useful functions for bash scripts

bash-utils.sh

#!/bin/bash

# print green
function info {
    echo -e "\e[0;32m"$@"\e[0m"
}

# print yellow
function warn {
    echo -e "\e[0;33m"$@"\e[0m"
}

# print red
function error {
    echo -e "\e[0;31m"$@"\e[0m"
}

# command line parser
function parse_cmd_line {
    # first argument of parse_cmd_line function must be a string space-separated
    # containing the valid positional arguments
    # second argument must be a string space-separated containing the valid
    # optional arguments
    # third argument must be "$@"
    #
    # Example:
    # parse_cmd_line "<arg1> <arg2> [opt1]" "--flag1 --flag2=10" bla ble bli --flag1
    #
    # after executing this call the following variables are created?
    # arg1=bla
    # arg2=ble
    # opt1=bli
    # flag1=1
    # flag2=10

    # get arguments and convert them to array
    local pos_args=($1)
    shift
    local opt_args=($1)
    shift

    # make variables local
    local arg=""
    local opt=""
    local var=""
    local val=""

    # create variables of optional arguments with default values
    for opt in ${opt_args[@]}; do
        if [[ "$opt" == *"="* ]]; then
            # extract variable name and its value
            var=`echo ${opt:2} | cut -d'=' -f1 | sed 's/-/_/g'`
            val=`echo ${opt:2} | cut -d'=' -f2`

            # create variable
            eval `echo $var=$val`
        fi
    done

    # loop all arguments
    local recv_count=0
    for arg in $@; do
        # check if it's an "OPTIONS" argument
        if [[ "${arg::2}" == "--" ]]; then
            # check if received option is valid
            for opt in ${opt_args[@]}; do
                # get variable name replacing dash by underscore
                var=`echo ${arg:2} | cut -d'=' -f1 | sed 's/-/_/g'`

                if [[ `echo $opt | cut -d'=' -f1` == \
                      `echo $arg | cut -d'=' -f1` ]]; then

                    # check if a value has been provided
                    if [[ "$arg" == *"="* ]]; then
                        val=`echo ${arg:2} | cut -d'=' -f2`

                    # force variable to have a value
                    else
                        val="1"
                    fi

                    # create variable
                    eval `echo $var=$val`
                    break
                fi
            done
        else
            # create variables of the positional arguments
            var=`echo ${pos_args[$recv_count]} | sed 's/[]<>[]//g'`
            eval `echo $var=$arg`
            recv_count=$((recv_count+1))
        fi
    done

    # count required arguments
    local req_count=0
    for arg in ${pos_args[@]}; do
        if [[ "${arg::1}" == "<" && "${arg: -1}" == ">" ]]; then
            req_count=$((req_count+1))
        fi
    done

    # check if all required arguments were received
    if [[ "$recv_count" < "$req_count" ]]; then
        ret=1
    else
        ret=0
    fi
}