# Send Regex Patterns to your agent Hand the extracted package to your coding agent with a concrete install brief instead of figuring it out manually. ## Fast path - Download the package from Yavira. - Extract it into a folder your agent can access. - Paste one of the prompts below and point your agent at the extracted folder. ## Suggested prompts ### New install ```text I downloaded a skill package from Yavira. Read SKILL.md from the extracted folder and install it by following the included instructions. Tell me what you changed and call out any manual steps you could not complete. ``` ### Upgrade existing ```text I downloaded an updated skill package from Yavira. Read SKILL.md from the extracted folder, compare it with my current installation, and upgrade it while preserving any custom configuration unless the package docs explicitly say otherwise. Summarize what changed and any follow-up checks I should run. ``` ## Machine-readable fields ```json { "schemaVersion": "1.0", "item": { "slug": "regex-patterns", "name": "Regex Patterns", "source": "tencent", "type": "skill", "category": "开发工具", "sourceUrl": "https://clawhub.ai/gitgoodordietrying/regex-patterns", "canonicalUrl": "https://clawhub.ai/gitgoodordietrying/regex-patterns", "targetPlatform": "OpenClaw" }, "install": { "downloadUrl": "/downloads/regex-patterns", "sourceDownloadUrl": "https://wry-manatee-359.convex.site/api/v1/download?slug=regex-patterns", "sourcePlatform": "tencent", "targetPlatform": "OpenClaw", "packageFormat": "ZIP package", "primaryDoc": "SKILL.md", "includedAssets": [ "SKILL.md" ], "downloadMode": "redirect", "sourceHealth": { "source": "tencent", "slug": "regex-patterns", "status": "healthy", "reason": "direct_download_ok", "recommendedAction": "download", "checkedAt": "2026-05-08T01:59:54.481Z", "expiresAt": "2026-05-15T01:59:54.481Z", "httpStatus": 200, "finalUrl": "https://wry-manatee-359.convex.site/api/v1/download?slug=regex-patterns", "contentType": "application/zip", "probeMethod": "head", "details": { "probeUrl": "https://wry-manatee-359.convex.site/api/v1/download?slug=regex-patterns", "contentDisposition": "attachment; filename=\"regex-patterns-1.0.0.zip\"", "redirectLocation": null, "bodySnippet": null, "slug": "regex-patterns" }, "scope": "item", "summary": "Item download looks usable.", "detail": "Yavira can redirect you to the upstream package for this item.", "primaryActionLabel": "Download for OpenClaw", "primaryActionHref": "/downloads/regex-patterns" }, "validation": { "installChecklist": [ "Use the Yavira download entry.", "Review SKILL.md after the package is downloaded.", "Confirm the extracted package contains the expected setup assets." ], "postInstallChecks": [ "Confirm the extracted package includes the expected docs or setup files.", "Validate the skill or prompts are available in your target agent workspace.", "Capture any manual follow-up steps the agent could not complete." ] } }, "links": { "detailUrl": "https://openagent3.xyz/skills/regex-patterns", "downloadUrl": "https://openagent3.xyz/downloads/regex-patterns", "agentUrl": "https://openagent3.xyz/skills/regex-patterns/agent", "manifestUrl": "https://openagent3.xyz/skills/regex-patterns/agent.json", "briefUrl": "https://openagent3.xyz/skills/regex-patterns/agent.md" } } ``` ## Documentation ### Regex Patterns Practical regular expression cookbook. Patterns for validation, parsing, extraction, and refactoring across JavaScript, Python, Go, and command-line tools. ### When to Use Validating user input (email, URL, IP, phone, dates) Parsing log lines or structured text Extracting data from strings (IDs, numbers, tokens) Search-and-replace in code (rename variables, update imports) Filtering lines in files or command output Debugging regexes that don't match as expected ### Metacharacters PatternMatchesExample.Any character (except newline)a.c matches abc, a1c\\dDigit [0-9]\\d{3} matches 123\\wWord char [a-zA-Z0-9_]\\w+ matches hello_123\\sWhitespace [ \\t\\n\\r\\f]\\s+ matches spaces/tabs\\bWord boundary\\bcat\\b matches cat not scatter^Start of line^Error matches line starting with Error$End of line\\.js$ matches line ending with .js\\D, \\W, \\SNegated: non-digit, non-word, non-space ### Quantifiers PatternMeaning*0 or more (greedy)+1 or more (greedy)?0 or 1 (optional){3}Exactly 3{2,5}Between 2 and 5{3,}3 or more*?, +?Lazy (match as few as possible) ### Groups and Alternation PatternMeaning(abc)Capture group(?:abc)Non-capturing group(?Pabc)Named group (Python)(?abc)Named group (JS/Go)a|bAlternation (a or b)[abc]Character class (a, b, or c)[^abc]Negated class (not a, b, or c)[a-z]Range ### Lookahead and Lookbehind PatternMeaning(?