Denev CLI

Denev (a portmanteau of Deneb, a star, and “dev” for developer) is a cross-platform command-line toolkit that brings together the kinds of utilities developers reach for every day. Instead of switching between operating-system-specific commands, standalone utilities, online tools, and one-off scripts, Denev provides a single, consistent interface for recurring development tasks.

Whether you need to inspect JSON, generate UUIDs or random values, compute hashes, inspect certificates or JWTs, diagnose HTTP endpoints, or manipulate URLs and timestamps, the commands follow the same conventions across Windows, Linux, and macOS. The executable is named dnv.

A consistent way to solve everyday problems

Denev is built around a simple idea: developer utilities should not interrupt your workflow.

Many everyday tasks are individually simple, but they often require switching tools, remembering different command syntaxes, or leaving the terminal entirely. One task uses a tool, another relies on a browser-based JWT decoder, another requires a platform-specific utility, and yet another depends on a small script you wrote months ago.

Denev focuses on the common operations developers perform repeatedly and gives them a unified interface. Once you become familiar with one command, the others should feel immediately recognizable.

The goal is to provide one coherent command-line experience.

Design philosophy

Every command in Denev follows the same design principles.

Consistency first. Most commands share the same structure, option naming, exit codes, and output conventions whenever possible.

Human-friendly by default. Output is designed to be easy to read by humans.

Automation-ready. When you need to script or integrate Denev into CI pipelines, commands expose machine-friendly output through options such as --quiet.

Good defaults. The most common operation should require the fewest arguments while still remaining explicit when needed.

Guardrails instead of restrictions. Potentially unsafe operations are explained with warnings rather than unnecessarily prohibited, leaving the final decision to the user.

These principles apply consistently throughout the CLI so that learning one module makes the next one feel familiar.

About this documentation

This documentation follows the same philosophy as the CLI itself. Every command is documented using the same structure:

a short description explaining its purpose; the command syntax; available arguments and options; practical examples; notes, tips, and warnings where appropriate.

Shared concepts, such as standard input, quiet output, file handling, and exit codes, are explained once before the module reference to avoid repeating the same information throughout the documentation.

Installation

Denev is designed to run on Windows 10 and 11, Linux (x86_64 and arm64), and macOS (both Intel and Apple Silicon). You can download Denev directly from the download page, or, even easier, use one of the following methods:

Linux, macOS, and Windows (Git Bash, WSL)

curl -fsSL https://denev.pages.dev/install.sh | bash

Windows x86_64 (PowerShell 5.1+)

irm https://denev.pages.dev/install.ps1 | iex

Once dnv is installed, verify that it is on your PATH:

dnv --version
dnv --help

Tip: If you didn’t use one of the install scripts, or if PATH update failed during install, run dnv completion <yourShellName> to enable auto-completion. Bash, Zsh, and PowerShell 5.1+ are supported.

Updating

Denev includes a self-update command. When you need to get the latest version, you can run the following command:

dnv update

Tip: The update command accepts options — see the update section for details.

Uninstalling

To uninstall Denev, you can run the following commands:

Linux:

rm -f ~/.local/bin/dnv && rm -rf ~/.local/share/denev && rm -rf ~/.cache/denev-cli && rm -rf ~/.local/share/denev-cli && rm -rf ~/.config/denev-cli

macOS:

rm -f ~/.local/bin/dnv && rm -rf ~/.local/share/denev && rm -rf ~/Library/Caches/denev-cli && rm -rf ~/Library/Application\ Support/denev-cli && rm -rf ~/.config/denev-cli

Windows (PowerShell):

Remove-Item "$env:LOCALAPPDATA\denev" -Recurse -Force -ErrorAction SilentlyContinue
Remove-Item "$env:LOCALAPPDATA\denev-cli" -Recurse -Force -ErrorAction SilentlyContinue
Remove-Item "$env:USERPROFILE\.config\denev-cli" -Recurse -Force -ErrorAction SilentlyContinue

After running the commands for your OS, you may need to remove Denev from your shell config (~/.bashrc, ~/.zshrc, ~/.profile, etc.).

