oh-wind / mblocs

The status monitoring bar for dwm supports signal triggering.

mblocks

This is a fork of mblocks, which adds some useful functions, such as allowing Interval to be triggered by a signal, and allowing to obtain a semaphore. This is useful for dwm to implement status bar clicks.

This program is a multi-threaded memory-safe status monitor written in Rust. It updates the status only when there is a change.

Installation

First, clone this repository.

git clone https://github.com/oh-wind/mblocs.git

Then, configure the status blocks by editing src/config.rs.

Next, build a release binary.

cargo build --release

If the build succeeds, the binary can be found in target/release/mblocks.

Finally, move the executable to one directory of your PATH directories, and add mblocks & to your ~/.xinitrc.

Configuration

The status monitor can be configured directly in the source src/config.rs. Examples of src/config.rs can be found here and here.

Status blocks are defined in the BLOCKS vector. Each block has a kind, executes a command, and has a prefix and a suffix for formatting.

There are 3 kinds of blocks:

• Once: blocks labeled with this kind are executed once at the start of the program.
• Interval(N): blocks of this type are executed every N seconds. If the signal field is not None, it will fire immediately when this signal is received.
• Signal{ S: signal }: these blocks are executed when the signal S is sent to the mblocks process. To send a signal, you can use kill -$((34 + S)) $(pidof mblocks) where S is the argument given to Signal, and it should not exceed 15 (1 <= S <= 15). This means you can define at most 15 Signal blocks, which is large enough.

The command attribute corresponds to the command to be executed and can be one of the following:

• Shell(COMMAND): this executes the shell command given as arguments (e.g. Shell(&["date", "+%a, %b %d %Y"])). Note the & preceding the array of arguments!
• Function(F): this executes the Rust function F given as argument. These latter can be placed in the directory src/blocks/. Check out the example functions.

The configuration file also defines the SEPARATOR between blocks, which could be any string. The generated status starts with the value of PREFIX and ends with the value of SUFFIX.

Misc.

• If an empty string "" is returned by a block execution, then the corresponding block will not be displayed.
• If the exit status of a Shell command is non-zero, then failed will be shown in the status (in the corresponding block).
• If a Function command returns None, then failed will be shown in the status (in the corresponding block).
• mblocks is memory-safe; it is validated with valgrind. The memory leaks shown by valgrind are false positives related to the signal-hook crate.

License

MIT.