=abc)Positive lookahead (followed by abc)(?!abc)Negative lookahead (not followed by abc)(?<=abc)Positive lookbehind (preceded by abc)(?|(?:async\\s+)?function\\s*\\()' src/*.ts # Find class definitions grep -nP 'class\\s+\\w+(?:\\s+extends\\s+\\w+)?' src/*.ts # Find import statements grep -nP '^import\\s+.*\\s+from\\s+' src/*.ts # Find TODO/FIXME/HACK comments grep -rnP '(?:TODO|FIXME|HACK|XXX|WARN)(?:\\([^)]+\\))?:?\\s+' src/ # Find console.log left in code grep -rnP 'console\\.(log|debug|info|warn|error)\\(' src/ --include='*.ts' --include='*.js' ### Data Extraction # Extract all email addresses from a file grep -oP '[a-zA-Z0-9._%+-]+@[a-zA-Z0-9.-]+\\.[a-zA-Z]{2,}' file.txt # Extract all URLs grep -oP 'https?://[^\\s<>"]+' file.html # Extract all quoted strings grep -oP '"[^"\\\\]*(?:\\\\.[^"\\\\]*)*"' file.json # Extract numbers (integer and decimal) grep -oP '-?\\d+\\.?\\d*' data.txt # Extract key-value pairs (key=value) grep -oP '\\b(\\w+)=([^\\s&]+)' query.txt # Extract hashtags grep -oP '#\\w+' posts.txt # Extract hex colors grep -oP '#[0-9a-fA-F]{3,8}\\b' styles.css ### JavaScript // Test if a string matches const emailRegex = /^[a-zA-Z0-9._%+-]+@[a-zA-Z0-9.-]+\\.[a-zA-Z]{2,}$/; emailRegex.test('user@example.com'); // true // Extract with capture groups const match = '2026-02-03T12:30:00Z'.match(/(\\d{4})-(\\d{2})-(\\d{2})/); // match[1] = '2026', match[2] = '02', match[3] = '03' // Named groups const m = 'John Doe, age 30'.match(/(?[A-Za-z ]+), age (?\\d+)/); // m.groups.name = 'John Doe', m.groups.age = '30' // Find all matches (matchAll returns iterator) const text = 'Call 555-1234 or 555-5678'; const matches = [...text.matchAll(/\\d{3}-\\d{4}/g)]; // [{0: '555-1234', index: 5}, {0: '555-5678', index: 18}] // Replace with callback 'hello world'.replace(/\\b\\w/g, c => c.toUpperCase()); // 'Hello World' // Replace with named groups '2026-02-03'.replace(/(?\\d{4})-(?\\d{2})-(?\\d{2})/, '$/$/$'); // '02/03/2026' // Split with regex 'one, two; three'.split(/[,;]\\s*/); // ['one', 'two', 'three'] ### Python import re # Match (anchored to start) m = re.match(r'^(\\w+)@(\\w+)\\.(\\w+)$', 'user@example.com') if m: print(m.group(1)) # 'user' # Search (find first match anywhere) m = re.search(r'\\d{3}-\\d{4}', 'Call 555-1234 today') print(m.group()) # '555-1234' # Find all matches emails = re.findall(r'[\\w.+-]+@[\\w.-]+\\.\\w{2,}', text) # Named groups m = re.match(r'(?P\\w+)\\s+(?P\\d+)', 'Alice 30') print(m.group('name')) # 'Alice' # Substitution result = re.sub(r'\\bfoo\\b', 'bar', 'foo foobar foo') # 'bar foobar bar' # Sub with callback result = re.sub(r'\\b\\w', lambda m: m.group().upper(), 'hello world') # 'Hello World' # Compile for reuse (faster in loops) pattern = re.compile(r'\\d{4}-\\d{2}-\\d{2}') dates = pattern.findall(log_text) # Multiline and DOTALL re.findall(r'^ERROR.*$', text, re.MULTILINE) # ^ and $ match line boundaries re.search(r'start.*end', text, re.DOTALL) # . matches newlines # Verbose mode (readable complex patterns) pattern = re.compile(r''' ^ # Start of string (?P\\d{4}) # Year -(?P\\d{2}) # Month -(?P\\d{2}) # Day $ # End of string ''', re.VERBOSE) ### Go import "regexp" // Compile pattern (panics on invalid regex) re := regexp.MustCompile(\`\\d{4}-\\d{2}-\\d{2}\`) // Match test re.MatchString("2026-02-03") // true // Find first match re.FindString("Date: 2026-02-03 and 2026-03-01") // "2026-02-03" // Find all matches re.FindAllString(text, -1) // []string of all matches // Capture groups re := regexp.MustCompile(\`(\\w+)@(\\w+)\\.(\\w+)\`) match := re.FindStringSubmatch("user@example.com") // match[0] = "user@example.com", match[1] = "user", match[2] = "example" // Named groups re := regexp.MustCompile(\`(?P\\d{4})-(?P\\d{2})-(?P\\d{2})\`) match := re.FindStringSubmatch("2026-02-03") for i, name := range re.SubexpNames() { if name != "" { fmt.Printf("%s: %s\\n", name, match[i]) } } // Replace re.ReplaceAllString("foo123bar", "NUM") // "fooNUMbar" // Replace with function re.ReplaceAllStringFunc(text, strings.ToUpper) // Note: Go uses RE2 syntax — no lookahead/lookbehind ### Command Line (grep/sed) # grep -P uses PCRE (Perl-compatible — full features) # grep -E uses Extended regex (no lookahead/lookbehind) # Find lines matching a pattern grep -P '\\d{3}-\\d{4}' file.txt # Extract only the matching part grep -oP '\\d{3}-\\d{4}' file.txt # Invert match (lines NOT matching) grep -vP 'DEBUG|TRACE' app.log # sed replacement sed 's/oldPattern/newText/g' file.txt # Basic sed -E 's/foo_([a-z]+)/bar_\\1/g' file.txt # Extended with capture group # Perl one-liner (most powerful) perl -pe 's/(?