Note: Changes will be fully applied after starting a new terminal.

Warning: On Linux and macOS, paths depend on XDG_CONFIG_HOME, XDG_DATA_HOME, and XDG_CACHE_HOME when set. Check the actual locations with echo "$XDG_CONFIG_HOME" etc. before running the commands above.

Getting started

Denev mostly follows this shape:

dnv <module> <command> [arguments] [options]

Note: Some commands such as stats, update, or license use dnv <command> [arguments] [options] shape.

Start with a small inspection or conversion first, so you can get a feel for the syntax without worrying about side effects — none of these examples modify their inputs:

dnv uuid generate --type V7
dnv url inspect "https://example.com:8443/search?q=denev#docs"
dnv json get user::name '{"user":{"name":"Ari"}}'
dnv http status 429

When you script or automate tasks, pipe data through standard input whenever a command lets you omit the positional argument — that way you avoid temporary files — and pair it with quiet mode for machine-readable output:

printf '%s' '{"build":{"version":"1.0.0"}}' | dnv json get build::version -q
printf '%s' 'hello world' | dnv base64 encode -q

A typical workflow

1. Start by inspecting or validating a value — url inspect, uuid validate, jwt inspect, and json get are good entry points because they are read-only and let you verify your data first.
2. Reach for --quiet only when the command explicitly documents a machine-readable or raw output mode; otherwise the output may be formatted for a terminal and harder to parse.
3. Use -o, --output where the command supports it. Each command validates the extension you supply, so you will get a clear error if the format is not accepted.
4. Check the exit code in your scripts: 0 means success, any other value tells you what went wrong (the table in Concepts below gives the full list).

Concepts and conventions

Input

Many commands accept a positional value directly, but when you omit it they read from standard input instead — which means you can pipe data without creating a temporary file. Some commands use --file to treat that positional value as a file or directory path, so check each command’s card before assuming both forms work: not every command supports both.

Note: When a command accepts several positional values and supports piping, piped input always occupies the last position.

Output, files, and clipboard

Normal output is formatted for a terminal so you can read it at a glance, but that is not always what you want in a script. --quiet strips prompts and formatting, though what you get back — raw text, JSON, or simply an exit code — depends on the command, so check the command card rather than assuming. -c, --copy places a result on your clipboard wherever the command supports it. Copying requires exactly one result, so --copy cannot be combined with --quiet or multi-value output such as --repeat; individual cards only repeat this rule when a command-specific nuance exists.

Diagnostics never pollute your data: warnings and errors are written to stderr, so stdout carries only the command’s output — even when piped. --quiet strips formatting and prompts from stdout but never hides warnings since they are on stderr.

When a command writes a file, it infers the format from the extension you provide. If the file already exists, you are asked for confirmation unless you pass --force; if you decline, the command exits with code 4. When piping input, --force is required to overwrite an existing file because there is no terminal to prompt.

Exit codes

Modules

Command documentation

Every command card below follows the same reading order — description, syntax, arguments and options, then examples and notes — so once you have read one, you can find your way around any of them. Aliases invoke the same implementation, which means dnv cert gen behaves exactly like dnv cert generate.

dnv update

Description

Autonomously updates the CLI to the latest version or the targeted one.

Syntax

dnv update [options]

Arguments and options

Examples and notes

Use it to easily get up to date; the first example below updates the CLI to the latest version, while the second is targeting a specific version:

dnv update
dnv update --target 1.2.0

Note: If no specific target is given, the latest update will be downloaded.

Warning: When using --target to access an older version, note that only the four most recent documentation versions are available. Versions containing only bug fixes are not counted. Example: if the latest release is v2.0.3, the available documentation versions would be the latest patch release of each of the four most recent minor versions — v2.0.3, v1.9.8, v1.8.12, and v1.7.15 (assuming these versions exist).

dnv stats

Description

Analyzes a file or directory and produces language statistics, which is useful when you want a quick inventory of a codebase. If you do not supply a path, it analyzes the current directory by default.

