swk — Developer's Swiss Army Knife

A single-binary, zero-dependency CLI toolkit for everyday developer tasks.

Install

Quick install (macOS/Linux)

curl -fsSL https://raw.githubusercontent.com/agejevasv/swk/main/install.sh | sh

Or specify a directory:

SWK_INSTALL_DIR=~/.local/bin curl -fsSL https://raw.githubusercontent.com/agejevasv/swk/main/install.sh | sh

Windows: Download the binary from GitHub Releases and add it to your PATH. On WSL, the install script above works as-is.

From source

git clone https://github.com/agejevasv/swk.git
cd swk
make build

Shell completion

swk completion bash > /etc/bash_completion.d/swk
swk completion zsh > "${fpath[1]}/_swk"
swk completion fish > ~/.config/fish/completions/swk.fish

Source your shell or reopen.

Usage

swk <category> <command> [file|input] [flags]

Commands read from stdin when no argument is given, write to stdout, and send errors to stderr (serve, listen, and diff are exceptions). Document-oriented commands (json, xml, markdown, hash, etc.) accept a file path as the argument — if the file exists, its contents are read automatically. Use - to explicitly read stdin.

cat data.json | swk format json
swk format json data.json
swk format json - < data.json

Commands

Category	Description
convert	Data format converters
format	Prettify, minify, and render data
encode	Encoders and decoders
escape	Escape and unescape strings
generate	Data generators
inspect	Inspect and analyze data
query	Query and search data
diff	Compare files
serve	Local static file server
listen	Log incoming HTTP requests

---

Convert (swk convert, swk c)

Command	Description
convert base	Convert between number bases (bin, oct, dec, hex)
convert bytes	Convert between byte sizes and human-readable formats
convert case	Convert between case conventions
convert chmod	Convert between numeric and symbolic file permissions
convert color	Convert between color formats
convert csv2json	Convert CSV to JSON
convert date	Convert between date/time formats
convert duration	Convert between seconds and human-readable durations
convert image / img	Convert image formats, resize
convert json2csv	Convert JSON array to CSV
convert json2yaml	Convert JSON to YAML
convert markdown / md	Render markdown to HTML or plain text
convert yaml2json	Convert YAML to JSON

# Number base conversion
swk convert base 255 --from dec --to hex

# Byte sizes (default: 1024-based with IEC labels)
swk convert bytes 1073741824           # 1 GiB
swk convert bytes '1.5GiB'            # 1610612736
swk convert bytes -d 1000000000        # 1 GB (decimal, 1000-based)
swk convert bytes '1.5GB'             # 1500000000

# Case conversion
echo 'helloWorld' | swk convert case --to snake    # hello_world
echo 'hello world' | swk convert case --to camel   # helloWorld

# File permissions
swk convert chmod 755                  # shows rwxr-xr-x + breakdown
swk convert chmod rwxr-xr-x           # shows 755 + breakdown
swk convert chmod 4755                 # setuid support

# Color format conversion
swk convert color '#FF5733'
swk convert color '255,87,51' --from rgb --to hex

# Date/time conversion
swk convert date 1700000000 --from unix --to iso
swk convert date 1700000000 --from unix --to human --tz UTC
swk convert date now --to unix
swk convert date 1700000000 --from unix --to '%Y-%m-%d' --tz UTC   # 2023-11-14
swk convert date '2023-11-14' --from '%Y-%m-%d' --to unix

# Duration conversion
swk convert duration 86400             # 1d
swk convert duration '2d 5h 30m'      # 192600
swk convert duration 31536000          # 1y
swk convert duration '1y 6mo'         # 47088000

# Image conversion (accepts file path)
swk convert image photo.png --to jpeg -o photo.jpg
swk convert image large.png --to png --resize 200x200 -o thumb.png

# JSON to YAML
echo '{"name":"swk"}' | swk convert json2yaml
swk convert json2yaml data.json

# YAML to JSON
echo 'name: swk' | swk convert yaml2json
swk convert yaml2json config.yaml

# JSON to CSV
echo '[{"name":"alice","age":30}]' | swk convert json2csv

# CSV to JSON
printf 'name,age\nalice,30\n' | swk convert csv2json

# Render markdown (accepts file path)
swk convert markdown README.md --html > preview.html
swk convert markdown README.md --html --syntax-highlight > highlighted.html

Format (swk format, swk fmt, swk f)

Command	Description
format json	Prettify or minify JSON
format xml	Prettify or minify XML
format json2table	Format JSON array as a table
format csv2table	Format CSV as a table

# JSON prettify/minify (accepts file path)
swk format json data.json
swk format json config.json --minify
swk format json data.json --indent 4

