minigrep

A simple command-line tool to search for a string within a file, inspired by the classic grep utility.

Usage

To run the program with Cargo, use the following format. Note the -- to separate the program arguments from Cargo's arguments.

cargo run -- <query> <filepath> [case_flag]

After building the project (cargo build --release), you can run the binary directly:

./target/release/minigrep <query> <filepath> [case_flag]

Arguments

• <query>: The string you want to find.
• <filepath>: The path to the file you want to search in.
• [case_flag] (Optional): Determines if the search is case-insensitive/smartcase/sensitive.
  • 0: case-insensitive search.
  • 1: search with smartcase (means: If your search pattern contains any uppercase letter, smartcase forces the search to be case-sensitive otherwise case-insensitive).
  • 2 or omitted: Defaults to a case-sensitive search.

Configuration via Environment Variables

You can also control case sensitivity by setting the CASE environment variable. This is useful for setting a default behavior for your entire shell session.

Example (on Linux/macOS):

# For a case-insensitive search by default
export CASE=0

# For searching with smartcase
export CASE=1

# For a case-sensitive search (by default)
export CASE=2

Note: A case_flag argument provided on the command line will always override the CASE environment variable for that specific command.