Warning: All path arguments are resolved relative to the current working directory.

Syntax

dnv stats [path] [options]

Arguments and options

Examples and notes

Use it to get a quick project inventory; the first example below limits output to the top 8 languages and skips common generated folders, while the second exports to CSV for sharing:

dnv stats ./src --default-exclude --top 8
dnv stats . --no-comments -o statistics.csv

Tip: You should exclude generated folders explicitly if they matter to your repository, otherwise they may inflate the counts. A nonexistent positional path is a file I/O error (exit code 5), but an exclusion entry that matches nothing simply produces a warning on stderr — the command still succeeds.

Note: Supported extensions are .cs, .js, .ts, .jsx, .tsx, .html, .css, .scss, .sass, .py, .java, .kt, .kts, .c, .cpp, .go, .rs, .php, .rb, .swift, .dart, .lua, .sh, .ps1, .sql, .json, .jsonc, .xml, .yml, .yaml, .fs, .r, and .scala. Any extensions not mentioned here are neither analyzed nor counted.

dnv crypto

Use the crypto module whenever you need a digest or a keyed digest — from text, standard input, a file, or an entire directory — because it centralises what would otherwise require several different OS tools.

dnv crypto hash

Description

Creates a cryptographic hash of your input. SHA-256 is the default because it strikes a good balance between speed and security, but you can choose SHA-1 or MD5 too — the command will warn you, though, since neither is considered cryptographically safe for modern use.

Syntax

dnv crypto hash [input] [options]

Arguments and options

Examples and notes

Hash text or a file, then use --check where a single input is applicable:

dnv crypto hash 'release-candidate'
dnv crypto hash ./artifact.zip --file --algorithm SHA512
dnv crypto hash 'hello' --check 2cf24dba5fb0a30e26e83b2ac5b9e29e1b161e5c1fa7425e73043362938b9824 -q

Warning: Prefer SHA-256 or stronger. --check cannot be used with --copy and is restricted to a single input.

dnv crypto hmac

Description

Computes an HMAC for your text or files using a key that you supply directly or that the command prompts you for — which is useful when you need to verify message authenticity without exposing the key in your command history.

Syntax

dnv crypto hmac [input] [options]

Arguments and options

Examples and notes

Use an environment variable in non-interactive automation:

dnv crypto hmac 'payload' --key-env API_HMAC_KEY --algorithm SHA512
dnv crypto hmac ./payload.json --file --key-env API_HMAC_KEY -q

Warning: As with crypto hash, copy and check modes are restricted to a single input.

dnv color

The color module lets you check whether a foreground/background color pairing meets accessibility standards — it computes the WCAG contrast ratio and tells you instantly whether your colors pass or fail.

dnv color contrast

Description

Compares the contrast ratio of two colors against WCAG AA and AAA thresholds for both normal and large text.

Syntax

dnv color contrast <color1> [color2] [options]

Arguments and options

Examples and notes

dnv color contrast "#ff0000" "#00ff00" -q
dnv color contrast "rgb(255,0,0)" "hsl(120, 100%, 50%)" --background "hsv(0, 0%, 100%)"

Note: Colors can be expressed as hex (#RGB, #RGBA, #RRGGBB, #RRGGBBAA), rgb()/rgba(), hsl()/hsla(), or hsv()/hsva(). When a color has an alpha channel, --background is required to composite it before computing the contrast. If neither color has an alpha channel, --background is simply ignored.

Tip: Use --quiet to get a machine-readable JSON object with N_WCAG_AA, N_WCAG_AAA, L_WCAG_AA, and L_WCAG_AAA fields for scripting or CI accessibility checks. N stands for normal text (>= 16px) and L for large text (>= 18px, or >= 14px bold).

dnv jwt

The JWT module lets you create signed tokens and also decode or optionally verify them, so you can both generate and inspect tokens without switching between separate tools.

dnv jwt generate (alias: dnv jwt gen)

Description

Generates signed JWTs that include whatever JSON claims you need plus standard registered claims — useful when you are testing authentication or need to issue tokens in a script.

