Expand description
mailcap
mailcap is a parsing library for mailcap files.
Mailcap files are a format documented in RFC
1524, “A User Agent Configuration
Mechanism For Multimedia Mail Format Information.” They allow the handling of
MIME types by software aware of those types. For example, a mailcap line of
text/html; qutebrowser '%s'; test=test -n "$DISPLAY" would instruct the
software to open any HTML file with qutebrowser if you are running a graphical
session, with the file replacing the '%s'.
mailcap is a parsing library that looks at either a present $MAILCAPS env
variable or cycles through the four paths where a mailcap file would be found in
ascending order of importance: /usr/local/etc/mailcap, /usr/etc/mailcap,
/etc/mailcap, and $HOME/.mailcap. It builds the mailcap from all available
files, with duplicate entries being squashed with newer lines, allowing
$HOME/.mailcap to be the final decider.
The entries that make up the mailcap include only those that are relevant i.e.
those that have passed the test field (if present). With the above text/html
example, that test would fail if run through SSH, and unless another existing
text/html entry (or text/*) exists that doesn’t require a display server, no
entry would exist for that mime type.
Usage
use mailcap::{Mailcap, MailcapError};
fn main() -> Result<(), MailcapError> {
let cap = Mailcap::new()?;
if let Some(i) = cap.get("text/html") {
let command = i.viewer("/var/www/index.html");
assert_eq!(command, "qutebrowser '/var/www/index.html'");
}
Ok(())
}Wildcard fallbacks are also supported.
use mailcap::{Mailcap, MailcapError};
fn main() -> Result<(), MailcapError> {
let cap = Mailcap::new()?;
if let Some(i) = cap.get("video/avi") {
// if no video/avi MIME entry available
let mime_type = i.mime();
assert_eq!(mime_type, "video/*");
}
Ok(())
}Structs
Parsed mailcap line. Each mailcap entry consists of a number of fields, separated by semi-colons. The first two fields are required, and must occur in the specified order. The remaining fields are optional, and may appear in any order.
Meta representation of all available mailcap files and their combined lines.
Enums
The error type for mailcap.