Directory listing in userspace

kernel/fs/fat16.cpp

@@ -127,10 +127,10 @@ namespace FS
         } while ((cluster = NextCluster(cluster)) != FAT_END);
     }
 
-    void Fat16::ListDirectory(const nk::String &path)
+    nk::Vector<DirEntry> Fat16::ListDirectory(const nk::String &path)
     {
-        printf("List of %s:\n", path.CStr());
-
+        nk::Vector<DirEntry> result;
+        result.EnsureCapacity(16);
         auto directory = LoadDirectory(path);
 
         bool eof = false;
@@ -140,15 +140,9 @@ namespace FS
             if (eof)
                 break;
 
-            if (entry.type == DirEntryType::File)
-            {
-                printf(" [f] %s\n", entry.name.CStr());
-            }
-            else if (entry.type == DirEntryType::Folder)
-            {
-                printf(" [d] %s\n", entry.name.CStr());
-            }
+            result.Add(entry);
         }
+        return result;
     }
 
     uint8_t *Fat16::LoadDirectory(const nk::Path &path)

kernel/fs/vfs.cpp

@@ -108,18 +108,15 @@ namespace FS
         }
     }
 
-    void VirtualFileSystem::ListDirectory(const nk::String &path)
+    nk::Vector<DirEntry> VirtualFileSystem::ListDirectory(const nk::String &path)
     {
         auto mountPoint = FindMountPoint(path);
         if (mountPoint == nullptr)
         {
             kdbg("vfs: Mount point not found for %s\n", path.CStr());
-            return;
+            return {};
         }
-#if VFS_DEBUG
-        kdbg("vfs: list_dir %s\n", mountPoint->path.CStr());
-#endif
-        mountPoint->fs->ListDirectory(GetRelativePath(mountPoint, path));
+        return mountPoint->fs->ListDirectory(GetRelativePath(mountPoint, path));
     }
 
     nk::String VirtualFileSystem::GetRelativePath(MountPoint *mountPoint, const nk::String &absolutePath)

kernel/include/kernel/fs/fat16.h

@@ -38,7 +38,7 @@ namespace FS
 
         void Read(const DirEntry &entry, size_t offset, size_t size, uint8_t *dst) override;
 
-        void ListDirectory(const nk::String &path) override;
+        nk::Vector<DirEntry> ListDirectory(const nk::String &path) override;
 
     private:
         uint8_t *LoadDirectory(const nk::Path &path);

kernel/include/kernel/fs/filesystem.h

@@ -5,6 +5,7 @@
 #include <kernel/fs/partition.h>
 #include <kernel/fs/direntry.h>
 #include <nk/string.h>
+#include <nk/vector.h>
 
 namespace FS
 {
@@ -26,7 +27,7 @@ namespace FS
 
         virtual void Read(const DirEntry &entry, size_t offset, size_t size, uint8_t *dst) = 0;
 
-        virtual void ListDirectory(const nk::String &path) = 0;
+        virtual nk::Vector<DirEntry> ListDirectory(const nk::String &path) = 0;
     };
 
 } // namespace FS

kernel/include/kernel/fs/vfs.h

@@ -37,7 +37,7 @@ namespace FS
 
         void Close(uint32_t fileHandle);
 
-        void ListDirectory(const nk::String &path);
+        nk::Vector<DirEntry> ListDirectory(const nk::String &path);
 
     private:
         nk::String GetRelativePath(MountPoint *mountPoint, const nk::String &absolutePath);

kernel/include/kernel/syscalls.h

@@ -4,6 +4,7 @@
 #include <sys/types.h>
 #include <stddef.h>
 #include <stdint.h>
+#include <dirent.h>
 
 #define SYS_INVAL 0
 #define SYS_TEXIT 1
@@ -25,6 +26,7 @@
 #define SYS_CHDIR 17
 #define SYS_GETCWD 18
 #define SYS_GETENV 19
+#define SYS_READDIR 20
 
 #define PARAM_VALUE(param, type) (*(type *)(param))
 
@@ -94,6 +96,13 @@ extern "C"
         char *val;
     } sys$$getenv_param;
 
+    typedef struct
+    {
+        const char *dir;
+        dirent *dst;
+        size_t dstSize;
+    } sys$$readdir_param;
+
 #ifdef __cplusplus
 }
 #endif
@@ -117,5 +126,6 @@ int sys$$fb_release(void *param);
 int sys$$chdir(void *param);
 int sys$$getcwd(void *param);
 int sys$$getenv(void *param);
+int sys$$readdir(void *param);
 