Syntax

dnv jwt generate [claims] [options]

Arguments and options

Examples and notes

Create a short-lived HMAC token:

dnv jwt generate '{"role":"reader"}' --secret-env JWT_SECRET --iss api --exp 30m
dnv jwt gen '{"role":"user"}' --secret-env JWT_SECRET --sub user-42 --aud dashboard -q

Warning: Use environment variables for non-interactive secrets. A missing or empty variable, invalid duration, unsupported algorithm, or incompatible signing inputs is an input error (2).

Tip: Claims can contain placeholders. Available placeholders are {{n}}, {{uuid}}, {{timestamp}}, and {{rand}}. {{n}} represents the current iteration number. {{uuid}} generate a new random at every iteration. {{timestamp}} uses the UTC Unix timestamp. {{rand}} uses a cryptographically secure 4 bytes string.

dnv jwt inspect

Description

Decodes a JWT so you can examine its header and payload, and can optionally verify it with a symmetric secret or public key to confirm the token has not been tampered with.

Syntax

dnv jwt inspect [token] [options]

Arguments and options

Examples and notes

dnv jwt inspect "$TOKEN"
dnv jwt inspect "$TOKEN" --secret-env JWT_SECRET --algorithm HS256

Note: When you inspect a token without supplying a verification key, the command decodes it so you can see the contents, but that alone does not establish trust — anyone could have created it. If the token is malformed, you get an input error (exit code 2); if verification fails because the signature does not match, you get exit code 1.

dnv base64 (alias module: dnv b64)

Use base64 whenever you need to convert text or raw file contents to or from Base64, and since typing base64 every time can feel long, the shorter alias b64 exposes the same encode/enc and decode/dec commands.

dnv base64 encode (aliases: enc, b64 encode, b64 enc)

Description

Encodes your text, stdin, or file or directory contents as classic Base64 or Base64URL — the --url flag lets you switch to the URL-safe variant, which is useful when you need to include the output in a URL or query parameter without worrying about + and / characters.

Syntax

dnv base64 encode [input] [options]

Arguments and options

Examples and notes

dnv base64 encode 'Hello world' -q
dnv b64 enc ./avatar.png --file -o avatar.b64

Note: --copy cannot be used for a folder or multiple paths.

dnv base64 decode (aliases: dec, b64 decode, b64 dec)

Description

Decodes classic Base64 or Base64URL input back into text or bytes, which is the counterpart to encode and supports the same options so you can round-trip data without surprises.

Syntax

dnv base64 decode [input] [options]

Arguments and options

Examples and notes

dnv base64 decode SGVsbG8gd29ybGQ= -q
dnv base64 dec 'aGVsbG8=' -u -o decoded.bin

Warning: Apply --url only when your input is Base64URL-encoded, because what works for one encoding will not produce the correct output for the other.

dnv regex

The regex module lets you test patterns, visualize their syntax tree, and manage named patterns you want to reuse — so instead of remembering which online tool you used last time, you have everything locally and offline.

dnv regex test

Description

Tests a regex pattern against input and reports matches, including support for the convenient /pattern/flags notation. It also performs compatibility and ReDoS-oriented analysis, which helps you catch performance issues or cross-engine incompatibilities before you deploy the pattern.

Syntax

dnv regex test <pattern> [input] [options]

Arguments and options

Examples and notes

dnv regex test '/\\d+/' 'order-42'
printf 'cat\ndog\n' | dnv regex test '/^d/' --all

Tip: Use a timeout for untrusted or expensive patterns. A regex timeout returns 3.

Note: --engine accepts aliases and is not case-sensitive. Aliases are ES for ECMAScript, py for Python, pcre for Pcre2, and Java for JavaPattern.

