This bash script synchronizes local repositories with external repositories, RPM, reposync, createrepo

reposync.sh

#!/bin/bash
# requires bash version 4
# This script synchronizes local repositories with
# external repositories
#
############################################################
#                   PREREQUISITES
############################################################

for util in reposync createrepo; do
    if [ -z $(which $util) ]; then
        echo "$util is not found"
        echo -n "please verify that packages"
        echo " yum-utils and createrepo are installed"
        exit 1
    fi
done

configfile=$(dirname $(readlink -f $0))/'reposync.ini'
if [ ! -f $configfile ]; then
    echo "config file ${configfile} is not found"
    exit 1
fi

############################################################
#                   READ CONFIG FILE
############################################################

while IFS='= ' read k v; do
    if [[ $k == \[*\] ]]; then
        section=$(echo "$k" | tr -d "[] ")
        declare -A $section
    elif [[ $v ]]; then
        if [ ! $(echo $v | grep "^#") ]; then
            eval $section[$k]=$(echo "$v" | tr -d " ")
        fi
    fi
done < $configfile

# path to the root of all the repositories
reposroot=${settings[reposroot]}

# proxy settings
export http_proxy=${settings[proxy]}
export https_proxy=${settings[proxy]}

############################################################
#                   FUNCTIONS
############################################################

usage(){
    echo "
Usage: $0 [OPTION]

-h --help                    show this help
-n --name [repo1] [repo2]    synchronize only the repository(s) with the given name(s)
-l --list                    show the names of all the repositories
-a --all --syncall           synchronize all the repositories
"
}

hashHasKey() {
    # returns 1 if the key exists, otherwise 0
    eval 'local keys=${!'$1'[@]}';
    eval "case '$2' in
          ${keys// /|}) return 0 ;;
          * ) return 1 ;;
          esac";
}

hashGetValue() {
    # return value of the key, otherwise 0
    eval 'local keys=${!'$1'[@]}';
    eval "case '$2' in
          ${keys// /|}) echo \${$1[$2]};return 0 ;;
          * ) return 1 ;;
          esac";
}

############################################################
#                   USER INTERACTION
############################################################

case $# in
    0)
        usage
        exit 0
        ;;
    1)
        case $1 in
            -l|--list)
                echo -e "\nAvailable repositories:\n"
                (IFS=$'\n'; echo -e "${!reposlist[*]}\n")
                exit 0
                ;;
            -a|--all|--syncall)
                ;;
            -h|--help)
                usage
                exit 0
                ;;
            *)
                echo "$1 is an incorrect or incomplete option"
                usage
                exit 1
                ;;
        esac
        ;;
    2)
        case $1 in
            -n|--name)
                if hashHasKey reposlist $2; then
                    value=$(hashGetValue reposlist $2)
                    declare -A reposlist=( [$2]=$value )
                else
                    echo "$2 is an incorrect name of the repository, exiting"
                    exit 0
                fi
                ;;
            *)
                echo "$@ are incorrect options"
                usage
                exit 1
                ;;
        esac
            ;;
    *)
        case $1 in
            -n|--name)
                wrongname=false
                declare -A temp
                for name in ${@:2}; do
                    if ! hashHasKey reposlist $name; then
                        echo "$name is an incorrect name of the repository"
                        wrongname=true
                    else
                        value=$(hashGetValue reposlist $name)
                        temp[$name]=$value
                    fi
                done
                if $wrongname; then
                    echo "exiting"
                    exit 1
                else
                    reposlist=()
                    for idx in "${!temp[@]}"; do
                        reposlist[$idx]=${temp[$idx]}
                    done
                fi
                ;;
            *)
                echo "$@ are incorrect options"
                usage
                exit 1
                ;;
        esac
        ;;
esac

############################################################
#                   SYNCHRONIZE
############################################################

for repo in ${!reposlist[@]}; do
    if [ ${reposlist[$repo]} != "true" ] &&
       [ ${reposlist[$repo]} != "false" ]; then
        ${reposlist[$repo]}
        continue
    fi
    if ${reposlist[$repo]}; then
        reposync -dlnr $repo -p $reposroot
    fi
    if [ -f $reposroot/$repo/comps.xml ]; then
        createrepo -s sha --update $reposroot/$repo -g $reposroot/$repo/comps.xml
    else
        createrepo -s sha --update $reposroot/$repo
    fi
done