feat: fs tree and free list alloc

1 files changed, 98 insertions, 12 deletions

diff --git a/kernel/shell.rv b/kernel/shell.rv
index f72387a..40930c5 100644
--- a/kernel/shell.rv
+++ b/kernel/shell.rv
@@ -19,10 +19,14 @@ fn cmd_help() do
   help_row("zoom in|out", "scale the font")
   help_row("echo <text>", "print it back")
   puts("\n  files\n")
-  help_row("ls", "list files")
-  help_row("cat <name>", "print a file")
-  help_row("write <name> <text>", "create or overwrite")
-  help_row("rm <name>", "delete a file")
+  help_row("ls [path]", "list a directory")
+  help_row("cd <path>", "change directory")
+  help_row("pwd", "print working dir")
+  help_row("mkdir <path>", "make a directory")
+  help_row("cat <path>", "print a file")
+  help_row("edit <path>", "line editor, . to save")
+  help_row("write <path> <text>", "create or overwrite")
+  help_row("rm <path>", "delete a file or empty dir")
   help_row("mkfs", "format the disk")
   puts("\n  programs\n")
   help_row("run", "list programs")
@@ -34,7 +38,7 @@ fn welcome() do
   let fsline = "no filesystem"
   if fs.ready do fsline = "revelfs mounted" end
   puts("\n")
-  puts("   a tiny os whose brain lives in revo, zig only touches the metal\n")
+  puts("   kernel written in revo - by an alcoholic\n")
   puts("   #{(mem_total() shr 20)} MiB ram | #{fsline} | #{prog_count()} programs\n")
   puts("   type help to see what it does\n\n% ")
 end
@@ -43,7 +47,6 @@ fn arg_name(line, start) do
   let quoted = :false
   let begin = start
   if (begin < line:len() and line[begin] == "\"") do begin += 1 quoted = :true end
-  # scan to the end of the name, a closing quote or a space depending on how it opened
   let i = begin
   if quoted do
     while (i < line:len() and line[i] != "\"") do i += 1 end
@@ -52,29 +55,103 @@ fn arg_name(line, start) do
     while (i < line:len() and line[i] != " ") do i += 1 end
   end
   const name = line[begin..i]
-  # step past the closing quote and the separating space so rest points at the text
   let rest = i
   if (quoted and rest < line:len()) do rest += 1 end
   if (rest < line:len() and line[rest] == " ") do rest += 1 end
   { name = name, rest = rest }
 end
 
+global wd = { path = "/" }
+
+global editor = { active = :false, path = "", buf = "" }
+
+fn editor_start(path) do
+  editor.active = :true
+  editor.path = path
+  editor.buf = ""
+  const sz = fs:size(path)
+  if sz > 0 do
+    editor.buf = fs:read_bytes(path, 0, sz)
+    puts(editor.buf)
+  end
+  puts("-- editing #{path}, a single . on a line saves and exits --\n")
+end
+
+fn editor_line(line) do
+  if line == "." do
+    fs:store(editor.path, editor.buf)
+    editor.active = :false
+    puts("saved #{editor.path} (#{editor.buf:len()} bytes)\n% ")
+  end
+  else do editor.buf = editor.buf ~ line ~ "\n" end
+end
+
+fn cmd_edit(line) do
+  const a = arg_name(line, 5)
+  if a.name:len() == 0 do puts("usage: edit <path>\n% ") return :nil end
+  editor_start(abspath(a.name))
+end
+
+fn abspath(arg) do
+  if arg:len() == 0 return wd.path
+  let p = arg
+  if arg[0] != "/" do
+    if wd.path == "/" do p = "/#{arg}" end
+    else do p = "#{wd.path}/#{arg}" end
+  end
+  while (p:len() > 1 and p[p:len() - 1] == "/") do p = p[0..(p:len() - 1)] end
+  return p
+end
+
+fn parent_of(path) do
+  if path == "/" return "/"
+  let i = path:len() - 1
+  while (i > 0 and path[i] != "/") do i -= 1 end
+  if i == 0 return "/"
+  return path[0..i]
+end
+
+fn cmd_cd(words) do
+  const arg = if words:len() > 1 words[1] else "/"
+  const target = if arg == ".." parent_of(wd.path) else abspath(arg)
+  if target == "/proc" or target == "/bin" or fs:is_dir(target) do wd.path = target end
+  else do puts("cd: #{arg}: not a directory\n") end
+end
+
+fn cmd_pwd() puts("#{wd.path}\n")
+
+fn cmd_ls(words) do
+  const target = if words:len() > 1 abspath(words[1]) else wd.path
+  if vfs_owns(target) do vfs_ls(target) return :nil end
+  const n = fs:ls(target)
+  # the virtual mounts arent real dir entries, overlay them on the root listing
+  if target == "/" do puts("  bin/\n  proc/\n") end
+  else if n == 0 do puts("  (empty)\n") end
+end
+
+fn cmd_mkdir(words) do
+  if words:len() < 2 do puts("usage: mkdir <name>\n") return :nil end
+  fs:mkdir(abspath(words[1]))
+end
+
 fn cmd_write(line) do
   const a = arg_name(line, 6)
   if a.name:len() == 0 do puts("usage: write <name> <text>\n") return :nil end
-  fs:write(a.name, line[a.rest..])
+  fs:write(abspath(a.name), line[a.rest..])
 end
 
 fn cmd_cat(line) do
   const a = arg_name(line, 4)
   if a.name:len() == 0 do puts("usage: cat <name>\n") return :nil end
-  fs:cat(a.name)
+  const p = abspath(a.name)
+  if vfs_owns(p) do vfs_cat(p) return :nil end
+  fs:cat(p)
 end
 
 fn cmd_rm(line) do
   const a = arg_name(line, 3)
   if a.name:len() == 0 do puts("usage: rm <name>\n") return :nil end
-  fs:rm(a.name)
+  fs:rm(abspath(a.name))
 end
 
 fn zoom_by(delta) do
@@ -136,12 +213,18 @@ fn cmd_uptime() puts("#{math.floor(uptime() / 100)}s (#{uptime()} ticks)\n")
 fn cmd_ps() puts("#{proc_count()} process(es) running\n")
 
 fn run(line) do
+  if editor.active do editor_line(line) return :nil end
   if line:trim():len() == 0 do puts("% ") return :nil end
   const words = line:split(" ")
   const cmd = words[0]
+  if cmd == "edit" do cmd_edit(line) return :nil end
   if cmd == "run" do
     if words:len() <= 1 do list_progs() puts("% ") return :nil end
-    if run_prog(words[1]) == :true return :nil
+    const prog = words[1]
+    # everything after "run <prog> " is the programs argument string
+    const start = 4 + prog:len() + 1
+    const arg = if line:len() > start line[start..] else ""
+    if run_prog(prog, arg) == :true return :nil
     puts("% ")
     return :nil
   end
@@ -154,10 +237,13 @@ fn run(line) do
     | "ps" => cmd_ps()
     | "zoom" => cmd_zoom(words)
     | "mkfs" => fs:format()
-    | "ls" => fs:ls()
+    | "ls" => cmd_ls(words)
     | "cat" => cmd_cat(line)
     | "write" => cmd_write(line)
     | "rm" => cmd_rm(line)
+    | "mkdir" => cmd_mkdir(words)
+    | "cd" => cmd_cd(words)
+    | "pwd" => cmd_pwd()
     | "echo" => if line:len() > 5 puts("#{line[5..]}\n") else puts("\n")
     | _ => puts("unknown command: #{cmd}\n")
   puts("% ")