feat: pmm system-install mode (default) — /usr/bin, /etc/pmm, system lib, no env vars

Default (no -p) now installs like a system package manager:
- pmm config/db -> /etc/pmm, cache -> /var/cache/pmm, pmm binary -> /usr/bin.
- .pdm data routed by type: bin -> /usr/bin, lib -> /usr/lib/<pkg-subpath>,
  etc -> /etc/pmm/<pkg>, else -> /usr/share/pmm/<pkg>; then ldconfig.
- pmm_remove removes the recorded absolute system dests.
- pmm_add_to_path is a no-op in system mode (system paths are auto-found);
  the -p <path> local mode keeps the old ~/.pmm + PATH/LD_LIBRARY_PATH behavior.
Verified: routing moves (no double multiarch), and -p local mode still writes env.

src/pdm.c

@@ -597,6 +597,34 @@ int pdm_install_file(const char *pdmfile) {
         flatten_bin(".");   /* cwd = the install address in flat mode */
     }
 
+    /* system-install mode (default, no -p): route the staged files to system
+     * destinations (ELF->/usr/bin, .so->system lib dir, etc->/etc/pmm/<pkg>,
+     * else->/usr/share/pmm/<pkg>) and record the absolute dest paths for remove. */
+    int sys_mode = (!flat && pmm_system_mode());
+    char destfile[1500];
+    if (sys_mode) {
+        snprintf(destfile, sizeof(destfile), "%s/.pmm-dests.txt", home);
+        char cmd2[9000];
+        snprintf(cmd2, sizeof(cmd2),
+            "DESTFILE=\"%s\"; cd \"%s\" && : > \"$DESTFILE\" && "
+            "MULTI=$(uname -m | sed 's/x86_64/x86_64-linux-gnu/; s/aarch64/aarch64-linux-gnu/; s/armv7l/arm-linux-gnueabihf/'); "
+            "[ -n \"$MULTI\" ] || MULTI=x86_64-linux-gnu; "
+            "find . -type f | while IFS= read -r f; do "
+            "rel=${f#./}; "
+            "case \"$rel\" in "
+            "bin/*) d=\"/usr/bin/${rel#bin/}\"; mkdir -p \"$(dirname \"$d\")\"; mv -f \"$f\" \"$d\"; echo \"$d\" >> \"$DESTFILE\";; "
+            "lib/*) d=\"/usr/lib/${rel#lib/}\"; mkdir -p \"$(dirname \"$d\")\"; mv -f \"$f\" \"$d\"; echo \"$d\" >> \"$DESTFILE\";; "
+            "etc/*) d=\"/etc/pmm/%s/${rel#etc/}\"; mkdir -p \"$(dirname \"$d\")\"; mv -f \"$f\" \"$d\"; echo \"$d\" >> \"$DESTFILE\";; "
+            "usr/*) d=\"/usr/${rel#usr/}\"; mkdir -p \"$(dirname \"$d\")\"; mv -f \"$f\" \"$d\"; echo \"$d\" >> \"$DESTFILE\";; "
+            "*) d=\"/usr/share/pmm/%s/$rel\"; mkdir -p \"$(dirname \"$d\")\"; mv -f \"$f\" \"$d\"; echo \"$d\" >> \"$DESTFILE\";; "
+            "esac; done; ldconfig 2>/dev/null || true; "
+            "chmod -f +x /usr/bin/* >/dev/null 2>&1 || true",
+            destfile, root, pkg, pkg);
+        if (system(cmd2) != 0) {
+            pmm_warn("%s", pmm_tr_fmt("msg.warn.system-route", pkg));
+        }
+    }
+
     /* record file list + control in db */
     snprintf(cmd, sizeof(cmd), "%s/%s.info", db, pkg);
     FILE *dbf = fopen(cmd, "wb"); /* binary: keep \n, avoid Windows CRLF translation */
@@ -604,22 +632,33 @@ int pdm_install_file(const char *pdmfile) {
         fprintf(dbf, "Package: %s\nVersion: %s\nSource: %s\n\n%s\n",
                 pkg, ver ? ver : "0.0.0", base_name(pdmfile), ctl);
         fprintf(dbf, "Files:\n");
-        char ltcmd[2600];
+        if (sys_mode) {
-        snprintf(ltcmd, sizeof(ltcmd), "tar -tzf \"%s/data.tar.gz\"", stage);
+            FILE *df = fopen(destfile, "r");
-        FILE *tf = PMM_POPEN_READ(ltcmd);
+            if (df) {
-        if (tf) {
+                char ln[2048];
-            char ln[2048];
+                while (fgets(ln, sizeof(ln), df)) fputs(ln, dbf);
-            while (fgets(ln, sizeof(ln), tf)) {
+                fclose(df);
-                if (flat) { /* reflection of the flatten: strip a leading bin/ */
+            } else {
-                    const char *q = ln;
+                pmm_warn(pmm_tr("msg.warn.no-filelist"));
-                    while (*q==' '||*q=='\t') q++;
-                    if (q[0]=='.'&&q[1]=='/'&&strncasecmp(q+2,"bin/",4)==0) { ln[0]='\0'; continue; }
-                }
-                fputs(ln, dbf);
             }
-            PMM_PCLOSE_READ(tf);
         } else {
-            pmm_warn(pmm_tr("msg.warn.no-filelist"));
+            char ltcmd[2600];
+            snprintf(ltcmd, sizeof(ltcmd), "tar -tzf \"%s/data.tar.gz\"", stage);
+            FILE *tf = PMM_POPEN_READ(ltcmd);
+            if (tf) {
+                char ln[2048];
+                while (fgets(ln, sizeof(ln), tf)) {
+                    if (flat) { /* reflection of the flatten: strip a leading bin/ */
+                        const char *q = ln;
+                        while (*q==' '||*q=='\t') q++;
+                        if (q[0]=='.'&&q[1]=='/'&&strncasecmp(q+2,"bin/",4)==0) { ln[0]='\0'; continue; }
+                    }
+                    fputs(ln, dbf);
+                }
+                PMM_PCLOSE_READ(tf);
+            } else {
+                pmm_warn(pmm_tr("msg.warn.no-filelist"));
+            }
         }
         fclose(dbf);
     }
@@ -747,7 +786,8 @@ int pdm_remove(const char *name) {
                 char *p = path;
                 while (p[0] == '.' && p[1] == '/') p += 2;
                 char full[1200];
-                snprintf(full, sizeof(full), "%s/%s", root, p);
+                if (p[0] == '/') { snprintf(full, sizeof(full), "%s", p); }        /* system-mode absolute dest */
+                else snprintf(full, sizeof(full), "%s/%s", root, p);
                 remove(full);
                 n++;
             }

