CHAPTER 01 / 05
Arguments, options, and flags
Parse Rust command-line arguments with clap derive. Examples cover flags, defaults, optional values, typed validation, lists, and help text.
Rust reference
clap
cheat sheet.
Arguments, subcommands, validation, output handling, shell completions, and tests for Rust command-line tools.
27 topics54 code examplesUpdated
How clap fits together
01Describe the inputsFields and attributes define what the user can type.
02Parse and validateClap converts command words into typed values.
03Do the workYour program handles files, services, and errors.
04Write the resultSend data to stdout and diagnostics to stderr.
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5 chapters · 27 topics
CHAPTER 02 / 05
Subcommands and shared options
Build clap subcommands with shared options, argument groups, conflicts, and environment defaults. Handle paths and trailing arguments.
CHAPTER 03 / 05
Output, errors, and exit codes
Handle clap parse errors and exit codes in Rust. Send results to stdout, diagnostics to stderr, and write output files with examples.
CHAPTER 04 / 05
Builder API and advanced arguments
Use the clap builder API for dynamic commands and advanced arguments. Add JSON output, anyhow errors, and verbosity flags to a Rust CLI.
CHAPTER 05 / 05
Shell completion and CLI testing
Generate clap shell completions and man pages, test a CLI with assert_cmd, and follow a complete Rust file-search command example.
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