Hyperion v1.2.0

Src/Hyperion-bash/bin/chattr

@@ -0,0 +1,162 @@
+--:Minify:--
+-- supports +i/-i (immutable) stored in the file's cmeta/xattr field
+local name = syscall.getTask(syscall.getpid()).name
+local cloptions = { R = false, help = false }
+local args = {}
+local modeStr = nil
+
+for _, v in ipairs({ ... }) do
+    if v:sub(1, 2) == "--" then
+        local opt = v:sub(3)
+        if cloptions[opt] == nil then
+            print(name .. ": unrecognized option '" .. v .. "'")
+            print("try '" .. name .. " --help' for more information.")
+            syscall.exit(1); return
+        end
+        cloptions[opt] = true
+    elseif v:sub(1, 1) == "-" and not v:match("^%-[%+%-]") then
+        local isFlag = true
+        for i = 2, #v do
+            local c = v:sub(i,i)
+            if cloptions[c] ~= nil then
+                cloptions[c] = true
+            else
+                isFlag = false; break
+            end
+        end
+        if not isFlag then
+            modeStr = v
+        end
+    elseif v:sub(1,1) == "+" or (v:sub(1,1) == "-" and v:match("^%-[a-zA-Z]")) then
+        modeStr = v
+    else
+        table.insert(args, v)
+    end
+end
+
+if cloptions.help then
+    print("Usage: " .. name .. " [OPTION]... +-= ATTRS FILE...")
+    print("Change file attributes on a filesystem.")
+    print("")
+    print("Attributes:")
+    print("  i    immutable: file cannot be modified, renamed, or deleted")
+    print("  a    append-only: file can only be appended to")
+    print("")
+    print("Operators:  +attr  add,  -attr  remove")
+    print("Example:  " .. name .. " +i /etc/passwd")
+    print("")
+    print("Options:")
+    print("  -R          operate on files and directories recursively")
+    print("  --help      display this help and exit")
+    return
+end
+
+if not modeStr or #args < 1 then
+    print(name .. ": missing operand")
+    print("try '" .. name .. " --help' for more information.")
+    syscall.exit(1); return
+end
+
+local op    = modeStr:sub(1, 1)
+local attrs = modeStr:sub(2)
+
+if op ~= "+" and op ~= "-" then
+    print(name .. ": invalid operator '" .. op .. "' (use + or -)")
+    syscall.exit(1); return
+end
+
+local function getXattr(path)
+    local stat = pcall(function() return syscall.stat(path) end) and syscall.stat(path)
+    if stat then return stat.xattr or "" end
+    return ""
+end
+
+local IMMUTABLE_TAG  = "|i"
+local APPENDONLY_TAG = "|a"
+
+local function attrTag(c)
+    if c == "i" then return IMMUTABLE_TAG
+    elseif c == "a" then return APPENDONLY_TAG
+    else return nil end
+end
+
+local function chattrPath(path)
+    local stat = syscall.stat(path)
+    if not stat then
+        print(name .. ": cannot stat '" .. path .. "': No such file or directory")
+        return false
+    end
+    if stat.etype == 0x01 then
+        return true
+    end
+
+    if not syscall.setxattr then
+        print(name .. ": kernel does not expose setxattr syscall; cannot modify attributes")
+        syscall.exit(1); return false
+    end
+
+    local xattr = stat.xattr or ""
+
+    for i = 1, #attrs do
+        local c = attrs:sub(i, i)
+        local tag = attrTag(c)
+        if not tag then
+            print(name .. ": unsupported attribute '" .. c .. "'")
+            syscall.exit(1); return false
+        end
+        local hasTag = xattr:find(tag, 1, true)
+        if op == "+" and not hasTag then
+            xattr = xattr .. tag
+        elseif op == "-" and hasTag then
+            xattr = xattr:gsub(tag:gsub("|", "%%|"), "")
+        end
+    end
+
+    local ok, err = pcall(syscall.setxattr, path, xattr)
+    if not ok then
+        print(name .. ": cannot set attributes on '" .. path .. "': " .. tostring(err))
+        return false
+    end
+    return true
+end
+
+local function chattrRecursive(path)
+    if not chattrPath(path) then return end
+    if syscall.type(path) == "directory" then
+        local ok, list = pcall(syscall.listdir, path)
+        if ok then
+            for _, entry in ipairs(list) do
+                local child = path
+                if child:sub(-1) ~= "/" then child = child .. "/" end
+                chattrRecursive(child .. entry)
+            end
+        end
+    end
+end
+
+local cwd = syscall.getcwd()
+local function absPath(p)
+    if p:sub(1,1) ~= "/" then p = cwd .. "/" .. p end
+    return p
+end
+
+if not syscall.setxattr then
+    print(name .. ": kernel does not expose setxattr; attributes cannot be persisted")
+    print(name .. ": add  sys[\"setxattr\"] = vfs.setxattr  to 10_vfs.kmod to enable this")
+    syscall.exit(1); return
+end
+
+local exitCode = 0
+for i = 1, #args do
+    local path = absPath(args[i])
+    if not syscall.exists(path) then
+        print(name .. ": cannot access '" .. args[i] .. "': No such file or directory")
+        exitCode = 1
+    elseif cloptions.R then
+        chattrRecursive(path)
+    else
+        if not chattrPath(path) then exitCode = 1 end
+    end
+end
+
+syscall.exit(exitCode)