 #endif

kernel/syscallhandler.cpp

@@ -38,6 +38,7 @@ namespace Kernel
         AddSyscall(SYS_CHDIR, sys$$chdir);
         AddSyscall(SYS_GETCWD, sys$$getcwd);
         AddSyscall(SYS_GETENV, sys$$getenv);
+        AddSyscall(SYS_READDIR, sys$$readdir);
         Interrupts::AddHandler(0x80, this);
     }
 

kernel/syscalls.cpp

@@ -239,4 +239,26 @@ int sys$$getenv(void *param)
         return -EINVAL;
     memcpy(params->val, val.CStr(), val.Length());
     return 0;
+}
+
+int sys$$readdir(void *param)
+{
+    sys$$readdir_param *params = (sys$$readdir_param *)param;
+    auto dirent = FS::VirtualFileSystem::GetInstance()->GetFileMeta(params->dir);
+    if (!dirent.IsValid())
+        return -ENOENT;
+    if (dirent.type != FS::DirEntryType::Folder)
+        return -ENOTDIR;
+
+    auto dir = FS::VirtualFileSystem::GetInstance()->ListDirectory(params->dir);
+    size_t maxSize = dir.Size() > params->dstSize ? params->dstSize : dir.Size();
+    for (size_t i = 0; i < maxSize; i++)
+    {
+        auto src = dir[i];
+        auto &dst = params->dst[i];
+        memcpy(dst.name, src.name.CStr(), src.name.Length() + 1);
+        dst.size = src.size;
+        dst.type = static_cast<unsigned>(src.type);
+    }
+    return maxSize;
 }

libc/dirent.c

@@ -0,0 +1,35 @@
+#include <sys/syscall.h>
+#include <dirent.h>
+
+DIR *opendir(const char *name)
+{
+    DIR *dir = malloc(sizeof(DIR));
+    dir->idx = 0;
+
+    sys$$readdir_param param;
+    param.dir = name;
+    param.dst = dir->data;
+    param.dstSize = 256;
+    int result = syscall(SYS_READDIR, &param);
+    if (result < 0)
+    {
+        free(dir);
+        return NULL;
+    }
+    dir->max = result;
+    return dir;
+}
+
+int closedir(DIR *dir)
+{
+    free(dir);
+}
+
+dirent *readdir(DIR *dir)
+{
+    if (dir->idx >= dir->max)
+        return NULL;
+    dirent *d = &dir->data[dir->idx];
+    dir->idx++;
+    return d;
+}

libc/include/dirent.h

@@ -0,0 +1,36 @@
+#ifndef _DIRENT_H
+#define _DIRENT_H
+
+#include <stddef.h>
+
+#ifdef __cplusplus
+extern "C"
+{
+#endif
+
+#define TYPE_FILE 0
+#define TYPE_DIR 1
+
+    typedef struct
+    {
+        char name[256];
+        size_t size;
+        unsigned type;
+    } dirent;
+
+    typedef struct
+    {
+        dirent data[256];
+        size_t idx;
+        size_t max;
+    } DIR;
+
+    DIR *opendir(const char *name);
+    int closedir(DIR *);
+    dirent *readdir(DIR *);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif

userland/ls/main.cpp

@@ -2,18 +2,38 @@
 #include <stdio.h>
 #include <unistd.h>
 #include <stdlib.h>
+#include <dirent.h>
 
-int main(int argc, char **argv)
+void printdir(const char *path)
 {
-    char *p = getenv("Path");
-    printf("path env: %s\n", p);
-    free(p);
+    DIR *dir = opendir(path);
+
+    dirent *ent;
+    while ((ent = readdir(dir)) != NULL)
+    {
+        if (ent->type == TYPE_DIR)
+        {
+            printf("[d] %s\n", ent->name);
+        }
+        else if (ent->type == TYPE_FILE)
+        {
+            printf("[f] [%d B] %s\n", ent->size, ent->name);
+        }
+    }
 
-    char cwd[PATH_MAX];
-    getcwd(cwd, PATH_MAX);
+    closedir(dir);
+}
 
-    printf("Running ls with %d args\n", argc);
-    printf(" CWD: %s\n", cwd);
-    if (argc != 0)
-        printf("Args[0] %s\n", argv[0]);
+int main(int argc, char **argv)
+{
+    if (argc == 0)
+    {
+        char cwd[PATH_MAX];
+        getcwd(cwd, PATH_MAX);
+        printdir(cwd);
+    }
+    else
+    {
+        printdir(argv[0]);
+    }
 }