Support excluding firmlinks on macOS

configure.ac

@@ -30,6 +30,11 @@ AC_CHECK_FUNCS(
 
 AC_CHECK_FUNCS(statfs)
 
+AC_CHECK_HEADERS([sys/attr.h])
+
+AC_CHECK_FUNCS([getattrlist])
+
+AC_CHECK_DECLS([ATTR_CMNEXT_NOFIRMLINKPATH], [], [], [[#include <sys/attr.h>]])
 
 # Look for ncurses library to link to
 ncurses=auto

src/browser.c

@@ -119,6 +119,7 @@ static void browse_draw_flag(struct dir *n, int *x) {
        n->flags & FF_SERR ? '.' :
       n->flags & FF_OTHFS ? '>' :
      n->flags & FF_KERNFS ? '^' :
+     n->flags & FF_FRMLNK ? 'F' :
       n->flags & FF_HLNKC ? 'H' :
      !(n->flags & FF_FILE
     || n->flags & FF_DIR) ? '@' :

src/dir_export.c

@@ -116,7 +116,7 @@ static void output_info(struct dir *d, const char *name, struct dir_ext *e) {
   if(d->flags & FF_ERR)
     fputs(",\"read_error\":true", stream);
   /* excluded/error'd files are "unknown" with respect to the "notreg" field. */
-  if(!(d->flags & (FF_DIR|FF_FILE|FF_ERR|FF_EXL|FF_OTHFS|FF_KERNFS)))
+  if(!(d->flags & (FF_DIR|FF_FILE|FF_ERR|FF_EXL|FF_OTHFS|FF_KERNFS|FF_FRMLNK)))
     fputs(",\"notreg\":true", stream);
   if(d->flags & FF_EXL)
     fputs(",\"excluded\":\"pattern\"", stream);
@@ -124,6 +124,8 @@ static void output_info(struct dir *d, const char *name, struct dir_ext *e) {
     fputs(",\"excluded\":\"othfs\"", stream);
   else if(d->flags & FF_KERNFS)
     fputs(",\"excluded\":\"kernfs\"", stream);
+  else if(d->flags & FF_FRMLNK)
+    fputs(",\"excluded\":\"frmlnk\"", stream);
 
   fputc('}', stream);
 }

src/dir_import.c

@@ -482,6 +482,8 @@ static int iteminfo(void) {
         ctx->buf_dir->flags |= FF_OTHFS;
       else if(strcmp(ctx->val, "kernfs") == 0)
         ctx->buf_dir->flags |= FF_KERNFS;
+      else if(strcmp(ctx->val, "frmlnk") == 0)
+        ctx->buf_dir->flags |= FF_FRMLNK;
       else
         ctx->buf_dir->flags |= FF_EXL;
     } else if(strcmp(ctx->val, "notreg") == 0) {     /* notreg */

src/dir_scan.c

@@ -34,6 +34,10 @@
 #include <sys/stat.h>
 #include <dirent.h>
 
+#if HAVE_SYS_ATTR_H && HAVE_GETATTRLIST && HAVE_DECL_ATTR_CMNEXT_NOFIRMLINKPATH
+#include <sys/attr.h>
+#endif
+
 #if HAVE_LINUX_MAGIC_H && HAVE_SYS_STATFS_H && HAVE_STATFS
 #include <sys/statfs.h>
 #include <linux/magic.h>
@@ -241,6 +245,25 @@ static int dir_scan_item(const char *name) {
   }
 #endif
 
+#if HAVE_SYS_ATTR_H && HAVE_GETATTRLIST && HAVE_DECL_ATTR_CMNEXT_NOFIRMLINKPATH
+  if(!follow_firmlinks) {
+    struct attrlist list = {
+      .bitmapcount = ATTR_BIT_MAP_COUNT,
+      .forkattr = ATTR_CMNEXT_NOFIRMLINKPATH,
+    };
+    struct {
+      uint32_t length;
+      attrreference_t reference;
+      char extra[PATH_MAX];
+    } __attribute__((aligned(4), packed)) attributes;
+    if (getattrlist(name, &list, &attributes, sizeof(attributes), FSOPT_ATTR_CMN_EXTENDED) == -1) {
+      buf_dir->flags |= FF_ERR;
+      dir_setlasterr(dir_curpath);
+    } else if (strcmp(dir_curpath, (char *)&attributes.reference + attributes.reference.attr_dataoffset))
+      buf_dir->flags |= FF_FRMLNK;
+  }
+#endif
+
   if(!(buf_dir->flags & (FF_ERR|FF_EXL))) {
     if(follow_symlinks && S_ISLNK(st.st_mode) && !stat(name, &stl) && !S_ISDIR(stl.st_mode))
       stat_to_dir(&stl);
@@ -248,14 +271,14 @@ static int dir_scan_item(const char *name) {
       stat_to_dir(&st);
   }
 
