A collection of useful bash functions.

bash_functions.sh

# Variables used
RED=$(tput setaf 1);
GREEN=$(tput setaf 2);
YELLOW=$(tput setaf 3);
WHITE=$(tput setaf 7);

# Throw an error
error() {
    printf "${RED}Error:${WHITE} ${1}\n"
    exit
}

# Throw a warning
warn() {
    printf "${YELLOW}${1}${WHITE}\n"
    exit
}

# Throw a success message
success() {
    printf "${GREEN}${1}${WHITE}\n"
}

# Remove the trailing slash from a string, if it exists
strip_trailing_slash() {
    result="$1"

    if [[ "$1" == */ ]]; then
        result=$(echo "$1" | rev | cut -c 2- | rev)
    fi

    echo "$result"
}

# Escape characters in a string
escape() {
  printf "%q " $1
}

# URL encode a string
rawurlencode() {
    local string="${1}"
    local strlen=${#string}
    local encoded=""

    for (( pos=0 ; pos<strlen ; pos++ )); do
        c=${string:$pos:1}
        case "$c" in
            [-_.~a-zA-Z0-9] ) o="${c}" ;;
            * )               printf -v o '%%%02x' "'$c"
        esac
        encoded+="${o}"
    done
    
    echo "${encoded}"
}

# Print a message like a typewriter
typewrite() {
    MESSAGE_TYPE="$1"
    MESSAGE="$2"

    case $MESSAGE_TYPE in
        'success' )
            printf "${GREEN}"
            ;;
        'warn' )
            printf "${YELLOW}"
            ;;
        'error' )
            printf "${RED}"
            ;;
        'normal' )
            ;;
        * )
            error "Error: Message type \"$MESSAGE_TYPE\" doesn't exist."
            exit
            ;;
    esac

    SPOT=0
    while true; do
        printf "${MESSAGE:SPOT:1}"
        SPOT=$(($SPOT+1))

        # Generate a random decimal
        DELAY_INT=$(( ( RANDOM % 10 ) + 1 ))
        sleep "0.0$DELAY_INT"

        if [ ${#MESSAGE} -eq "$SPOT" ]; then
            printf "${WHITE}"
            printf "\n"
            break
        fi
    done
}