added build archive exists check

reinstall-magisk-on-lineageos

@@ -42,6 +42,15 @@ get_build_url() {
         head -1
 }
 
+check_exists_latest_lineageos_build() {
+    # The --location lets curl follow the redirection.
+    curl --location "$(get_build_url)?sha256" --output /tmp/lineageos.sha256
+    hash1=$( awk '{print $1}' lineageos.sha256 )
+    hash2=$( sha256sum lineageos.zip | awk '{print $1}' )
+    [[ "$hash1" =~ "$hash2" ]]
+    return
+}
+
 download_latest_lineageos_build() {
     # The --location lets curl follow the redirection.
     curl --location "$(get_build_url)" --output /tmp/lineageos.zip
@@ -163,8 +172,12 @@ main() {
     is_rooted_debugging_enabled
     print_message "Checking on phone if Magisk is installed"
     check_magisk_app
+    if check_exists_latest_lineageos_build; then
+        print_message "Build archive already exists, skipping download"
+    else
         print_message "Downloading build archive from $(get_build_url)"
         download_latest_lineageos_build
+    fi
     print_message "Extracting 'boot.img' from build archive in /tmp/boot.img"
     extract_boot_image
     print_message "Copying from PC to phone the boot image in /sdcard/Download/boot.img"