Warning: When stdout is piped, --quiet outputs only the exit code (0 for a match, 1 for no match). Otherwise, it returns a JSON string or just the exit code, depending on how many matches the pattern detects in the input.

dnv regex explain

Description

Visualizes a regex as an abstract syntax tree so you can inspect how the engine interprets grouping, alternation, and quantifiers — much clearer than staring at the raw pattern when you are debugging a complex expression.

Syntax

dnv regex explain [pattern] [options]

Arguments and options

Examples and notes

dnv regex explain '/^(?=.*\\d).{8,}$/' --engine Pcre2

Tip: Use this before sharing a complex expression: it exposes grouping and operators as parsed rather than merely reprinting the pattern.

dnv regex pattern

Description

Lets you save, list, retrieve, import, edit, and delete named regular expressions — essentially a local pattern library so you do not have to search for or rewrite the same expressions across projects.

Syntax

dnv regex pattern [pattern|name] [options]

Arguments and options

Examples and notes

dnv regex pattern '/^[^@]+@[^@]+$/' --save email
dnv regex pattern email -q
dnv regex pattern --del email

Note: all is reserved as a saved name and cannot be used for your own patterns. If you decline a deletion confirmation, the command returns exit code 4. Some action combinations — such as --save with --delete — are rejected because they conflict, so you can only perform one type of operation per invocation.

dnv uuid

Use the UUID commands whenever you need a unique identifier — whether you want a random V4, a name-based V5, or a time-ordered V7 — and you can also validate existing UUIDs or decode them to inspect their structure.

dnv uuid generate (alias: dnv uuid gen)

Description

Generates UUIDs according to your chosen version — V4 (random), V5 (name-based with a namespace), or V7 (timestamp-ordered) — so you can pick the type that fits your use case rather than relying on a single default.

Syntax

dnv uuid generate [V5_Name] [options]

Arguments and options

Examples and notes

dnv uuid generate --type V7
dnv uuid gen 'customer-42' --type V5 --namespace dns
dnv uuid generate -r 5 -o ids.urn

Note: V5 requires a name (as an argument or via stdin), while V4 and V7 reject supplied input — so you cannot pass a value to them. A namespace is only valid with V5.

dnv uuid validate

Description

Validates one or more UUIDs — either the value you pass directly or those found inside a file — which is useful when you need to check that an identifier conforms to a specific version before using it.

Syntax

dnv uuid validate [uuid|filePath] [options]

Arguments and options

Examples and notes

dnv uuid validate 550e8400-e29b-41d4-a716-446655440000 --type V4
dnv uuid validate ids.txt --file --type V4 V7 -q

Note: Invalid UUIDs and unknown type syntax are input errors (exit code 2); a missing file is exit code 5. --type accepts space-separated expected versions and is not restricted to V4, V5, or V7.

dnv uuid inspect

Description

Decodes and displays detailed information about a UUID — or about multiple UUIDs read from a file — so you can examine version, variant, and timestamp fields at a glance without having to parse the raw hex yourself.

Syntax

dnv uuid inspect [uuid|filePath] [options]

Arguments and options

Examples and notes

dnv uuid inspect 550e8400-e29b-41d4-a716-446655440000
dnv uuid inspect ids.txt --file -o inspection.json

Warning: Do not provide both an argument and piped input together, because the command requires a single input source to avoid ambiguity. Input that is not a valid UUID is rejected.

dnv cert

Use the cert module when you need a self-signed certificate for development or testing, cryptographic keys, or when you want to inspect a local certificate file or fetch one from a remote domain — so you can easily diagnose TLS issues.

dnv cert generate (alias: dnv cert gen)

Description

Generates a self-signed certificate along with its private key material, which is useful when you need a quick TLS certificate for local development without setting up a full CA infrastructure.

Syntax

dnv cert generate <outputPath> [subject] [options]

Arguments and options

Examples and notes

dnv cert generate dev.pem /CN=localhost --sans localhost 127.0.0.1 --server
dnv cert gen internal-ca.pem /CN=InternalCA --ca --days 3650

Note: PFX output and exported separate keys cannot be combined — choose one format. Quiet PFX generation requires --pw-env because there is no terminal to prompt for a password, so set the variable beforehand for non-interactive use.

dnv cert inspect

Description

Parses a local PEM, DER, or PFX certificate so you can examine its fields, or obtains a certificate directly from a domain — which saves you from having to download it separately when troubleshooting TLS.

