CLI Reference

Complete command-line reference for Nerva.

Synopsis

nerva [flags]

Target Specification

Nerva requires targets in host:port or ip:port format. It assumes ports are already open.

# Single target
nerva -t example.com:22

# Multiple targets
nerva -t example.com:22,example.com:80,example.com:443

# From file
nerva -l targets.txt

# From stdin
cat targets.txt | nerva
naabu -host example.com -silent | nerva

Flags

Flag	Short	Type	Default	Description
--targets	-t	string	—	Target or comma-separated target list
--list	-l	string	—	Input file containing targets (one per line)
--output	-o	string	stdout	Output file path
--json		bool	false	Output in JSON format
--csv		bool	false	Output in CSV format
--fast	-f	bool	false	Fast mode (default ports only)
--udp	-U	bool	false	Run UDP plugins
--sctp	-S	bool	false	Run SCTP plugins (Linux only)
--timeout	-w	int	2000	Timeout in milliseconds
--verbose	-v	bool	false	Verbose output to stderr
--help	-h			Show help

Output Formats

Default (Human-Readable)

$ nerva -t example.com:22
ssh://example.com:22

JSON

$ nerva -t example.com:22 --json
{"host":"example.com","ip":"93.184.216.34","port":22,"protocol":"ssh","transport":"tcp","metadata":{...}}

CSV

$ nerva -t example.com:22 --csv
host,ip,port,protocol,transport,tls
example.com,93.184.216.34,22,ssh,tcp,false

Examples

Basic Usage

# Fingerprint SSH
nerva -t server.example.com:22

# Fingerprint multiple services
nerva -t server.example.com:22,server.example.com:80,server.example.com:443

File Input

# Create targets file
echo "example.com:22" > targets.txt
echo "example.com:80" >> targets.txt
echo "example.com:443" >> targets.txt

# Scan from file
nerva -l targets.txt

# With JSON output to file
nerva -l targets.txt --json -o results.json

Pipeline Integration

# With Naabu
naabu -host example.com -silent | nerva --json

# With Masscan
masscan -p1-65535 10.0.0.0/24 --rate=1000 -oL - | \
  awk '{print $4":"$3}' | nerva --json

# Filter specific protocols
nerva -l targets.txt --json | jq 'select(.protocol=="ssh")'

UDP Scanning

# UDP may require root privileges
sudo nerva -t example.com:53 -U
# dns://example.com:53

SCTP Scanning (Linux Only)

# Diameter over SCTP for telecom
nerva -t mme.telecom.local:3868 -S --json

Fast Mode

# Only check default port for each protocol
nerva -l large-target-list.txt --fast --json

Timeout Adjustment

# Increase timeout for slow services
nerva -t slow-server.example.com:8080 -w 5000  # 5 seconds

See Also

• Protocol List
• Library Usage
• Integration Guide