hostab 0.0.2

Your dev tool to manage /etc/hosts like a pro — written in Rust
Documentation

hostab

License: MIT

Your dev tool to manage /etc/hosts like a pro — written in Rust.

A fast, safe hosts file manager distributed as a single static binary.

Why hostab?

  • Atomic writes — write to .tmp, fsync, rename (no partial writes)
  • File locking — flock prevents concurrent modification
  • DNS resolution — forward and reverse lookups via hickory-resolver
  • Filter & search — wildcard / regex filter, auto-detect pattern type
  • Merge — combine hosts files from local or remote sources
  • Multi-format output — table, raw TSV, markdown, JSON

Installation

cargo install hostab

Or download from releases (Linux x86_64/ARM64/ARMv7, macOS x86_64/Apple Silicon, Windows x86_64).

Quick Start

# List (compact by default)
hostab e list

# Filter with auto-detect (*/? → glob, else substring)
hostab e list -f "prod*"
hostab e list -f localhost -i

# IPv4 / IPv6 only
hostab e list --ipv4

# Add
hostab e add 10.0.0.1 app.local api.local
hostab e add 10.0.0.2 db.local --comment "database"

# Remove
hostab e rm app.local
hostab e rm --ip 10.0.0.1

# Enable / disable / toggle (auto-split from shared IP)
hostab e disable api.local
hostab e enable api.local
hostab e toggle api.local
hostab e disable --ip 10.0.0.1

# Move hostname to new IP
hostab e edit api.local --ip 10.0.0.99

# DNS resolution
hostab resolve github.com
hostab resolve 8.8.8.8
hostab resolve -l localhost       # local hosts file only

# Merge from multiple sources
hostab merge -s ./dev-hosts -s https://example.com/hosts

# Validate (table output with LINE/IP/HOST/ISSUE)
hostab verify

Commands

Entry (e)

Command Description
e list [--ipv4|--ipv6] [--expand] [-f FILTER] [-i] List entries, auto-detect filter
e add <ip> <hosts...> [--comment X] Add or merge entry
e rm <hosts...> [--ip X] Remove by hostname or IP
e disable <hosts...> [--ip X] Comment out (split from shared IP)
e enable <hosts...> [--ip X] Uncomment (merge back)
e toggle <host> [--ip X] Flip enabled/disabled
e edit <host> --ip X Move hostname to new IP

Top-level

Command Description
resolve <hosts...> [-l] DNS forward/reverse lookup, -l for local only
merge -s <src...> [-t <target>] Merge from files/URLs
verify [--strict] Validate, table output (LINE/IP/HOST/ISSUE)
cat Print raw hosts file
completion <bash|zsh|fish> Shell completion
version Version + commit + build date

Filter (auto-detect)

hostab e list -f local      # substring match
hostab e list -f "prod*"    # glob (*/? wildcards)
hostab e list -f "db.loca?" # glob single-char
hostab e list -f local -i   # case insensitive

Output Formats

--out table (default, compact):

│ ip            │ host                │ comment  │
├───────────────┼─────────────────────┼──────────┤
│ 127.0.0.1     │ localhost           │          │
│ 10.0.0.1      │ app.local api.local │          │

--out json: [{"ip":"127.0.0.1","host":"localhost","comment":null}]

--out raw: tab-separated; --out markdown: GitHub-flavored table.

Verify output

╭──────┬───────────┬───────────┬───────────╮
│ LINE │ ip        │ host      │ issue     │
├──────┼───────────┼───────────┼───────────┤
│ 1    │ 127.0.0.1 │ localhost │ duplicate │
│ 2    │ ::1       │ localhost │ duplicate │
╰──────┴───────────┴───────────┴───────────╯

Global Options

--hosts-file <PATH>   [env: HOSTS_FILE] [default: /etc/hosts]
-q, --quiet
-o, --out <FORMAT>    table, raw, markdown, json

Safety

  • Atomic writes — .tmp → fsync → rename
  • File locking — flock prevents concurrent access
  • Duplicate detection — warns on re-add, verify finds duplicates
  • Split/merge — disable/enable preserves co-hosted hostnames

License

MIT