gists/projects/go-tools/go/goipgrep/README.md

ipgrep

Extract IP addresses (and MAC addresses) from text, with optional reachability checks, reverse DNS, and ipinfo.io lookups.

Build

./scripts/build.sh
./dist/ipgrep --help

Install (local)

./scripts/build.sh
sudo install -m 0755 ./dist/ipgrep /usr/local/bin/ipgrep

Usage

# Extract IPv4 addresses from stdin
cat file.txt | ipgrep

# Extract and uniq/sort
ipgrep -u -s file.txt

# Extract MAC addresses
ipgrep -m file.txt

# Reachability filter (auto chooses ICMP if permitted, otherwise TCP probe)
ipgrep -p file.txt

# Reverse DNS (IP only)
ipgrep -r file.txt

# Lookup ipinfo.io and output CSV (default header included)
ipgrep -l --format=csv file.txt

Notes

• -p/--pingable:
  • --ping-mode=auto (default) uses ICMP echo when raw sockets are available, otherwise falls back to a TCP connect probe.
  • ICMP echo typically requires root or cap_net_raw on Linux:
    • sudo setcap cap_net_raw+ep /path/to/ipgrep
• -l/--lookup cache:
  • defaults to the OS cache dir (override with --cache-path)
  • control size and freshness with --cache-max-entries and --cache-ttl
• MAC -r/--resolve and MAC -p/--pingable are best-effort and rely on the local neighbor/ARP table:
  • Linux: /proc/net/arp
  • Other OSes: currently unsupported without external tooling