Pattern Syntax Guide

The pattern system allows you to generate multiple username or email variations from a single compact pattern definition. This is useful for searching variations of a username/email similar to your desire.

Quick Start

Use patterns directly with the -u (username) or -e (email) flags:

# Scan "johna", "johnb", "johnc"
user-scanner -u "john[a-c]"

# Scan up to 50 permutations instead of default 100
user-scanner -u "john[0-9]{0-2}" -s 50

# Scan multiple variations with case differences
user-scanner -u "[jJ]ohn[0-9]{1-2}"

# With emails
user-scanner -e "user[a-z]{0-1}@example.com"

The -s flag (short for --stop) limits how many permutations are scanned. By default, only the first 100 are checked.

Pattern Syntax

Character Sets: [chars]

Define a character set using square brackets. Characters between the brackets will each become a separate variation.

Examples:

john[abc]         → "johna", "johnb", "johnc"
user[0-9]         → "user0", "user1", ..., "user9"
test[a-zA-Z]      → "testa", "testb", ..., "testZ"
site[_.-]         → "site_", "site.", "site-"

Character Range Syntax:

• [a-z] - lowercase letters a through z
• [A-Z] - uppercase letters A through Z
• [0-9] - digits 0 through 9
• [a-zA-Z0-9] - combined ranges
• [abc] - literal characters a, b, c

Note: "-" must be placed at the beginning or at the end of the range to be interpreted as a character.

Length Control: [chars]{len}

Specify the length of expansions from a character set.

Examples:

john[a-z]{0-2}    → "john", "johna", "johnb", ..., "johnz", "johnaa", ..., "johnzz"
code[0-9]{2}      → "code00", "code01", ..., "code99"
user[a-c]{1;3}    → "usera", "userb", "userc", "useraa", ..., "userccc"
text[0-1]{1-3}    → "text0", "text1", "text00", "text01", "text10", "text11", ..., "text111"

Length Syntax:

• {n} - exactly n characters
• {n-m} - between n and m characters (inclusive)
• {n;m} - exactly n or m characters
• {0-n} - zero to n characters

Common Use Cases

Username Variations with Numbers

user-scanner -u "john[0-9]{0-3}"

Scans up to 100 variations: john, john0–john9, john00–john99, john000–john999

Multiple Name Parts with Case Variations

user-scanner -u "[jJ]ohn[0-9]{0-2}"

Scans variations like: john, John, john0–john99, John0–John99

Underscore and Dot Variations

user-scanner -u "user[_.]name"

Scans: user_name, user.name

Email with Variations

user-scanner -e "user[a-z]{0-1}@example.com"

Scans email addresses: user@example.com, usera@example.com–userz@example.com

Limiting Scan Results

Use the -s or --stop flag to limit how many permutations are checked:

# Check only 10 permutations instead of default 100
user-scanner -u "john[0-9]{0-3}" -s 10

The tool will show you how many permutations are available:

[+] Scanning 10 of 1111 permutations

Viewing Available Permutations

The tool automatically shows how many variations were found and scans up to the limit you set.

Performance Tips

1. Start with limits - Always use -s to limit how many permutations you scan:

   user-scanner -u "pattern[0-9]{0-3}" -s 25
   

2. Check pattern complexity - A pattern like [a-z]{5} would generate 11,881,376 combinations. Start small and increase gradually.

3. Use moderate ranges - Keep character sets and length ranges reasonable:

   • Good: [a-c]{0-2} (~15 variations)
   • Risky: [a-z]{0-3} (~18,278 variations)

4. Combine with other filters - Use -c (category) or -m (module) to narrow the scope:

   user-scanner -u "user[a-z]{0-1}" -c social -s 50
   

5. Add delays between requests - Use the --delay flag to avoid rate limiting:

   user-scanner -u "test[0-9]{1-2}" --delay 1.0
   

CLI Examples

Simple usernames with numbers

user-scanner -u "johnny[0-9]{0-2}"

Case variations

user-scanner -u "[jJ]ohn[0-9]{1-2}"

Multiple separators

user-scanner -u "john[._-]doe"

Complex pattern with limited scans

user-scanner -u "user[a-z]{0-1}[0-9]{0-2}" -s 50

Email pattern variations

user-scanner -e "[jJ]ohn[_.]doe@example.com"

Combining with other flags

# Scan a pattern with verbose output and delay between requests
user-scanner -u "admin[0-9]{1-2}" -v --delay 0.5 -s 25

# Scan with a specific category
user-scanner -u "user[a-c]" -c social -s 50

Pattern Limitations

• Do not nest brackets: [[a-z]] is invalid
• Ranges must go from lower to higher ASCII values (e.g., [z-a] is invalid)
• The pattern engine is designed for generating variations, not complex regex-like patterns