Syntax

dnv cert inspect [certPath|domainName] [options]

Arguments and options

Examples and notes

dnv cert inspect ./server.pem --field expiry issuer
dnv cert inspect example.com --domain --warn-days 30 -q

Note: By default, the target port is 443 on HTTPS or 80 on HTTP. HTTP scheme must be explicit if not using HTTPS.

Note: PFX inspection in quiet mode requires --pw-env since no terminal is available to enter a password.

dnv random

The random module covers the kinds of random values you commonly need — strings, integers, bytes, passwords, and picks from a list. A --seed option is available on non-cryptographic generators so you can reproduce the same sequence when testing, but do not use it for secrets because seeded generators are not cryptographically secure.

dnv random string (alias: str)

Description

Generates random strings with a default length of 30 characters and an alphanumeric charset, though you can adjust both — useful when you need identifiers, tokens, or sample data on demand.

Syntax

dnv random string [options]

Arguments and options

Examples and notes

dnv random str --length 20 --charset upper
dnv random string --charset custom:ABC123 --seed 7 -r 3 -q

Note: Custom charsets must contain characters after custom:, or the charset is invalid.

dnv random int

Description

Generates a random 64-bit integer, optionally constrained to a range — so you can pick a port number between 1024 and 65535, for instance, without having to implement the random logic yourself.

Syntax

dnv random int [options]

Arguments and options

Examples and notes

dnv random int --limit 1:100
dnv random int --limit 0:255 -r 10 -o samples.json

Note: The minimum value cannot exceed the maximum in --limit <min:max>; the default range is -9223372036854775808 to 9223372036854775807. Output files must use the .json extension.

dnv random bytes

Description

Generates a specified number of random bytes, output as hex by default. Use --secure when you need cryptographically secure randomness — for keys, salts, or nonces — as opposed to the default pseudo-random generator which is faster but not suitable for security purposes.

Syntax

dnv random bytes [bytesCount] [options]

Arguments and options

Examples and notes

dnv random bytes 32 --secure -q
dnv random bytes 16 --format bin -o nonce.bin

Warning: Use --secure for keys, salts, or nonces — the default generator is not cryptographically secure. If using -o, --output to output a .hex file, the format must also be hex. --secure and --seed cannot be combined.

dnv random password (alias: pw)

Description

Generates cryptographically secure passwords using a strong random source, which is safer than rolling your own password generation in a script because it avoids predictable patterns.

Syntax

dnv random password [options]

Arguments and options

Examples and notes

dnv random pw --length 24 --copy
dnv random password --no-symbols --length 20 -r 5 -o passwords.json

Warning: Avoid printing a production password to a shared terminal where it could be visible to others.

dnv random pick

Description

Chooses one item at random from a space-separated list you provide, which is handy when you need to pick a winner, select a random configuration profile, or shuffle decision-making in a script.

Syntax

dnv random pick [choices] [options]

Arguments and options

Examples and notes

dnv random pick red green blue
dnv random pick a b c d --repeat 3 --seed 11 -q

Note: An empty list is invalid. Use --seed only for deterministic selection — never for secrets.

dnv time

The time module works with the three formats you are most likely to encounter — Unix timestamps, ISO 8601 strings, and the shorthand now — so you can convert, compare, or adjust time values without worrying about the format mismatch between different data sources. The --utc and --timezone options only apply when the input is now.

dnv time convert

Description

Converts a time value into the representation you need — ISO 8601, RFC 3339, Unix timestamp, or a local or UTC datetime — which saves you from having to look up the format string every time.

Syntax

dnv time convert [timeValue] [options]

Arguments and options

Examples and notes

dnv time convert 1719090000 --to iso
dnv time convert now --to rfc3339 --timezone Europe/Paris

Note: Provide the value as an argument or through stdin, but not both — the command requires a single input source.

