install-helpful-shell-scripts

#!/usr/bin/zsh

# NOTE TO SELF: I would like the arrow printouts to be lined up; maybe write a function to calculate the necessary white space needed to do that?
# NOTE TO SELF: While I'm at it, why not add a flag for dry runs; it would only be useful for testing the script but hey, why not?

THIS_NAME="${0##*/}"
WARN_MSG_PERMISSIONS="[$THIS_NAME][WARNING] You need special permissions to write to this directory! Trying sudo...\n"
ERR_MSG_SPECIFY_LOCATION="Please specify the install location.\n"
ERR_MSG_INVALID_LOCATION="Install location does not exist!\n"
ERR_MSG_INSTALL_SCRIPT_MOVED="The install script has been moved! Please put it back in the Github repository directory.\n"
INSTALL_FILE_REALPATH="$(realpath $0)"
SCRIPTS_LOCATION="${INSTALL_FILE_REALPATH%/*}"
INSTALL_LOCATION="$1"
TEST_FILE="$INSTALL_LOCATION/.test"
LONGEST_NAME=""

FILE_COLOR="\x1b[1;36m"
ARROWS_COLOR="\x1b[1;39m"
LINK_COLOR="\x1b[1;32m"
RESET="\x1b[0m"

throw_error()
{
    printf "[$THIS_NAME][ERROR] $1" >&2
    exit 1
}

equal_lengths()
{
    for file in $SCRIPTS_LOCATION/*; do
        if [[ ! "$file" =~ "install-helpful-shell-scripts" && ! "$file" =~ "README.md" ]]; then
            if [[ ${#file} -gt ${#LONGEST_NAME} ]]; then
                LONGEST_NAME="$file"
            fi
        fi
    done
}

install()
{
    if [[ ! "$INSTALL_FILE_REALPATH" =~ "HelpfulShellScripts" ]]; then
        throw_error "$ERR_MSG_INSTALL_SCRIPT_MOVED"
    fi
    equal_lengths
    for file in "$SCRIPTS_LOCATION"/*; do
        if [[ ! "$file" =~ "install-helpful-shell-scripts" && ! "$file" =~ "README.md" ]]; then
            LINKED_FILE="${INSTALL_LOCATION%/}/${file##*/}"
            NUMBER_OF_SPACES=$((${#LONGEST_NAME} - ${#file}))
            SPACES=""
            for ((i = 0 ; i < $NUMBER_OF_SPACES ; i++)); do
                SPACES="$SPACES "
            done
            printf "Creating static link: $FILE_COLOR$file$SPACES$ARROWS_COLOR -> $LINK_COLOR$LINKED_FILE$RESET\n"
            rm -f "$LINKED_FILE" &>/dev/null
            ln -s "$file" "$LINKED_FILE"
        fi
    done
}

if [[ -z "$INSTALL_LOCATION" ]]; then
    throw_error "$ERR_MSG_SPECIFY_LOCATION"
fi

if [[ ! -e "$INSTALL_LOCATION" ]]; then
    throw_error "$ERR_MSG_INVALID_LOCATION"
fi

if [[ $(touch "$TEST_FILE" &>/dev/null ; echo "$?") -eq 1 ]]; then
    printf "$WARN_MSG_PERMISSIONS"
    sudo install
    exit 0
else
    rm "$TEST_FILE"
fi

install