diff --git a/build/lib.sh b/build/lib.sh
index 371a0f9..ec604e8 100755
--- a/build/lib.sh
+++ b/build/lib.sh
@@ -157,20 +157,23 @@ get_version(){
 }
 
 lib_create_tmp_dir(){
-    local tmp_dir=$(mktemp -dt -p ${TMP_DIR} tmpdir.XXXXXX)
+    local tmp_dir
+    tmp_dir=$(mktemp -dt -p "${TMP_DIR}" tmpdir.XXXXXX)
     echo "$tmp_dir"
 }
 
 lib_check_lib_arch(){
     lib=$1
+    local tmp_dir
+    local output
     if [ ! -f "$lib" ];then
         echo ""
         return
     fi
-    local tmp_dir=$(lib_create_tmp_dir)
+    tmp_dir=$(lib_create_tmp_dir)
     cp "$lib" "$tmp_dir"
     bash -c "cd ${tmp_dir}; ar x $(basename ${lib})"
-    local output=$(find "${tmp_dir}" -name "*.o" -exec file {} \;)
+    output=$(find "${tmp_dir}" -name "*.o" -exec file {} \;)
     if echo "$output" | grep -q "Intel 80386";then
         echo "Arch of ${lib} is x86" >&2
         echo "x86"
@@ -259,7 +262,7 @@ lib_build_ncurses(){
     CMD="CFLAGS=\"${GCC_OPTS}\" "
     CMD+="CXXFLAGS=\"${GXX_OPTS}\" "
     CMD+="./configure --host=$(get_host_triple) --disable-shared --enable-static"
-    if [ "$CURRENT_ARCH"!="x86" -a "$CURRENT_ARCH"!="x86_64" ];then
+    if [ "$CURRENT_ARCH" != "x86" ] && [ "$CURRENT_ARCH" != "x86_64" ];then
         CMD+=" --with-build-cc=/x86_64-linux-musl-cross/bin/x86_64-linux-musl-gcc"
     fi
     eval "$CMD"
diff --git a/build/targets/build_gdb.sh b/build/targets/build_gdb.sh
index b737856..8c1bc60 100755
--- a/build/targets/build_gdb.sh
+++ b/build/targets/build_gdb.sh
@@ -65,8 +65,8 @@ build_gdb() {
 
 main() {
     build_gdb
-    if [ ! -f "${BUILD_DIRECTORY}/binutils-gdb/gdb/gdb" -o \
-         ! -f "${BUILD_DIRECTORY}/binutils-gdb/gdb/gdbserver/gdbserver" ];then
+    if [ ! -f "${BUILD_DIRECTORY}/binutils-gdb/gdb/gdb" ] || \
+        [ ! -f "${BUILD_DIRECTORY}/binutils-gdb/gdb/gdbserver/gdbserver" ];then
         echo "[-] Building GDB ${CURRENT_ARCH} failed!"
         exit 1
     fi
diff --git a/build/targets/build_nmap.sh b/build/targets/build_nmap.sh
index 564528f..20bd7ee 100755
--- a/build/targets/build_nmap.sh
+++ b/build/targets/build_nmap.sh
@@ -36,9 +36,9 @@ build_nmap() {
 main() {
     lib_build_openssl
     build_nmap
-    if [ ! -f "${BUILD_DIRECTORY}/nmap/nmap" -o \
-         ! -f "${BUILD_DIRECTORY}/nmap/ncat/ncat" -o \
-         ! -f "${BUILD_DIRECTORY}/nmap/nping/nping" ];then
+    if [ ! -f "${BUILD_DIRECTORY}/nmap/nmap" ] || \
+        [ ! -f "${BUILD_DIRECTORY}/nmap/ncat/ncat" ] || \
+        [ ! -f "${BUILD_DIRECTORY}/nmap/nping/nping" ];then
         echo "[-] Building Nmap ${CURRENT_ARCH} failed!"
         exit 1
     fi
@@ -63,7 +63,7 @@ main() {
     fi
     cd "${BUILD_DIRECTORY}/nmap"
     make install
-    cp -r /usr/local/share/nmap/* $NMAP_DIR
+    cp -r /usr/local/share/nmap/* "$NMAP_DIR"
     echo "[+] Copied data to Nmap data dir"
 }
 
diff --git a/build/targets/build_openssh.sh b/build/targets/build_openssh.sh
index cb5c130..14a2744 100755
--- a/build/targets/build_openssh.sh
+++ b/build/targets/build_openssh.sh
@@ -33,8 +33,8 @@ main() {
     lib_build_openssl
     lib_build_zlib
     build_openssh
-    if [ ! -f "${BUILD_DIRECTORY}/openssh-portable/ssh" -o \
-         ! -f "${BUILD_DIRECTORY}/openssh-portable/sshd" ];then
+    if [ ! -f "${BUILD_DIRECTORY}/openssh-portable/ssh" ] || \
+        [ ! -f "${BUILD_DIRECTORY}/openssh-portable/sshd" ];then
         echo "[-] Building OpenSSH ${CURRENT_ARCH} failed!"
         exit 1
     fi
@@ -43,7 +43,7 @@ main() {
     cp "${BUILD_DIRECTORY}/openssh-portable/sshd" "${OUTPUT_DIRECTORY}/sshd${OPENSSH_VERSION}"
     echo "[+] Finished building OpenSSH ${CURRENT_ARCH}"
 
-    OPENSSH_VERSION=$(echo $OPENSSH_VERSION | sed 's/-//')
+    OPENSSH_VERSION=$(echo "$OPENSSH_VERSION" | sed 's/-//')
     echo ::set-output name=PACKAGED_NAME::"${OPENSSH_VERSION}"
     echo ::set-output name=PACKAGED_NAME_PATH::"/output/*"
 }