Install
Install
Three ways in. If you only want to look at an HL7® v2 message and get on with your day, start with the command line — it needs no Rust knowledge at all.
The command line
Two binaries. Each is a single self-contained executable with nothing to install alongside it — no JVM, no interpreter, no service, no configuration file.
cargo install er7 # installs `er7`
cargo install er7-redact # installs `er7-redact`cargo install puts them in ~/.cargo/bin, which Rust’s installer
adds to your PATH.
er7 message.er7 # every value, with the path that names it
er7 --query PID-5.1 message.er7 # read one value
er7 --query OBX-5 message.er7 # every match, one per line
er7 --raw --query OBX-5 message.er7 # text as sent, escapes not decoded
er7 --normalize --terminator lf m.er7 # rewrite as canonical ER7
er7 --message 2 batch.er7 # the second message of a batch
er7-redact message.er7 # redact with the built-in policy
er7-redact --report message.er7 # say what would change, change nothing
er7-redact --show-policy # the built-in policy, as an editable file
er7-redact -p my.policy message.er7 # apply your own policy file
er7-redact -r "NTE-3 clear" m.er7 # or one rule, inlineEvery label in er7’s default outline is itself a valid query, so you can
read a path off the output and paste it straight back in. Reading is from a named file or
standard input, writing to standard output or a named file with -o. The command-line page documents every flag.
Before piping patient data anywhere, note that er7-redact --report prints paths and actions and no values, which is the
form that can safely go into a ticket. Nothing in this family writes a log, opens a socket, or
reads a configuration file: the only bytes that leave are the ones you asked for.
As a library
Take the layer you want, and skip what you do not.
cargo add er7 # parse, query, edit, write. Zero dependencies.
cargo add er7-redact # redaction. One dependency: er7.
cargo add serde-er7 # Serde support. Two: serde and er7.let message = er7::parse(text)?;
assert_eq!(message.query("PID-5.1")?.as_deref(), Some("EVERYWOMAN"));
assert_eq!(message.to_er7(), text); // byte for byteNothing forces you to take all three. er7 depends on nothing at all — that is the
entire tree, which matters where dependency trees get audited. serde-er7 is a separate crate rather than a feature flag for exactly that reason:
adding Serde to er7 would cost every user of er7 a dependency they
may not want.
There are no feature flags on any of the three. Nothing is optional because nothing optional exists.
From source
git clone https://github.com/er7-rust/er7-rust.git
cd er7-rust
cargo build --workspace
cargo test --workspaceOne Cargo.lock at the workspace root covers every member. Use -p <crate> to scope a command to one of them, and run the four checks that
define “done” for any change:
cargo test --workspace
cargo clippy --workspace --all-targets -- -D warnings
cargo fmt --check
cargo rustdoc -p er7 --lib -- -W missing-docsRequirements
| Rust | Current stable minus three releases. Today that is 1.95. |
|---|---|
| Edition | 2024, which needs 1.85 — no longer the binding constraint |
| Platform | Anything Rust targets. No platform-specific code, no C dependency, no build script. |
| Network | None, at build time or run time |
The Rust floor is a rolling window. It is that wide because healthcare toolchains are approved
on a cycle measured in quarters, so a library demanding the compiler released this month is a
library that cannot be adopted. Check a build against the floor with cargo +1.95 check --workspace --all-targets. If you do not have Rust: rustup.rs.
Verifying the install
er7 --version
printf 'MSH|^~\\&|LAB|ACME|EHR|CLINIC|20260814080000||ADT^A08|MSG1|P|2.5\r' | er7The second prints an outline whose first lines are MSH-1, MSH-2, and MSH-3. If it does, you are done. The current release is er7 0.1.3.
Uninstalling
cargo uninstall er7
cargo uninstall er7-redactNothing is left behind: no configuration directory was created, no cache was written, no service was registered.