> ## Documentation Index
> Fetch the complete documentation index at: https://kernel.mvhcloud.com/llms.txt
> Use this file to discover all available pages before exploring further.
# MVH Kernel Filesystem Shell Commands — Full Reference
> Reference for all filesystem shell commands: ls, cd, pwd, mkdir, touch, write, append, cat, rm, rmdir, mount, and df. Includes usage examples.
MVH Kernel mounts a RAMFS (RAM-based filesystem) as the root filesystem at boot. The filesystem lives entirely in kernel memory, so it is fast and requires no disk hardware, but it is completely **volatile** — every file and directory you create is lost the moment you reboot. Use it to hold temporary text, test path navigation, or exercise the VFS layer during a session.
All files and directories are reset on every boot. RAMFS does not persist data across reboots.
## Filesystem limits
The following constants define the hard limits of the RAMFS implementation (from `include/mvh/fs.h`):
| Constant | Value | Meaning |
| ------------- | ---------- | ----------------------------------------------- |
| `FS_PATH_MAX` | 128 bytes | Maximum full path length |
| `FS_NAME_MAX` | 24 bytes | Maximum file or directory name length |
| `FS_DATA_MAX` | 256 bytes | Maximum data size per file |
| `FS_LIST_MAX` | 64 entries | Maximum entries returned by a directory listing |
***
## ls
List the contents of a directory.
**Syntax**
```sh theme={null}
ls [path]
```
If you omit `path`, the current working directory is listed. Directories are shown with a `[DIR]` prefix in blue; files are shown with `[FILE]` and their size in bytes.
**Example**
```text theme={null}
mvh> ls /
[DIR] home
[DIR] etc
[FILE] notes.txt 42 bytes
```
***
## dir
Alias for `ls`. Accepts the same optional path argument and produces identical output.
**Syntax**
```sh theme={null}
dir [path]
```
**Example**
```text theme={null}
mvh> dir /home
[DIR] user
```
***
## cd
Change the current working directory. Both relative and absolute paths are supported. Running `cd` without an argument changes to `/home`.
**Syntax**
```sh theme={null}
cd
```
**Examples**
```sh theme={null}
cd /home
cd ..
cd logs
```
If the directory does not exist, the shell prints `cd: directory not found`.
***
## pwd
Print the current working directory as an absolute path.
**Syntax**
```sh theme={null}
pwd
```
**Example**
```text theme={null}
mvh> pwd
/home/user
```
***
## mkdir
Create a new directory at the given path. Parent directories must already exist.
**Syntax**
```sh theme={null}
mkdir
```
**Example**
```sh theme={null}
mkdir /home/user
mkdir logs
```
If the path is invalid or a parent directory is missing, the shell prints `mkdir: cannot create directory`.
***
## touch
Create a new empty file. If the file already exists, the command succeeds without modifying its contents.
**Syntax**
```sh theme={null}
touch
```
**Example**
```sh theme={null}
touch notes.txt
touch /home/user/readme.txt
```
***
## write
Write text to a file, replacing any existing content. If the file does not already exist, it is created automatically. The entire argument after the filename is treated as the text to write.
**Syntax**
```sh theme={null}
write
```
**Example**
```text theme={null}
mvh> write notes.txt Hello from MVH Kernel
mvh> cat notes.txt
Hello from MVH Kernel
```
If the text exceeds the 256-byte file limit, the shell prints `write: file is full`.
***
## append
Append text to an existing file without removing previous content. If the file does not exist, it is created first. The total file size must remain within `FS_DATA_MAX` (256 bytes).
**Syntax**
```sh theme={null}
append
```
**Example**
```text theme={null}
mvh> write log.txt First line
mvh> append log.txt Second line
mvh> cat log.txt
First line
Second line
```
***
## cat
Print the full contents of a file to the shell.
**Syntax**
```sh theme={null}
cat
```
**Example**
```text theme={null}
mvh> cat /etc/version
MVH Kernel 1.1.2
```
If the file does not exist, the shell prints `cat: file not found`.
***
## type
Alias for `cat`. Accepts the same path argument and produces identical output.
**Syntax**
```sh theme={null}
type
```
**Example**
```sh theme={null}
type notes.txt
```
***
## open
Open a file and print its contents. Behaves identically to `cat`.
**Syntax**
```sh theme={null}
open
```
**Example**
```sh theme={null}
open notes.txt
```
***
## rm
Remove a file from the filesystem. The path must point to an existing file, not a directory.
**Syntax**
```sh theme={null}
rm
```
**Example**
```sh theme={null}
rm notes.txt
```
If the path is not found, the shell prints `rm: path not found`. If you attempt to remove a non-empty directory, the shell prints `rm: directory is not empty`.
***
## rmdir
Remove a directory. The directory must be empty before removal. `rmdir` is an alias that calls the same underlying removal function as `rm`.
**Syntax**
```sh theme={null}
rmdir
```
**Example**
```sh theme={null}
rmdir /home/user/logs
```
If the directory is not empty, the shell prints `rmdir: directory is not empty`.
***
## mount
List all currently mounted filesystems. In the current release, RAMFS is the only filesystem and is always mounted at `/`.
**Syntax**
```sh theme={null}
mount
```
**Example**
```text theme={null}
mvh> mount
root on / type ramfs (read-write, volatile)
```
***
## df
Display filesystem usage information. In the current release this shows the RAMFS root entry only.
**Syntax**
```sh theme={null}
df
```
**Example**
```text theme={null}
mvh> df
Filesystem Type Mounted on
root ramfs /
```