tac_k_lib

Function reverse_file

Source 
pub fn reverse_file<W: Write, P: AsRef<Path>>(
    writer: &mut W,
    path: Option<P>,
    separator: u8,
) -> Result<()>
Expand description

Write the reversed content from path into writer, last line first.

If path is Some(_), read from the file at the specified path. If path is None, read from stdin instead.

separator is used to partition the content into lines. This is normally the newline character, b'\n'.

Internally it uses the following instruction set extensions to enable SIMD acceleration if available at runtime:

  • AVX2/LZCNT(ABM)/BMI2 on x64/x64_84
  • NEON on AArch64

ยงExample

use tac_k::reverse_file;
use std::path::Path;

// Read from `README.md` file, separated by '.'.
let mut result = vec![];
reverse_file(&mut result, Some("README.md"), b'.').unwrap();

assert!(std::str::from_utf8(&result).is_ok());

// Read from stdin.
let mut result = vec![];
reverse_file(&mut result, None::<&str>, b'.').unwrap();

assert!(result.is_empty());