -maxdepth 1 "${excludes[@]}" -type d -print

The upshot is, you want the argument to -name to be passed to find as a literal wildcard that find will expand, not a list of files returned by the shell’s expansion, nor a string containing literal quotation marks. This is very hard to do if you try to build the command as a string, but trivial if you use an array.

Friends don’t let friends build shell commands as strings.