Tip: --timezone is not case-sensitive.

dnv time diff

Description

Computes the difference between two time values and reports it in the unit you choose — useful when you need to measure elapsed time or check whether a deadline has passed.

Syntax

dnv time diff <timeA> [timeB] [options]

Arguments and options

Examples and notes

dnv time diff 1719090000 1719176400 --unit h
dnv time diff 2024-06-21T12:00:00Z now

Tip: Use --unit when your script needs a consistent unit for further processing, rather than parsing the human-readable default output.

dnv time add

Description

Adds a duration or individual time units to a given value, which is convenient when you want to compute an expiration date, schedule a future event, or shift a timestamp without date-math errors.

Syntax

dnv time add [timeValue] [options]

Arguments and options

Examples and notes

dnv time add now --days 7
dnv time add 2024-06-21T12:00:00Z --duration 1mo2d

Note: At least one unit is required — you cannot call the command with no time adjustment. Also, --duration cannot be mixed with individual unit options like --days or --hours because they represent two alternative ways to specify the same thing.

dnv http

The HTTP module gives you quick access to status codes, response headers, and endpoint timing — everything you need to diagnose a remote service without leaving the terminal. Network failures return exit code 6, while timeouts return exit code 3.

dnv http status

Description

Looks up what a status code or category means — useful when you encounter an unfamiliar code — or fetches the actual response status from a remote domain if you pass --domain.

Syntax

dnv http status [code|domainName] [options]

Arguments and options

Examples and notes

dnv http status 429
dnv http status 4xx
dnv http status example.com:8443 --domain -q

Note: By default, the target port is 443 on HTTPS or 80 on HTTP. HTTP scheme must be explicit if not using HTTPS.

dnv http headers

Description

Fetches the response headers a domain sends back, which helps you inspect caching policies, content types, or server identity without using a browser’s developer tools.

Syntax

dnv http headers [domainName] [options]

Arguments and options

Examples and notes

dnv http headers example.com --follow
dnv http headers example.com --header content-type -q

Note: By default, the target port is 443 on HTTPS or 80 on HTTP. HTTP scheme must be explicit if not using HTTPS.

Tip: Use --follow when a redirect response is not the final result you need — the command will follow the chain until it reaches a non-redirect status.

dnv http timing

Description

Measures each phase of the connection — DNS resolution, TCP handshake, TLS negotiation, time to first byte, and total response — so you can pinpoint where a slow endpoint is spending its time.

Syntax

dnv http timing [domainName] [options]

Arguments and options

Examples and notes

dnv http timing example.com
dnv http timing example.com:8443 --repeat 3 -q

Note: By default, the target port is 443 on HTTPS or 80 on HTTP. HTTP scheme must be explicit if not using HTTPS.

Tip: Use the quiet JSON output when you need to compare successive measurements in a script — it is easier to parse than the human-readable table.

dnv url

dnv url inspect

Description

Parses a URL into its components — scheme, host, port, path, query, and fragment — so you can examine or extract any part without writing your own URL parser or reaching for a browser.

Syntax

dnv url inspect [URL] [options]

Arguments and options

Examples and notes

dnv url inspect 'https://example.com:8443/path?q=hello&n=1#frag'
dnv url inspect /docs --base https://example.com --field host

Note: --field and --output cannot be combined because they target different output forms (one filters to a single field, the other writes a full JSON file). If you omit the extension on the output path, .json is added by default.

dnv url encode

Description

Encodes a string so it can be safely included in a URL, replacing characters that would otherwise be ambiguous or invalid — useful when you are building query strings or API calls in a script.

Syntax

dnv url encode [value] [options]

Arguments and options

Examples and notes

dnv url encode 'hello world&x=1' -q
dnv url encode 'q=hello world&lang=en' --component query

Note: full is the default component mode and encodes all characters that are not permitted in a URL. query mode is intended for encoding query string representations. Empty input is rejected.

dnv url decode

Description

Decodes URL-encoded text back to its original form, which is the counterpart to encode and works with the same component modes so you can safely round-trip values.

