winsorllc Regex Tester
Test regular expressions with syntax validation, match testing, group extraction, and replacement.
Features
- Validate: Check regex syntax validity
- Test: Match patterns against text
- Groups: Extract capture groups
- Replace: Find and replace with regex
- Explain: Get human-readable pattern explanation
- Flags: Support for common regex flags (global, case-insensitive, multiline, dotall)
Usage
# Test pattern matching
./scripts/regex.js --pattern "hello.*world" --text "hello there world"
# Extract groups
./scripts/regex.js --pattern "(\d{3})-(\d{3})-(\d{4})" --text "555-123-4567" --groups
# Replace text
./scripts/regex.js --pattern "\b(\w+)\b" --text "hello world" --replace "[$1]" --global
# Validate regex syntax (no text needed)
./scripts/regex.js --pattern "[a-z+" --validate
# Explain pattern
./scripts/regex.js --pattern "^(\d+)\.(\d+)\.(\d+)$" --explain
# With flags
./scripts/regex.js --pattern "HELLO" --text "hello" --flags "i" # case-insensitive
Flags
| Flag | Description |
|---|---|
g |
Global (find all matches) |
i |
Case-insensitive |
m |
Multiline (^ and $ match start/end of lines) |
s |
Dotall (dot matches newlines) |
Examples
| Task | Command |
|---|---|
| Email validation | ./scripts/regex.js --pattern "^[\w.-]+@[\w.-]+\.\w+$" --text "test@example.com" |
| Phone extraction | ./scripts/regex.js --pattern "\d{3}-\d{3}-\d{4}" --text "Call 555-123-4567" --global |
| URL matching | ./scripts/regex.js --pattern "https?://[^\s]+" --text "Visit https://example.com" |
| Date parsing | ./scripts/regex.js --pattern "(\d{4})-(\d{2})-(\d{2})" --text "2024-03-15" --groups |
| Code search | ./scripts/regex.js --pattern "function\s+(\w+)" --text "function hello() {}" --flags "g" |
Output Format
Valid match:
{
"valid": true,
"matches": 2,
"results": [
{ "match": "hello world", "index": 0, "groups": [] },
{ "match": "hello universe", "index": 12, "groups": [] }
]
}
No match:
{
"valid": true,
"matches": 0,
"message": "No matches found"
}
Invalid pattern:
{
"valid": false,
"error": "Unterminated character class",
"position": 5
}
Pattern Reference
.- Any character (except newline)\d- Digit (0-9)\w- Word character (letters, digits, underscore)\s- Whitespace[]- Character class[^]- Negated character class*- Zero or more+- One or more?- Zero or one^- Start of string$- End of string()- Capture group