# XML format (accepts file path)
swk format xml messy.xml
swk format xml document.xml --minify

# JSON array as table
echo '[{"name":"alice","age":30},{"name":"bob","age":25}]' | swk format json2table
echo '[{"name":"alice"}]' | swk format json2table --style simple

# CSV as table
printf 'name,age\nalice,30\n' | swk format csv2table

# Extract nested array, then render as table
echo '{"meta":"v1","users":[{"name":"alice"},{"name":"bob"}]}' \
  | swk query json '$.users' \
  | swk format json2table

Encode (swk encode, swk enc)

Command	Description
encode base64 / b64	Base64 encode/decode
encode hash / sum	Generate hashes (MD5, SHA1, SHA256, SHA512)
encode html	HTML entity encode/decode (alias of escape html)
encode jwt	Create, decode, or verify JWT tokens
encode qr	Generate QR codes
encode url	URL percent-encode/decode (alias of escape url)

# Base64
echo 'hello world' | swk encode base64
echo 'aGVsbG8gd29ybGQ=' | swk encode base64 -d
echo 'data' | swk encode base64 --url-safe

# Hash (accepts file path)
swk encode hash README.md
swk encode hash README.md --algo md5
echo -n 'hello' | swk encode hash --verify 2cf24dba5fb0a30e26e83b2ac5b9e29e1b161e5c1fa7425e73043362938b9824

# JWT — create with HMAC
swk encode jwt --secret mykey '{"sub":"user1","role":"admin"}'

# JWT — create with RSA/EC/Ed25519
swk encode jwt --algo RS256 --key private.pem '{"sub":"user1"}'
swk encode jwt --algo ES256 --key ec-private.pem '{"sub":"user1"}'

# JWT — decode (no verification, works with any algorithm)
swk encode jwt -d 'eyJhbGciOiJIUzI1NiIs...'

# JWT — verify with HMAC secret
swk encode jwt -d --secret mykey 'eyJhbGciOiJIUzI1NiIs...'

# JWT — verify with public key (RSA/EC/Ed25519)
swk encode jwt -d --key public.pem 'eyJhbGciOiJSUzI1NiIs...'

# QR code
swk encode qr 'https://github.com/agejevasv/swk'
swk encode qr --output png 'https://example.com' > qr.png

Escape (swk escape, swk esc)

Command	Description
escape html	HTML entity escape/unescape
escape json	JSON string escape/unescape
escape shell / sh	Shell escape/unescape
escape url	URL percent-encode/decode
escape xml	XML escape/unescape

# HTML
echo '<script>alert("xss")</script>' | swk escape html
echo '&lt;div&gt;' | swk escape html -u

# JSON
echo 'line1\nline2' | swk escape json
echo '\"hello\"' | swk escape json -u

# Shell
echo "it's a test" | swk escape shell

# URL
echo 'hello world & friends' | swk escape url
echo 'hello%20world' | swk escape url -u

# XML
echo '<tag attr="val">' | swk escape xml

Generate (swk generate, swk g)

Command	Description
generate cert	Generate self-signed TLS certificates
generate cron	Generate cron expressions from flags
generate image	Generate placeholder images
generate password / pw	Generate random passwords
generate text	Generate lorem ipsum text
generate uuid	Generate UUIDs (v1, v4, v5, v7)

# Self-signed TLS certificate
swk generate cert
swk generate cert --cn myapp.local --days 30
swk generate cert --dns localhost --dns myapp.local --ip 127.0.0.1
swk generate cert --key-type rsa -o ./certs/server

# Cron expressions
swk generate cron --every 5m                     # */5 * * * *
swk generate cron --daily --at 9:00              # 0 9 * * *
swk generate cron --weekdays --at 9:00           # 0 9 * * 1-5
swk generate cron --weekly --day MON --at 9:00   # 0 9 * * 1
swk generate cron --monthly --day 15             # 0 0 15 * *
swk generate cron --yearly --month JUN --day 1   # 0 0 1 6 *

# Generate and verify
swk generate cron --daily --at 9:00 | swk inspect cron

# Placeholder image
swk generate image -o placeholder.png
swk generate image --style circles --width 1920 --height 1080 -o wallpaper.png

# Passwords
swk generate password
swk generate password --length 32 --no-symbols
swk generate password --count 10

# Lorem ipsum
swk generate text --paragraphs 3
swk generate text --words 50

# UUIDs
swk generate uuid
swk generate uuid --count 5
swk generate uuid --version 7

Inspect (swk inspect, swk i)

