smbox

A minimalist mbox reader.

About

smbox is for people (like me) who may have remote servers which have cron jobs or other system services reporting via local system mail.

Using Mutt or a similarly fully fledged terminal based client to read system mail feels like overkill but using plain old MAIL(1) is just a bit too old school, and so smbox tries to sit in between.

Current Features

• Can read from $MAIL and display messages using a basic TUI.
• Can delete messages.
• Can highlight sections of the email bodies using regular expressions.

Caveats

• Barely tested though I use it every day.
• It's designed to work with unix OSes and uses some unix specific library calls. I haven't tried it on MacOS and I can't imagine how it would even work on Windows if you did force it to compile.

Config File

The config file is found at ${CONFIG_DIR}/smbox.ron, e.g., ~/.config/smbox.ron. It is RON and can contain the declarations needed for highlighting parts of the email message text.

It has the following format:

(
    highlights: [
        (   // First highlighter.
            enter: <regex>,
            exit: Some(<regex>),
            matches: [
                (match: <regex 1>, colour: <clr 1>),
                (match: <regex 2>, colour: <clr 2>),
                .
                .
                (match: <regex n>, colour: <clr n>),
            ]
        ),
        (   // Second highlighter...
            enter: <regex>,
            matches: [
                (match: <regex 1>, colour: <clr 1>),
                (match: <regex 2>, colour: <clr 2>),
                .
                .
                (match: <regex n>, colour: <clr n>),
            ]
        ),
    ]
)
etc.

• regex is a string which will work with the [regex](https://github.com/rust-lang/regex) crate.
• The enter regular expression value turns that context on.
• The exit regular expression turns it off again, and is optional (but must be Some(..) when present).
• The matches are pairs of regular expressions and 256 colour indices which will be matched against lines of text while that context is 'alive'.
• The regular expressions may contain captures (between parentheses) in which case the first capture will be highlighted rather than the entire match, as is the default.

E.g.,

(
    highlights: [
        (   // Login failures.  Enter this context when we see 'login failures:'.  Exit on a blank line.
            enter: " login failures:$",
            exit: Some("^$"),
            matches: [
                // Highlight reported unknown users in colour 140.
                (match: "unknown user (.*) ", colour: 140),
                // Highlight the words 'invalid protocol' when found, with colour 87.
                (match: "invalid protocol", colour: 87),
            ]
        ),
        (   // Let's encrypt.
            enter: "^Processing.*letsencrypt",
            matches: [
                (match: "^Certificate not yet due for renewal$",     colour: 107),
                (match: "^Renewing an existing certificate for .*$", colour: 222),
                (match: "^Congratulations, all renewals succeeded:", colour: 107),
            ]
        ),
    ]
)