diff --git a/install.sh b/install.sh
index 89a409e..5f08870 100644
--- a/install.sh
+++ b/install.sh
@@ -1,8 +1,8 @@
-#!/bin/bash
+#!/bin/sh
 
-HMM_PATH="$(dirname $0)/h-m-m"
-MINIMUM_REQUIREMENTS="MINIMUM REQUIREMENTS: PHP 7+ and one of these three must exist on PATH: xclip, xsel or wl-clipboard\n"
-DESTINATION_DIR="/usr/local/bin"
+HMM_PATH=$(dirname "$0")/h-m-m
+MINIMUM_REQUIREMENTS="MINIMUM REQUIREMENTS: PHP 7+ and one of these three must exist on PATH: xclip, xsel or wl-clipboard."
+DESTINATION_DIR=/usr/local/bin
 
 # Test if /usr/local/bin exists. If not fallback to /usr/bin
 if [ ! -d "$DESTINATION_DIR" ]; then
@@ -11,67 +11,57 @@ fi
 
 # If h-m-m doesn't exist in the same directory as this script, tries to download from github repository
 if [ ! -f "$HMM_PATH" ]; then
-
-    if [[ $(curl --write-out '%{http_code}' --silent https://raw.githubusercontent.com/nadrad/h-m-m/main/h-m-m --output /dev/null) == 200 ]]; then
-        curl --silent https://raw.githubusercontent.com/nadrad/h-m-m/main/h-m-m --output /tmp/h-m-m
-
-        if [ $? -ne 0 ]; then
-            echo -e "ERROR: Could not download h-m-m\n"
-            exit 1
-        fi
-
+    if [ "$(curl --write-out '%{http_code}' --silent https://raw.githubusercontent.com/nadrad/h-m-m/main/h-m-m --output /tmp/h-m-m)" = "200" ]; then
         HMM_PATH="/tmp/h-m-m"
     else
-        echo -e "ERROR: Online repository not available or Internet is down\n"
+        printf "ERROR: Could not download h-m-m\n"
         exit 1
     fi
 fi
 
-echo -e "\n> Installer for h-m-m\n"
+printf "\n> Installer for h-m-m\n\n"
 
 # Test if php is on PATH
-if ! command -v php &> /dev/null ;then
-    echo -e "ERROR: php executable not found on PATH. Installation cancelled.\n";
-    echo -e $MINIMUM_REQUIREMENTS
+if ! command -v php > /dev/null 2>&1;then
+    printf "ERROR: php executable not found on PATH. Installation cancelled.\n";
+    printf "%s\n" "$MINIMUM_REQUIREMENTS"
     exit 1
 fi
 
 # Test if xclip, xsel or wl-clipboard are on PATH
-if ! command -v xclip &> /dev/null && ! command -v xsel &> /dev/null && ! command -v wl-clipboard &> /dev/null ;then
-    echo -e "ERROR: xclip, xsel or wl-clipboard must exist on PATH. Installation cancelled.\n";
-    echo -e $MINIMUM_REQUIREMENTS
+if ! command -v xclip > /dev/null 2>&1 && ! command -v xsel > /dev/null 2>&1 && ! command -v wl-clipboard > /dev/null 2>&1 ;then
+    printf "ERROR: xclip, xsel or wl-clipboard must exist on PATH. Installation cancelled.\n";
+    printf "%s\n" "$MINIMUM_REQUIREMENTS"
     exit 1
 fi
 
 # Ask for user confirmation to install the script
-echo -e "This script will install h-m-m on $DESTINATION_DIR and make it executable.\n"
-echo -e "Proceed (y/N)?"
+printf "This script will install h-m-m on %s and make it executable.\n" "$DESTINATION_DIR"
+printf "Proceed (y/N)?"
 
-read a </dev/tty
+read -r a </dev/tty
 
-if [[ ! "$a" =~ ^(y|Y) ]] ;then
-    echo -e "Installation cancelled."
+if ! printf "%s" "$a" | grep -q "^[yY]"; then
+    printf "Installation cancelled.\n"
     exit 125
 fi
 
 # Ask for user confirmation to overwrite if the script is already installed
 if test -f "$DESTINATION_DIR/h-m-m"; then
-    echo -e "The file $DESTINATION_DIR/h-m-m already exist.\n"
-    echo -e "Overwrite (y/N)?"
+    printf "The file %s/h-m-m already exist.\n" "$DESTINATION_DIR"
+    printf "Overwrite (y/N)?"
 
-    read a </dev/tty
+    read -r a </dev/tty
 
-    if [[ ! "$a" =~ ^(y|Y) ]] ;then
-        echo -e "Installation cancelled."
+    if ! printf "%s" "$a" | grep -q "^[yY]"; then
+        printf "Installation cancelled.\n"
         exit 125
     fi
 fi
 
 # Copy the script
-sudo cp $HMM_PATH $DESTINATION_DIR/h-m-m
-
-if [ $? -ne 0 ]; then
-   echo -e "ERROR: Could not copy h-m-m to $DESTINATION_DIR\n"
+if ! sudo cp "$HMM_PATH" "$DESTINATION_DIR/h-m-m"; then
+   printf "ERROR: Could not copy h-m-m to %s\n" "$DESTINATION_DIR"
    exit 1
 fi
 
@@ -81,9 +71,9 @@ rm -f /tmp/h-m-m
 # Make the copied file executable
 sudo chmod +x $DESTINATION_DIR/h-m-m
 
-if [ $? -ne 0 ]; then
-   echo -e "ERROR: Could not make the script $DESTINATION_DIR/h-m-m executable.\n"
+if ! sudo chmod +x $DESTINATION_DIR/h-m-m; then
+   printf "ERROR: Could not make the script %s/h-m-m executable.\n" "$DESTINATION_DIR"
    exit 1
 fi
 
-echo -e "\nSUCCESS! h-m-m installed.\n"
+printf "\nSUCCESS! h-m-m installed.\n"