Command Line Interface¶

pyheaderparse provides a command-line interface for quick header and cookie parsing.

Installation¶

The CLI is automatically installed when you install the package:

pip install pyheaderparse

Verify installation:

$ pyheaderparse --version
pyheaderparse 1.0.0

$ pyheaderparse --help

General Usage¶

pyheaderparse <command> [options]

Available Commands¶

parse - Parse HTTP headers
cookies - Parse cookies
info - Show header metadata/info

Global Options¶

-v, --version - Show version
-h, --help - Show help

Parse Command¶

Parse HTTP headers from a file or stdin.

Basic Usage¶

# Parse from file
$ pyheaderparse parse -f headers.txt

# Parse from stdin
$ cat headers.txt | pyheaderparse parse --stdin

# Parse inline data
$ pyheaderparse parse "content-type: application/json"

Options¶

-f, --file FILE     Read headers from file
--stdin             Read headers from stdin
-H, --header NAME   Get specific header only
-F, --format FORMAT Output format: json (default), raw, repr

Examples¶

Parse all headers (JSON output):

$ pyheaderparse parse -f headers.txt

{
  "content-type": {
    "value": "application/json",
    "params": {}
  },
  "content-length": 1024,
  "user-agent": "Mozilla/5.0",
  "accept": [
    {"type": "*/*", "q": 1.0}
  ],
  "dnt": true
}

Get specific header:

$ pyheaderparse parse -f headers.txt --header user-agent
"Mozilla/5.0 (Windows NT 10.0; Win64; x64) Chrome/144.0.0.0"

$ pyheaderparse parse -f headers.txt --header content-length
1024

$ pyheaderparse parse -f headers.txt --header accept
[{"type": "*/*", "q": 1.0}]

Raw output format:

$ pyheaderparse parse -f headers.txt --format raw
content-type: application/json
content-length: 1024
user-agent: Mozilla/5.0
accept: [{'type': '*/*', 'q': 1.0}]
dnt: True

From stdin:

$ echo -e "content-type: text/html\naccept: */*" | pyheaderparse parse --stdin
{
  "content-type": {
    "value": "text/html",
    "params": {}
  },
  "accept": [
    {"type": "*/*", "q": 1.0}
  ]
}

From clipboard (with xclip on Linux):

$ xclip -selection clipboard -o | pyheaderparse parse --stdin

Cookies Command¶

Parse cookies from header data or cookie files.

Basic Usage¶

# Parse from full headers file
$ pyheaderparse cookies -f headers.txt --full-headers

# Parse from cookie-only file
$ pyheaderparse cookies -f cookies.txt

Options¶

-f, --file FILE     Read from file
--stdin             Read from stdin
--full-headers      Input is full headers (not just cookies)
--as-header         Output as Cookie header format
-c, --cookie NAME   Get specific cookie only
-F, --format FORMAT Output format: json (default), raw, repr

Examples¶

Parse cookies from headers file:

$ pyheaderparse cookies -f headers.txt --full-headers

{
  "session": "abc123",
  "user": "john",
  "token": "xyz789",
  "csrf": "a9a6c92dc170"
}

Output as Cookie header format:

$ pyheaderparse cookies -f headers.txt --full-headers --as-header
session=abc123; user=john; token=xyz789; csrf=a9a6c92dc170

Get specific cookie:

$ pyheaderparse cookies -f headers.txt --full-headers -c session
abc123

$ pyheaderparse cookies -f headers.txt --full-headers -c user
john

Parse cookie-only file:

If your file contains only cookie lines:

# cookies.txt
cookie: session=abc123
cookie: user=john

$ pyheaderparse cookies -f cookies.txt
{
  "session": "abc123",
  "user": "john"
}

Parse single-line cookies:

$ echo "cookie: a=1; b=2; c=3" | pyheaderparse cookies --stdin
{
  "a": "1",
  "b": "2",
  "c": "3"
}

Info Command¶

Display metadata and information about headers.

Basic Usage¶

$ pyheaderparse info -f headers.txt

Options¶

-f, --file FILE     Read from file
--stdin             Read from stdin
-F, --format FORMAT Output format: json (default), raw, repr

Example Output¶

$ pyheaderparse info -f headers.txt

{
  "total_headers": 15,
  "total_cookies": 4,
  "content_type": "application/json",
  "content_length": 1171,
  "user_agent": "Mozilla/5.0 (Windows NT 10.0; Win64; x64) Chrome/144.0.0.0",
  "origin": "https://medium.com",
  "is_cors": true,
  "sec_fetch": {
    "site": "same-origin",
    "mode": "cors",
    "dest": "empty",
    "user": ""
  },
  "client_hints": {
    "sec-ch-ua": [
      {"brand": "Chrome", "version": "144"},
      {"brand": "Not A Brand", "version": "8"}
    ],
    "sec-ch-ua-mobile": false,
    "sec-ch-ua-platform": "Windows",
    "sec-ch-ua-arch": "x86",
    "sec-ch-ua-bitness": "64"
  }
}

Sample Headers File¶

Create a sample headers.txt file for testing:

content-length: 1171
content-type: application/json
user-agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) Chrome/144.0.0.0
accept: */*
accept-language: en-US,en;q=0.9
accept-encoding: gzip, deflate, br
cache-control: max-age=3600, public
dnt: 1
sec-ch-ua: "Chrome";v="144", "Not A Brand";v="8"
sec-ch-ua-mobile: ?0
sec-ch-ua-platform: "Windows"
sec-fetch-site: same-origin
sec-fetch-mode: cors
sec-fetch-dest: empty
origin: https://example.com
referer: https://example.com/page
cookie: session=abc123
cookie: user=john
cookie: token=xyz789

Piping and Scripting¶

The CLI works well in shell pipelines:

Extract specific values:

# Get just the user-agent string
$ pyheaderparse parse -f headers.txt -H user-agent -F raw

# Count cookies
$ pyheaderparse cookies -f headers.txt --full-headers | jq 'keys | length'

Use with curl:

# Save response headers
$ curl -sI https://example.com > response_headers.txt

# Parse them
$ pyheaderparse parse -f response_headers.txt

Use with httpie:

# Get headers from httpie
$ http --print=h GET https://httpbin.org/get > headers.txt
$ pyheaderparse info -f headers.txt

Process multiple files:

# Parse multiple header files
$ for f in *.headers; do
    echo "=== $f ==="
    pyheaderparse parse -f "$f" -H content-type
done

Exit Codes¶

0 - Success
1 - Error (file not found, invalid input, etc.)

$ pyheaderparse parse -f nonexistent.txt
Error: File 'nonexistent.txt' not found

$ echo $?
1