Syntax

dnv url decode [value] [options]

Arguments and options

Examples and notes

dnv url decode 'hello%20world%26x%3D1' --strict -q

dnv json

The JSON module lets you query values, pick or omit fields recursively, and compare documents semantically — so you can inspect and filter JSON data without piping or writing ad-hoc scripts. Note that file inputs require the --file flag where listed.

dnv json get

Description

Extracts values from a JSON document using a simple field name, a ::-separated path for exact navigation, or a full RFC 9535 JSONPath expression when you need more advanced queries — so you can pick the syntax that matches the complexity of your data.

Syntax

dnv json get <path> [JSON|JSON_File_Path] [options]

Arguments and options

Examples and notes

dnv json get name '{"user":{"name":"Alice"}}'
dnv json get user::name data.json --file
dnv json get '$..author' books.json --jsonpath --file -q

Note: With the default syntax, name searches recursively through all levels, while user::name follows an exact path. A query that finds no match is not an error — it simply returns nothing. Invalid JSON or JSONPath syntax produces error code 2.

dnv json pick

Description

Keeps only the fields you name, recursively, throughout the entire JSON document — useful when you want to strip down a large response to the few fields that matter before logging or displaying it.

Syntax

dnv json pick <fields> [JSON|JSON_File_Path] [options]

Arguments and options

Examples and notes

dnv json pick name version data.json --file
printf '%s' '{"id":1,"secret":"x"}' | dnv json pick id -q

Note: Parent branches that contain at least one matching field are retained, while branches with no matches are removed — so the overall structure is preserved where it matters. Output paths must use the .json extension.

dnv json omit

Description

Removes the fields you name, recursively, throughout the entire JSON document — the inverse of pick, useful when you want to redact sensitive fields like password or apiKey before sharing.

Syntax

dnv json omit <fields> [JSON|JSON_File_Path] [options]

Arguments and options

Examples and notes

dnv json omit password apiKey data.json --file -o sanitized.json

Tip: Use omit before logging or sharing JSON that contains sensitive fields — it saves you from having to manually redact values in a text editor.

dnv json diff

Description

Compares two JSON documents semantically — ignoring key order and formatting — and reports what was added, removed, or changed, which saves you from doing a manual diff when you need to verify that a transformation or API response has not introduced unexpected differences.

Syntax

dnv json diff <JSON-1|JSON_File_Path-1> [JSON-2|JSON_File_Path-2] [options]

Arguments and options

Examples and notes

dnv json diff before.json after.json --file
dnv json diff a.json b.json --file --ignore-array-order -q

Note: Object key order and whitespace formatting do not affect the comparison — only the actual values matter. Array order is significant unless you set --ignore-array-order. The first JSON document is always used as the reference.

Complete route and alias reference

FAQ

Why does a command reject both an argument and piped input?

Pipeable arguments requires a single input source to avoid ambiguity. Pass the value either as an argument or through stdin.

Why did --copy fail with --quiet or --repeat?

Commands that copy a result require exactly one interactive result. Generate one value without quiet mode, or write/pipe multiple values instead.

Why did my output path gain an extension?

Several commands add their documented default extension when the supplied output path has none. They reject unsupported extensions rather than silently changing the format. However, the extension may change if the output contains several elements.

Can I use MD5 or SHA-1?

crypto hash and crypto hmac support them, but the CLI identifies them as weak. Prefer SHA-256 or stronger; use --no-warn only when compatibility requires the older algorithm.

Does jwt inspect verify every token?

No. It decodes a token by itself. Supply a supported secret or public key and algorithm to verify a signature.

How do I diagnose an endpoint that fails?

Use dnv http status <domain> --domain for the status, dnv http headers <domain> for headers, and dnv http timing <domain> for phase timings. Exit code 3 indicates a timeout; 6 indicates a network failure.