fix: Remove cat (#561)

.github/workflows/check.yml

@@ -11,4 +11,4 @@ jobs:
       - name: Run ShellCheck
         uses: ludeeus/action-shellcheck@master
 env:
-        SHELLCHECK_OPTS: -x --source-path=src -e SC2001 -e SC2002 -e SC2223 -e SC2034 -e SC2064 -e SC2317 -e SC2153 -e SC2028
+        SHELLCHECK_OPTS: -x --source-path=src -e SC2001 -e SC2223 -e SC2034 -e SC2064 -e SC2317 -e SC2153 -e SC2028

src/check.sh

@@ -9,7 +9,7 @@ address="/run/shm/qemu.ip"
 
 [ ! -f  "$file" ] && echo "DSM has not enabled networking yet.." && exit 1
 
-location=$(cat "$file")
+location=$(<"$file")
 
 if ! curl -m 20 -ILfSs "http://$location/" > /dev/null; then
 
@@ -19,7 +19,7 @@ if ! curl -m 20 -ILfSs "http://$location/" > /dev/null; then
     echo "Failed to reach DSM at port $port"
   else
     echo "Failed to reach DSM at http://$location"
-    ip="$(cat "$address")"
+    ip=$(<"$address")
   fi
 
   echo "You might need to whitelist IP $ip in the DSM firewall." && exit 1

src/install.sh

@@ -4,7 +4,7 @@ set -Eeuo pipefail
 : ${URL:=''}    # URL of the PAT file to be downloaded.
 
 if [ -f "$STORAGE/dsm.ver" ]; then
-  BASE=$(cat "$STORAGE/dsm.ver")
+  BASE=$(<"$STORAGE/dsm.ver")
 else
   # Fallback for old installs
   BASE="DSM_VirtualDSM_42962"

src/power.sh

@@ -36,7 +36,7 @@ finish() {
 
   if [ -f "$QEMU_PID" ]; then
 
-    pid="$(cat "$QEMU_PID")"
+    pid=$(<"$QEMU_PID")
     echo && error "Forcefully terminating QEMU process, reason: $reason..."
     { kill -15 "$pid" || true; } 2>/dev/null
 
@@ -65,7 +65,7 @@ terminal() {
   if [ -f "$QEMU_OUT" ]; then
 
     local msg
-    msg="$(cat "$QEMU_OUT")"
+    msg=$(<"$QEMU_OUT")
 
     if [ -n "$msg" ]; then
 
@@ -117,7 +117,7 @@ _graceful_shutdown() {
     finish "$code" && return "$code"
   fi
 
-  pid="$(cat "$QEMU_PID")"
+  pid=$(<"$QEMU_PID")
 
   if ! isAlive "$pid"; then
     echo && error "QEMU process does not exist?"

src/print.sh

@@ -61,7 +61,7 @@ done
 
 [ -f "$shutdown" ] && exit 1
 
-location=$(cat "$file")
+location=$(<"$file")
 
 if [[ "$location" != "20.20"* ]]; then
 
@@ -69,7 +69,7 @@ if [[ "$location" != "20.20"* ]]; then
 
 else
 
-  ip="$(cat "$address")"
+  ip=$(<"$address")
   port="${location##*:}"
 
   if [[ "$ip" == "172."* ]]; then

src/server.sh

@@ -53,7 +53,7 @@ else
   HTML=$(html "xxx")
 
   { echo "#!/bin/bash"
-    echo "[ -f \"/run/shm/dsm.url\" ] && LOCATION=\$(cat \"/run/shm/dsm.url\")"
+    echo "[ -f \"/run/shm/dsm.url\" ] && LOCATION=\$(</run/shm/dsm.url)"
     echo "HTML=\"$HTML\"; [ -z \"\$LOCATION\" ] && BODY=\"$WAIT\" || BODY=\"$BODY\"; HTML=\${HTML/xxx/\$BODY}"
     echo "printf '%b' \"HTTP/1.1 200 OK\\nContent-Length: \${#HTML}\\nConnection: close\\n\\n\$HTML\""
   } > "$TMP_FILE"