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Building CLI Tools with Rust
Practical command-line tools with clap + serde
Famous Rust CLI tools: ripgrep (grep replacement), fd (find replacement), bat (cat replacement), exa (ls replacement). There's a reason they're faster than originals.
Single binary distribution — no runtime installation like Python. Startup time in milliseconds means no perceived delay when called from shell scripts.
Basic Structure
use clap::Parser;
#[derive(Parser)]
struct Cli {
#[arg(short, long)]
input: String,
}
clap's derive macros make argument parsing a struct definition. serde handles JSON/TOML/YAML I/O in one line.
Key Points
1
Create project with cargo new mytool
2
Define CLI argument struct with clap derive
3
Serialize config/data with serde
4
Build optimized binary with cargo build --release
Pros
- ✓ Single binary — deployment is one file
- ✓ Startup ~1ms — fast even when called from shell scripts
Cons
- ✗ Long compile times — minutes with many dependencies
- ✗ Cross-compilation gets complex with C dependencies
Use Cases
ripgrep — search multi-GB codebases in seconds
Data pipelines — JSON/CSV transformation CLI