shell检测某个文件/文件夹是否存在详细实例

FILE=/etc/resolv.conf
if test -f "$FILE"; then
    echo "$FILE exist"
fi
FILE=/etc/resolv.conf
if [ -f "$FILE" ]; then
    echo "$FILE exist"
fi
FILE=/etc/resolv.conf
if [[ -f "$FILE" ]]; then
    echo "$FILE exist"
fi

FILE=/etc/docker
if [ -d "$FILE" ]; then
    echo "$FILE is a directory"
fi
[ -d /etc/docker ] && echo "$FILE is a directory"

FILE=/etc/docker
if [ ! -f "$FILE" ]; then
    echo "$FILE does not exist"
fi
[ ! -f /etc/docker ] && echo "$FILE does not exist"

if [ -f /etc/resolv.conf -a -f /etc/hosts ]; then
    echo "Both files exist."
fi
if [[ -f /etc/resolv.conf && -f /etc/hosts ]]; then
    echo "Both files exist."
fi

base="501"
exp="506"
iter_num=2
query_name="model_iter_v2"
data_dir=./data_${query_name}
result_dir=./result_${query_name}
if [ ! -d "${result_dir}" ]; then
    mkdir ${result_dir}
fi
if [  -d "${result_dir}" ]; then
    rm -rf ${result_dir}/*
fi
for var in  ${data_dir}/*; do
    query_file=${var##*/}
    cp ${data_dir}/${query_file} ${result_dir}/${query_file}_1
    head=1
    while [[ ${head} -lt ${iter_num} ]]
    do
        behind=$((${head} + 1))
        echo ${query_file}_${head}
        echo ${query_file}_${behind}
        python get_diff.py -input_file ${result_dir}/${query_file}_${head}  -b ${base} -e ${exp}  -output_file ${result_dir}/${query_file}_${behind} > ${query_file}.log
        sort -t"    " -k2,2nr ${result_dir}/${query_file}_${behind}_result > ${result_dir}/${query_file}_${behind}
        rm ${result_dir}/${query_file}_${behind}_result
        if [ ${behind} -eq ${iter_num} ]; then
            cp ${result_dir}/${query_file}_${behind} ./${query_file}_diff
        fi
        let head++
    done
done