1_result.md

$ du -sbh ./input.txt;
# 209M ./input.txt

$ ./benchmark.sh ./input.txt;

Benchmark 1: tr -s \n
  Time (mean ± σ):     852.3 ms ±   9.8 ms    [User: 823.6 ms, System: 28.4 ms]
  Range (min … max):   841.4 ms … 871.8 ms    10 runs
 
Benchmark 2: grep -vx ''
  Time (mean ± σ):     564.1 µs ±  35.2 µs    [User: 306.6 µs, System: 221.7 µs]
  Range (min … max):   490.5 µs … 1008.2 µs    4622 runs
 
  Warning: Statistical outliers were detected. Consider re-running this benchmark on a quiet system without any interferences from other programs. It might help to use the '--warmup' or '--prepare' options.
 
Benchmark 3: grep -v '^$'
  Time (mean ± σ):     566.3 µs ±  34.5 µs    [User: 308.2 µs, System: 221.7 µs]
  Range (min … max):   499.9 µs … 949.6 µs    5425 runs
 
  Warning: Statistical outliers were detected. Consider re-running this benchmark on a quiet system without any interferences from other programs. It might help to use the '--warmup' or '--prepare' options.
 
Benchmark 4: sed '/^$/d'
  Time (mean ± σ):      2.438 s ±  0.008 s    [User: 2.394 s, System: 0.043 s]
  Range (min … max):    2.427 s …  2.455 s    10 runs
 
Benchmark 5: awk NF
  Time (mean ± σ):      4.090 s ±  0.031 s    [User: 4.048 s, System: 0.041 s]
  Range (min … max):    4.062 s …  4.152 s    10 runs
 
Summary
  grep -vx '' ran
    1.00 ± 0.09 times faster than grep -v '^$'
 1510.85 ± 95.89 times faster than tr -s \n
 4321.33 ± 270.15 times faster than sed '/^$/d'
 7250.52 ± 455.97 times faster than awk NF

2_benchmark.sh

#!/usr/bin/env bash

declare -r _commands=(
    'tr -s \n'
    "grep -vx ''"
    "grep -v '^\$'"
    "sed '/^\$/d'"
    'awk NF'
)

_Main()
{
    declare __filepath="$1";
    shift || return 2;

    hyperfine -N --warmup 3 \
        --input "$__filepath" \
        "${_commands[@]}";
}

_Main "$@";

3_generate_input.php

#!/usr/bin/env php

$count = 30000000;

$f = fopen('./input.txt',"wb");

for ($i=0; $i < $count; $i++) {
    $line = mt_rand(1, 10) > 3 ? "some line\n" : "\n";
    fwrite($f, $line);
}
  
fclose($f);