Command	Description
inspect cert	Inspect X.509 PEM certificates
inspect cron	Explain cron expressions
inspect dns	DNS lookups (A, AAAA, MX, NS, TXT, CNAME)
inspect domain	Domain registration info via RDAP
inspect ip	Show your public IP address
inspect jwt	Inspect JWT token claims and expiry
inspect net	List processes listening on network ports (Linux/macOS)
inspect subnet	Calculate subnet information from CIDR
inspect text / txt	Character, word, line, byte counts
inspect url	Parse URL into components

# Certificate (accepts file path)
swk inspect cert cert.pem
swk inspect cert cert.pem --check-expiry

# Cron
swk inspect cron '*/5 * * * *'
swk inspect cron --explain '0 9 * * 1-5'
swk inspect cron --next 3 '0 9 * * MON'

# DNS lookups
swk inspect dns example.com
swk inspect dns example.com --type MX
swk inspect dns 8.8.8.8                # reverse lookup
swk inspect dns --json example.com

# Domain registration info
swk inspect domain example.com
swk inspect domain --json example.com

# Public IP
swk inspect ip

# JWT token inspection
swk inspect jwt 'eyJhbGciOiJIUzI1NiIs...'
echo 'eyJhbGciOiJIUzI1NiIs...' | swk inspect jwt
swk inspect jwt --check-expiry 'eyJhbGciOiJIUzI1NiIs...'
swk inspect jwt --json 'eyJhbGciOiJIUzI1NiIs...'

# Network ports (Linux/macOS)
swk inspect net
swk inspect net --all                   # include established connections
swk inspect net --tcp --port 8080       # filter by protocol and port
swk inspect net --json

# Subnet calculator
swk inspect subnet 192.168.1.0/24
swk inspect subnet 10.0.0.0/16

# Text stats (accepts file path)
swk inspect text essay.txt
echo 'hello world' | swk inspect text --json

# URL parsing
swk inspect url 'https://example.com:8080/api/v1/users?page=1&limit=10#section'

Query (swk query, swk q)

Command	Description
query html	Query HTML with CSS selectors
query json	Query JSON with JSONPath
query regex / re	Match/replace with regular expressions

# HTML (CSS selectors — accepts file path)
curl -s http://example.com | swk query html 'a' --attr href
swk query html 'div.content p' page.html

# JSON (JSONPath — accepts file path)
swk query json '$.users[*].name' data.json

# Regex (pattern is first argument — accepts file path)
echo '2024-01-15 hello 2024-02-20' | swk query regex -o -g '\d{4}-\d{2}-\d{2}'
echo 'John:30' | swk query regex --groups '(\w+):(\d+)'
echo 'foo bar baz' | swk query regex -r 'qux' 'bar'

Diff (swk diff, swk d)

Command	Description
diff text / txt	Unified text diff
diff json	Semantic JSON diff (normalizes key order)

# Text diff
swk diff text old.txt new.txt

# JSON diff (ignores key order)
swk diff json old.json new.json
swk diff json <(curl -s api/v1) <(curl -s api/v2)
curl -s api/v1 | swk diff json - saved.json

Serve (swk serve)

Command	Description
serve	Start a local static file server

# Serve current directory on port 8080
swk serve

# Serve a specific directory on a custom port
swk serve ./dist --port 3000

# Enable CORS headers for local API development
swk serve --cors

# Disable directory listing
swk serve --no-index

# Bind to localhost only, random port
swk serve --host 127.0.0.1 --port 0

# HTTPS with self-signed cert
swk generate cert
swk serve --tls

Listen (swk listen)

Command	Description
listen	Log incoming HTTP requests (webhook receiver)

# Log all incoming requests on port 8080
swk listen

# Custom port and response
swk listen --port 9000 --status 201 --body '{"ok":true}'

# Don't log request bodies
swk listen --no-body

Piping

Commands read stdin and write stdout, making them composable:

# JSON → format → base64
echo '{"a":1}' | swk format json | swk encode base64

# Generate password → tee to stderr → hash
swk generate password | tee /dev/stderr | swk encode hash

# YAML → JSON → minify → clipboard (macOS)
cat config.yaml | swk convert yaml2json | swk format json -m | pbcopy

# Fetch API → format as table
curl -s https://api.example.com/users | swk format json2table

# Extract nested array → table
echo '{"status":"ok","items":[{"id":1,"name":"foo"},{"id":2,"name":"bar"}]}' \
  | swk query json '$.items' \
  | swk format json2table

# Duration roundtrip
swk convert duration '2d 5h' --to seconds | swk convert duration --to human

# Generate cron → verify
swk generate cron --daily --at 9:00 | swk inspect cron

# Scrape links from a webpage
curl -s http://example.com | swk query html 'a' --attr href

Testing

make test          # run all tests
make test-verbose  # run with verbose output
make lint          # run go vet + staticcheck

License

MIT