-  if(cachedir_tags && (buf_dir->flags & FF_DIR) && !(buf_dir->flags & (FF_ERR|FF_EXL|FF_OTHFS|FF_KERNFS)))
+  if(cachedir_tags && (buf_dir->flags & FF_DIR) && !(buf_dir->flags & (FF_ERR|FF_EXL|FF_OTHFS|FF_KERNFS|FF_FRMLNK)))
     if(has_cachedir_tag(name)) {
       buf_dir->flags |= FF_EXL;
       buf_dir->size = buf_dir->asize = 0;
     }
 
   /* Recurse into the dir or output the item */
-  if(buf_dir->flags & FF_DIR && !(buf_dir->flags & (FF_ERR|FF_EXL|FF_OTHFS|FF_KERNFS)))
+  if(buf_dir->flags & FF_DIR && !(buf_dir->flags & (FF_ERR|FF_EXL|FF_OTHFS|FF_KERNFS|FF_FRMLNK)))
     fail = dir_scan_recurse(name);
   else if(buf_dir->flags & FF_DIR) {
     if(dir_output.item(buf_dir, name, buf_ext) || dir_output.item(NULL, 0, NULL)) {

src/global.h

@@ -52,6 +52,7 @@
 #define FF_BSEL    0x80 /* selected */
 #define FF_EXT    0x100 /* extended struct available */
 #define FF_KERNFS 0x200 /* excluded because it was a Linux pseudo filesystem */
+#define FF_FRMLNK 0x400 /* excluded because it was a firmlink */
 
 /* Program states */
 #define ST_CALC   0
@@ -106,6 +107,8 @@ extern int confirm_quit;
 extern int extended_info;
 /* flag whether we want to follow symlinks */
 extern int follow_symlinks;
+/* flag whether we want to follow firmlinks */
+extern int follow_firmlinks;
 
 /* handle input from keyboard and update display */
 int input_handle(int);

src/main.c

@@ -42,6 +42,7 @@ long update_delay = 100;
 int cachedir_tags = 0;
 int extended_info = 0;
 int follow_symlinks = 0;
+int follow_firmlinks = 0;
 int confirm_quit = 0;
 
 static int min_rows = 17, min_cols = 60;
@@ -138,6 +139,7 @@ static void argv_parse(int argc, char **argv) {
     { 'L', 0, "-L,--follow-symlinks" },
     { 'C', 0, "--exclude-caches" },
     {  2,  0, "--exclude-kernfs" },
+    {  3,  0, "--follow-firmlinks" },
     { 's', 0, "--si" },
     { 'Q', 0, "--confirm-quit" },
     { 'c', 1, "--color" },
@@ -169,6 +171,9 @@ static void argv_parse(int argc, char **argv) {
       printf("  --exclude-caches           Exclude directories containing CACHEDIR.TAG\n");
 #if HAVE_LINUX_MAGIC_H && HAVE_SYS_STATFS_H && HAVE_STATFS
       printf("  --exclude-kernfs           Exclude Linux pseudo filesystems (procfs,sysfs,cgroup,...)\n");
+#endif
+#if HAVE_SYS_ATTR_H && HAVE_GETATTRLIST && HAVE_DECL_ATTR_CMNEXT_NOFIRMLINKPATH
+      printf("  --follow-firmlinks         Follow firmlinks on macOS\n");
 #endif
       printf("  --confirm-quit             Confirm quitting ncdu\n");
       printf("  --color SCHEME             Set color scheme (off/dark)\n");
@@ -205,6 +210,13 @@ static void argv_parse(int argc, char **argv) {
 #else
       fprintf(stderr, "This feature is not supported on your platform\n");
       exit(1);
+#endif
+    case  3 :
+#if HAVE_SYS_ATTR_H && HAVE_GETATTRLIST && HAVE_DECL_ATTR_CMNEXT_NOFIRMLINKPATH
+      follow_firmlinks = 1; break;
+#else
+      fprintf(stderr, "This feature is not supported on your platform\n");
+      exit(1);
 #endif
     case 'c':
       if(strcmp(val, "off") == 0)  { uic_theme = 0; }