Fix test command procinfo (#1706)

* Updated canary.py for better display

* Updated test_command_procinfo.py

* Revert "Updated canary.py for better display"

This reverts commit 802e243183.

* Fix lint issue

* Update test_command_procinfo.py

---------

Co-authored-by: Unknown6334 <63234449+Unknown1934-del@users.noreply.github.com>
Co-authored-by: Disconnect3d <dominik.b.czarnota@gmail.com>

tests/gdb-tests/tests/test_command_procinfo.py

@@ -1,5 +1,7 @@
 import os
 import shutil
+import signal
+import subprocess
 
 import gdb
 
@@ -11,9 +13,18 @@ REFERENCE_BINARY_NET = tests.binaries.get("reference-binary-net.out")
 def test_command_procinfo(start_binary):
     start_binary(REFERENCE_BINARY_NET)
 
-    # Sanity check, netcat must exist at this point
-    assert shutil.which("nc") is not None
-    os.system("nc -l -p 31337 2>/dev/null 1>&2 &")
+    # Check if netcat exists
+    nc_path = shutil.which("nc")
+    assert nc_path is not None, "netcat is not installed"
+
+    # Spawn netcat
+    netcat_process = subprocess.Popen(
+        [nc_path, "-l", "-p", "31337"],
+        stdin=subprocess.DEVNULL,
+        stdout=subprocess.DEVNULL,
+        stderr=subprocess.DEVNULL,
+        start_new_session=True,
+    )
 
     bin_path = gdb.execute("pi pwndbg.gdblib.proc.exe", to_string=True).strip("\n")
     pid = gdb.execute("pi pwndbg.gdblib.proc.pid", to_string=True).strip("\n")
@@ -28,6 +39,9 @@ def test_command_procinfo(start_binary):
     assert pid in res_list[1]
     assert "127.0.0.1:31337" in result
 
+    # Close netcat
+    os.killpg(os.getpgid(netcat_process.pid), signal.SIGTERM)
+
 
 def test_command_procinfo_before_binary_start():
     result = gdb.execute("procinfo", to_string=True)