eed is a minimal encrypted line editor written in C. It edits one file at a time, keeps plaintext in memory, and writes authenticated ciphertext to disk.

• Password-based encryption with Argon2id + AES-256-GCM
• Atomic saves
• File locking to prevent concurrent edits
• Basic line editing commands: append, insert, change, delete, print, search, substitute, write, quit
• Encrypted hidden sidecar .<filename>.bak for the latest saved state

eed needs a C compiler and OpenSSL 3.5+.

The Makefile does not auto-detect OpenSSL. You must point it at your OpenSSL installation yourself.

If your OpenSSL install uses the usual prefix layout:

make OPENSSL_PREFIX=/path/to/openssl

If you need to pass the flags explicitly:

make OPENSSL_CFLAGS='-I/path/to/openssl/include' \
     OPENSSL_LDFLAGS='-L/path/to/openssl/lib' \
     OPENSSL_LIBS='-lcrypto'

Some platforms may also need extra compiler defines in CPPFLAGS.

Example on this macOS setup:

make OPENSSL_PREFIX=/Users/ettore/Devel/openssl \
     CPPFLAGS='-D_DARWIN_C_SOURCE'

./eed secret.eed

To require mlockall() for extra hardening:

./eed -m secret.eed

This is intentionally small and strict: one buffer, one file, no undo, no shell escapes, no rich UI. Memory locking is optional and only enabled when you pass -m.