parsm - Parse 'Em - An 'everything' parser, Sedder, Awkker, Grokker, Grepper

Parsm is the powerful command-line tool that understands structured text better than sed, awk, grep or grok.

Overview

parsm automatically detects and parses multiple data formats (JSON, CSV, YAML, TOML, logfmt, and plain text) and provides powerful filtering and templating capabilities through an intuitive syntax.

By default, parsm outputs the original input when a filter matches. For custom output formatting, use templates.

0.8.3 removed a legacy fallback parser that could silently mis-parse certain filter/template expressions; parsing now runs entirely through one grammar. See CHANGELOG.md for the full list of fixes.

Installation

From crates.io

cargo install parsm

From source

cargo install --path .

Or build from source:

git clone <repository-url>
cd parsm
cargo build --release
./target/release/parsm --examples

Quick Start

# Basic usage
parsm [OPTIONS] [EXPR] [TEMPLATE]

# Examples
parsm --examples

# Extract a field
echo '{"name": "Alice"}' | parsm 'name'

# Nested fields
echo '{"user": {"email": "alice@example.com"}}' | parsm 'user.email'

# Filtering
echo '{"age": 30}' | parsm 'age > 25'

# Filter and format
echo '{"name": "Alice", "age": 30}' | parsm 'age > 25 [${name} is ${age}]'

# Read input from a file instead of stdin
parsm -f package.json 'name'

Supported Formats

• JSON
• CSV
• YAML
• TOML
• Logfmt
• Plain Text

Syntax Reference

See doc/syntaxfieldselector.md for the full field-selection design rationale and syntax walkthrough.

Filters

• Comparison: ==, !=, <, <=, >, >=
• String ops: *= (contains), ^= (starts with), $= (ends with), ~= (regex match)
• Boolean logic: &&, ||, !
• Truthy check: field?

Examples:

name == "Alice" && age > 25
email ~ "@example.com"
user.active?

Templates

• Variables: [${name}] or $name
• Literal: [name]

Example:

parsm 'age > 25 [${name} is ${age}]'

Field Selectors

• Simple: name
• Nested: user.email
• Quoted (special chars): 'special-field'
• CSV/Text: field_0, word_0

Examples

JSON/YAML/TOML

cat Cargo.toml | parsm 'package.name'
echo '{"user": {"email": "alice@example.com"}}' | parsm 'user.email'

CSV

echo 'Alice,30,Engineer' | parsm 'field_1 > "25" [${1} (${2})]'

Logs

echo 'level=error msg="DB error"' | parsm 'level == "error" [${msg}]'

CLI

parsm [OPTIONS] [EXPR] [TEMPLATE]

Arguments:
  [EXPR]      Expression: field selector, filter, template, or filter+template (optional)
  [TEMPLATE]  Template expression for output formatting (optional)

Options:
  -f, --file <FILE>  Read input from FILE instead of stdin (repeatable; '-' = stdin)
      --examples  Show usage examples
      --json      Force JSON format detection
      --yaml      Force YAML format detection
      --csv       Force CSV format detection
      --toml      Force TOML format detection
      --logfmt    Force logfmt format detection
      --text      Force plain text format detection
  -h, --help      Print help
  -V, --version   Print version

Comparison with Other Tools

Feature	parsm	jq	awk	sed
Multi-format	✅ JSON, CSV, YAML, TOML, logfmt, text	JSON only	Text	Text
Auto-detection	✅ Automatic	❌ Manual	❌ Manual	❌ Manual
Field extraction	✅ Simple name syntax	✅ .name syntax	Limited	❌ No
Simple syntax	✅ Low	Medium	Complex	Medium

Development

• Build: cargo build
• Test: cargo test
• Lint: cargo fmt && cargo clippy

Contributing

1. Fork repository
2. Create feature branch
3. Write tests and code
4. Run tests and lint checks
5. Submit a pull request

Crates.io

crates.io docs.rs

License

See LICENSE.

Changelog

See CHANGELOG.md.

Examples

# Basic filtering - outputs original input when filter matches
echo '{"name": "Alice", "age": 30}' | parsm 'age > 25'
# Output: {"name": "Alice", "age": 30}

# Filtering with custom template
echo '{"name": "Alice", "age": 30}' | parsm 'age > 25 [${name} is ${age}]'
# Output: Alice is 30

# Access original input in templates with ${0}
echo '{"name": "Alice", "age": 30}' | parsm '[Original: ${0}, Name: ${name}]'
# Output: Original: {"name": "Alice", "age": 30}, Name: Alice