TerminalShell: ignore the parent process if $FFTS_IGNORE_PARENT is set to 1

Fix #1205

Author: CarterLi

src/detection/terminalshell/terminalshell_linux.c

@@ -384,6 +384,14 @@ const FFShellResult* ffDetectShell()
     result.tty = -1;
 
     pid_t ppid = getppid();
+
+    const char* ignoreParent = getenv("FFTS_IGNORE_PARENT");
+    if (ignoreParent && ffStrEquals(ignoreParent, "1"))
+    {
+        FF_STRBUF_AUTO_DESTROY _ = ffStrbufCreate();
+        ffProcessGetBasicInfoLinux(ppid, &_, &ppid, NULL);
+    }
+
     ppid = getShellInfo(&result, ppid);
     getUserShellFromEnv(&result);
     setShellInfoDetails(&result);

src/detection/terminalshell/terminalshell_windows.c

@@ -345,6 +345,10 @@ const FFShellResult* ffDetectShell(void)
     if(!ffProcessGetInfoWindows(0, &ppid, NULL, NULL, NULL, NULL, NULL))
         return &result;
 
+    const char* ignoreParent = getenv("FFTS_IGNORE_PARENT");
+    if (ignoreParent && ffStrEquals(ignoreParent, "1"))
+        ffProcessGetInfoWindows(ppid, &ppid, NULL, NULL, NULL, NULL, NULL);
+
     ppid = getShellInfo(&result, ppid);
 
     if (result.processName.length > 0)