src/pmm.c

@@ -149,6 +149,16 @@ void pmm_set_install_path(const char *path) {
 }
 int pmm_flat_mode(void) { return g_base_path[0] ? 1 : 0; }
 
+/* System-install mode: unix default (no -p <path>). Writes to /usr/bin, /etc/pmm,
+ * the system lib dir and /usr/share/pmm — no PATH/LD_LIBRARY_PATH needed. */
+int pmm_system_mode(void) {
+#ifdef _WIN32
+    return 0;                     /* Windows always uses local mode */
+#else
+    return g_base_path[0] ? 0 : 1;
+#endif
+}
+
 /* Resolve the .pmm base dir: explicit drive override > persisted drive >
  * home/.pmm (when that drive is picked) > DEFAULT = D:\.pmm.
  * Defaulting to D:\ spares the C: drive (user's primary diskspace concern);
@@ -188,7 +198,7 @@ static const char *pmm_base_dir(char *buf, size_t size) {
 #ifdef _WIN32
         snprintf(buf, size, "D:\\.pmm");                      /* Windows DEFAULT -> D: */
 #else
-        snprintf(buf, size, "%s/.pmm", home_dir());           /* unix default -> ~/.pmm */
+        snprintf(buf, size, "/etc/pmm");                      /* unix default -> system config dir */
 #endif
     }
     return buf;
@@ -201,6 +211,7 @@ const char *pmm_config_dir(char *buf, size_t size) {
 }
 
 const char *pmm_cache_dir(char *buf, size_t size) {
+    if (pmm_system_mode()) { snprintf(buf, size, "/var/cache/pmm"); mkdir_p(buf); return buf; }
     char base[1024];
     pmm_base_dir(base, sizeof(base));
     snprintf(buf, size, "%s/cache", base);
@@ -219,7 +230,7 @@ const char *pmm_install_dir(char *buf, size_t size) {
         pmm_base_dir(base, sizeof(base));
         snprintf(buf, size, "%s/bin", base);      /* Windows default -> <base>\bin */
 #else
-        snprintf(buf, size, "/usr/local/bin");     /* Linux/macOS default -> system-wide (on PATH) */
+        snprintf(buf, size, "/usr/bin");           /* Linux/macOS default -> system-wide (on PATH) */
 #endif
     }
     mkdir_p(buf);
@@ -300,6 +311,7 @@ static void add_path_candidate(char list[][1200], int *n, int max, const char *d
 }
 
 void pmm_add_to_path(void) {
+    if (pmm_system_mode()) return;   /* system mode: /usr/bin & system libs are already found */
     char home[1024];
     pmm_config_dir(home, sizeof(home));
     char base[1024];

src/pmm.h

@@ -27,6 +27,10 @@ void pmm_set_install_path(const char *path);
  * into that directory (files flattened), without a root/bin sub-folder. */
 int pmm_flat_mode(void);
 
+/* 1 if running in system-install mode (unix default, no -p): files go to
+ * /usr/bin, /etc/pmm, the system lib dir; no PATH/LD_LIBRARY_PATH is written. */
+int pmm_system_mode(void);
+
 /* File-association record written to the per-user registry on install. */
 typedef struct {
     const char *progid;    /* e.g. "Node.JSFile" */

web/mirror/lang/en-US.pjson

@@ -137,5 +137,6 @@
   "msg.err.not-cached": "%s not in cache (run pmm fetch)",
   "msg.postinst-ok": "post-install script ran OK: %s",
   "msg.warn.postinst": "post-install script returned non-zero: %s",
-  "msg.warn.postinst-missing": "post-install script missing: %s"
+  "msg.warn.postinst-missing": "post-install script missing: %s",
+  "msg.warn.system-route": "some files failed to route to system paths: %s"
 }

web/mirror/lang/zh-CN.pjson

@@ -137,5 +137,6 @@
   "msg.err.not-cached": "%s 未在缓存中（先运行 pmm fetch）",
   "msg.postinst-ok": "安装后脚本执行成功: %s",
   "msg.warn.postinst": "安装后脚本返回非 0: %s",
-  "msg.warn.postinst-missing": "安装后脚本缺失: %s"
+  "msg.warn.postinst-missing": "安装后脚本缺失: %s",
+  "msg.warn.system-route": "安装后路由到系统路径时部分失败: %s"
 }