InitSystem (GNU): support shepherd detection

Author: CarterLi

src/common/processing_linux.c

@@ -241,8 +241,35 @@ void ffProcessGetInfoLinux(pid_t pid, FFstrbuf* processName, FFstrbuf* exe, cons
 
     if(ffReadFileBuffer(filePath, exe))
     {
-        ffStrbufRecalculateLength(exe); //Trim the arguments
-        ffStrbufTrimRightSpace(exe);
+        const char* p = exe->chars;
+        uint32_t len = (uint32_t) strlen(p);
+
+        if (len + 1 < exe->length)
+        {
+            const char* name = memrchr(p, '/', len);
+            if (name) name++; else name = p;
+
+            // For interpreters, try to find the real script path in the arguments
+            if (ffStrStartsWith(name, "python")
+                #ifndef __ANDROID__
+                || ffStrEquals(name, "guile") // for shepherd
+                #endif
+            )
+            {
+                // `cmdline` always ends with a trailing '\0', and ffReadFileBuffer appends another \0
+                // So `exe->chars` is always double '\0' terminated
+                for (p = p + len + 1; *p && *p == '-'; p += strlen(p) + 1) // Skip arguments
+                    assert(p - exe->chars < exe->allocated);
+                if (*p)
+                {
+                    len = (uint32_t) strlen(p);
+                    memmove(exe->chars, p, len + 1);
+                }
+            }
+        }
+
+        assert(len < exe->allocated);
+        exe->length = len;
         ffStrbufTrimLeft(exe, '-'); //Login shells start with a dash
     }
 
@@ -463,6 +490,8 @@ const char* ffProcessGetBasicInfoLinux(pid_t pid, FFstrbuf* name, pid_t* ppid, i
                 return "memrchr(stat, ')') failed";
             ffStrbufSetNS(name, (uint32_t) (end - start), start);
             ffStrbufTrimRightSpace(name);
+            if (name->chars[0] == '\0')
+                return "process name is empty";
             pState = end + 2; // skip ") "
         }
 
@@ -471,10 +500,7 @@ const char* ffProcessGetBasicInfoLinux(pid_t pid, FFstrbuf* name, pid_t* ppid, i
         #endif
         {
             int ppid_, tty_;
-            if(
-                sscanf(pState + 2, "%d %*d %*d %d", &ppid_, &tty_) < 2 ||
-                name->chars[0] == '\0'
-            )
+            if(sscanf(pState + 2, "%d %*d %*d %d", &ppid_, &tty_) < 2)
                 return "sscanf(stat) failed";
 
             if (ppid)

src/detection/initsystem/initsystem_linux.c

@@ -84,16 +84,19 @@ const char* ffDetectInitSystem(FFInitSystemResult* result)
                 ffStrbufSubstrAfterLastC(&result->version, ' ');
             }
         }
-        else if (ffStrbufEqualS(&result->name, "guile"))
+        else if (ffStrbufEqualS(&result->name, "shepherd"))
         {
-            // TODO: guile is actually shepherd
-            if (ffProcessAppendStdOut(&result->version, (char* const[]) {
-                ffStrbufEndsWithS(&result->exe, "/guile") ? result->exe.chars : "guile",
-                "--version",
+           if (ffProcessAppendStdOut(&result->version, (char* const[]) {
+              ffStrbufEndsWithS(&result->exe, "/shepherd") ? result->exe.chars : "shepherd",
+              "--version",
                 NULL,
             }) == NULL && result->version.length)
             {
-                // guile (GNU Guile) 3.0.9
+                // shepherd (GNU Shepherd) 1.0.6
+                // The first line in the output might not contain the version
+                if (!ffStrbufStartsWithS(&result->version, "shepherd"))
+                    ffStrbufSubstrAfterFirstC(&result->version, '\n');
+
                 ffStrbufSubstrBeforeFirstC(&result->version, '\n');
                 ffStrbufSubstrAfterLastC(&result->version, ' ');
             }