libluna: Add String::from_string_view()

apps/ls.cpp

@@ -1,12 +1,18 @@
 #include <os/ArgumentParser.h>
 #include <os/Directory.h>
 #include <os/File.h>
+#include <os/FileSystem.h>
+
+#include <fcntl.h>
+#include <stdio.h>
+#include <sys/stat.h>
 
 Result<int> luna_main(int argc, char** argv)
 {
     StringView pathname;
     bool show_all { false };
     bool show_almost_all { false };
+    bool long_list { false };
 
     os::ArgumentParser parser;
     parser.add_description("List files contained in a directory (defaults to '.', the current directory)"_sv);
@@ -14,19 +20,51 @@ Result<int> luna_main(int argc, char** argv)
     parser.add_positional_argument(pathname, "directory"_sv, "."_sv);
     parser.add_switch_argument(show_all, 'a', "all"_sv, "also list hidden files (whose filename begins with a dot)"_sv);
     parser.add_switch_argument(show_almost_all, 'A', "almost-all"_sv, "list all files except '.' and '..'"_sv);
+    parser.add_switch_argument(long_list, 'l', ""_sv, "use a long listing format"_sv);
     parser.parse(argc, argv);
 
-    auto dir = TRY(os::Directory::open(pathname));
+    Vector<String> files;
+    int dirfd = AT_FDCWD;
+    SharedPtr<os::Directory> dir;
+
+    if (os::FileSystem::is_directory(pathname))
+    {
+        dir = TRY(os::Directory::open(pathname));
+        dirfd = dir->fd();
 
         auto filter = os::Directory::Filter::Hidden;
         if (show_almost_all) filter = os::Directory::Filter::ParentAndBase;
         else if (show_all)
             filter = os::Directory::Filter::None;
 
-    auto files = TRY(dir->list(filter));
+        files = TRY(dir->list(filter));
+    }
+    else
+    {
+        auto str = TRY(String::from_string_view(pathname));
+        TRY(files.try_append(move(str)));
+    }
 
+    if (!long_list)
+    {
         auto list = TRY(String::join(files, " "_sv));
         os::println("%s", list.chars());
+    }
+    else
+    {
+        for (const auto& file : files)
+        {
+            struct stat st;
+            if (fstatat(dirfd, file.chars(), &st, 0) < 0)
+            {
+                perror(file.chars());
+                return 1;
+            }
+
+            os::println("%6o %u %4u %4u %10lu %s", st.st_mode, st.st_nlink, st.st_uid, st.st_gid, st.st_size,
+                        file.chars());
+        }
+    }
 
     return 0;
 }

libc/include/bits/modes.h

@@ -8,9 +8,11 @@
 #define S_IFDIR 040000
 #define S_IFCHR 050000
 
-#define S_ISREG(mode) ((mode)&S_IFMT == S_IFREG)
+#define __CHECK_TYPE(mode, type) (((mode)&S_IFMT) == type)
-#define S_ISDIR(mode) ((mode)&S_IFMT == S_IFDIR)
+
-#define S_ISCHR(mode) ((mode)&S_IFMT == S_IFCHR)
+#define S_ISREG(mode) __CHECK_TYPE(mode, S_IFREG)
+#define S_ISDIR(mode) __CHECK_TYPE(mode, S_IFDIR)
+#define S_ISCHR(mode) __CHECK_TYPE(mode, S_IFCHR)
 
 #define S_IRWXU 0700
 #define S_IRUSR 0400

libc/include/sys/stat.h

@@ -29,6 +29,9 @@ extern "C"
     /* Retrieve information about a file. */
     int fstat(int fd, struct stat* st);
 
+    /* Retrieve information about a file. */
+    int fstatat(int dirfd, const char* path, struct stat* st, int flags);
+
 #ifdef __cplusplus
 }
 #endif

libc/src/sys/stat.cpp

@@ -29,4 +29,10 @@ extern "C"
         long rc = syscall(SYS_fstatat, fd, "", st, AT_EMPTY_PATH);
         __errno_return(rc, int);
     }
+
+    int fstatat(int dirfd, const char* path, struct stat* st, int flags)
+    {
+        long rc = syscall(SYS_fstatat, dirfd, path, st, flags);
+        __errno_return(rc, int);
+    }
 }

libluna/include/luna/String.h

@@ -41,6 +41,10 @@ class String
     static Result<String> vformat(StringView fmt, va_list ap);
 
     static Result<String> from_cstring(const char* str);
+    static Result<String> from_string_view(StringView str)
+    {
+        return from_cstring(str.chars());
+    }
 
     const char* chars() const
     {