<=price:\\s)\\d+/0/g' file.txt # Lookbehind works in Perl ### Code Refactoring # Rename a variable across files grep -rlP '\\boldName\\b' src/ | xargs sed -i 's/\\boldName\\b/newName/g' # Convert var to const (JavaScript) sed -i -E 's/\\bvar\\b/const/g' src/*.js # Convert single quotes to double quotes sed -i "s/'/\\"/g" src/*.ts # Add trailing commas to object properties sed -i -E 's/^(\\s+\\w+:.+[^,])$/\\1,/' config.json # Update import paths sed -i 's|from '\\''../old-path/|from '\\''../new-path/|g' src/*.ts # Convert snake_case to camelCase (Python → JavaScript naming) perl -pe 's/_([a-z])/uc($1)/ge' file.txt ### Text Cleanup # Remove trailing whitespace sed -i 's/[[:space:]]*$//' file.txt # Remove blank lines sed -i '/^$/d' file.txt # Remove duplicate blank lines (keep at most one) sed -i '/^$/N;/^\\n$/d' file.txt # Trim leading and trailing whitespace from each line sed -i 's/^[[:space:]]*//;s/[[:space:]]*$//' file.txt # Remove HTML tags sed 's/<[^>]*>//g' file.html # Remove ANSI color codes sed 's/\\x1b\\[[0-9;]*m//g' output.txt ### Greedy vs lazy matching Pattern: <.*> Input: bold Greedy matches: bold (entire string between first < and last >) Lazy matches: (stops at first >) Pattern: <.*?> (lazy version) ### Escaping special characters Characters that need escaping in regex: . * + ? ^ $ { } [ ] ( ) | \\ In character classes []: only ] - ^ \\ need escaping # To match a literal dot: \\. # To match a literal *: \\* # To match a literal \\: \\\\ # To match [ or ]: \\[ or \\] ### Newlines and multiline By default . does NOT match newline. By default ^ and $ match start/end of STRING. # To make . match newlines: JavaScript: /pattern/s (dotAll flag) Python: re.DOTALL or re.S Go: (?s) inline flag # To make ^ $ match line boundaries: JavaScript: /pattern/m (multiline flag) Python: re.MULTILINE or re.M Go: (?m) inline flag ### Backtracking and performance # Catastrophic backtracking (avoid these patterns on untrusted input): (a+)+ # Nested quantifiers (a|a)+ # Overlapping alternation (.*a){10} # Ambiguous .* with repetition # Safe alternatives: [a]+ # Instead of (a+)+ a+ # Instead of (a|a)+ [^a]*a # Possessive/atomic instead of .*a ### Tips Start simple and add complexity. \\d+ is almost always enough — you rarely need [0-9]+. Test your regex on real data, not just the happy path. Edge cases (empty strings, special characters, Unicode) break naive patterns. Use non-capturing groups (?:...) when you don't need the captured value. It's slightly faster and cleaner. In JavaScript, always use the g flag for matchAll and global replace. Without it, only the first match is found/replaced. Go's regexp package uses RE2 (no lookahead/lookbehind). If you need those, use a different approach or the regexp2 package. grep -P (PCRE) is the most powerful command-line regex. Use it over grep -E when you need lookahead, \\d, or \\b. For complex patterns, use verbose mode (re.VERBOSE in Python, /x in Perl) with comments explaining each part. Regex is the wrong tool for parsing HTML, XML, or JSON. Use a proper parser. Regex works for extracting simple values from these formats, not for structural parsing. ## Trust - Source: tencent - Verification: Indexed source record - Publisher: gitgoodordietrying - Version: 1.0.0 ## Source health - Status: healthy - Item download looks usable. - Yavira can redirect you to the upstream package for this item. - Health scope: item - Reason: direct_download_ok - Checked at: 2026-05-08T01:59:54.481Z - Expires at: 2026-05-15T01:59:54.481Z - Recommended action: Download for OpenClaw ## Links - [Detail page](https://openagent3.xyz/skills/regex-patterns) - [Send to Agent page](https://openagent3.xyz/skills/regex-patterns/agent) - [JSON manifest](https://openagent3.xyz/skills/regex-patterns/agent.json) - [Markdown brief](https://openagent3.xyz/skills/regex-patterns/agent.md) - [Download page](https://openagent3.xyz/downloads/regex-patterns)