The processing performance of nl commands and commands with similar functions is summarized.

Processing speed ranking

The time required to add the line number of 1000000 lines of each implementation is summarized. The following alternative methods are also included in the comparison.

-Alternate nl command with various commands --Alternate nl command with script --Alternate nl command in editor

The GNU implementation occupies the top position. In GNU, cat -n and grep -n are faster than nl.

time(real)	command	version
0.372	ggrep	ggrep (GNU grep) 3.6
0.376	gcat	cat (GNU coreutils) 8.32
0.401	gnl	nl (GNU coreutils) 8.32
0.610	mawk	MAWK Version 1.3.4
0.676	nl	BSD
0.780	grep	grep (BSD grep) 2.5.1-FreeBSD
0.786	busybox nl(* Converted value)	BusyBox v1.30.1 (Ubuntu 1:1.30.1-4ubuntu6.3) multi-call binary.
1.021	cat	BSD
1.106	gawk	GNU Awk 5.1.0, API: 3.0 (GNU MPFR 4.1.0, GNU MP 6.2.1)
1.979	sed	BSD
1.996	gsed	gsed (GNU sed) 4.8
2.428	nawk	awk version 20070501 - one true awk(new awk)
2.751	perl	perl 5, version 32, subversion 0 (v5.32.0) built for darwin-thread-multi-2level
5.558	vim	VIM - Vi IMproved 8.2 (2019 Dec 12, compiled Nov 29 2020 16:14:01)

Implementation comparison

The measurement environment is as follows.

macOS 10.13.6 / Intel(R) Core(TM) i7-2677M CPU @ 1.80GHz (2C4T)
Ubuntu 20.04LTS / Intel(R) Core(TM) i5-2415M CPU @ 2.30GHz (2C4T)

Basically, it is measured on macOS, and only busybox is measured and converted on Ubuntu. (Busybox relies on Linux header files, which was annoying)

`nl` implementation comparison

coreutils vs BSD macOS 10.13.6 / Intel(R) Core(TM) i7-2677M CPU @ 1.80GHz (2C4T)

$ time seq 1000000 | nl >/dev/null

time	1	2	3	Ave.
real	0m0.678s	0m0.675s	0m0.676s	0.676
user	0m1.072s	0m1.065s	0m1.065s	1.067
sys	0m0.019s	0m0.020s	0m0.018s	0.019

$ time seq 1000000 | gnl >/dev/null

time	1	2	3	Ave.
real	0m0.401s	0m0.404s	0m0.399s	0.401
user	0m0.760s	0m0.770s	0m0.758s	0.763
sys	0m0.015s	0m0.015s	0m0.014s	0.015

coreutils vs busybox Ubuntu 20.04LTS / Intel(R) Core(TM) i5-2415M CPU @ 2.30GHz (2C4T)

$ time seq 1000000 | nl >/dev/null

time	1	2	3	Ave.
real	0m0.184s	0m0.183s	0m0.185s	0.184
user	0m0.188s	0m0.191s	0m0.189s	0.189
sys	0m0.018s	0m0.014s	0m0.018s	0.017

$ time seq 1000000 | busybox nl >/dev/null

time	1	2	3	Ave.
real	0m0.364s	0m0.363s	0m0.355s	0.361
user	0m0.376s	0m0.397s	0m0.378s	0.384
sys	0m0.029s	0m0.005s	0m0.005s	0.013

Comparison with other commands

This command was used in Substitute nl command with various commands. I haven't tried less. macOS 10.13.6 / Intel(R) Core(TM) i7-2677M CPU @ 1.80GHz (2C4T)

cat -n (coreutils vs BSD)

$ time seq 1000000 | gcat -n >/dev/null

time	1	2	3	Ave.
real	0m0.377s	0m0.373s	0m0.379s	0.376
user	0m0.410s	0m0.407s	0m0.413s	0.410
sys	0m0.017s	0m0.017s	0m0.017s	0.017

$ time seq 1000000 | cat -n >/dev/null

time	1	2	3	Ave.
real	0m1.026s	0m1.012s	0m1.026s	1.021
user	0m1.417s	0m1.396s	0m1.414s	1.409
sys	0m0.020s	0m0.020s	0m0.020s	0.020

grep -n (GNU vs BSD)

$ time seq 1000000 | ggrep -n ^ >/dev/null

time	1	2	3	Ave.
real	0m0.368s	0m0.370s	0m0.378s	0.372
user	0m0.365s	0m0.367s	0m0.374s	0.369
sys	0m0.015s	0m0.015s	0m0.016s	0.015

$ time seq 1000000 | grep -n ^ >/dev/null

time	1	2	3	Ave.
real	0m0.786s	0m0.774s	0m0.780s	0.780
user	0m1.160s	0m1.149s	0m1.167s	1.159
sys	0m0.019s	0m0.020s	0m0.020s	0.020

Comparison with script

This is the script one-liner used in Substitute nl command with script. macOS 10.13.6 / Intel(R) Core(TM) i7-2677M CPU @ 1.80GHz (2C4T)

Awk（gawk vs mawk vs nawk）

`gawk`


$ time seq 1000000 | gawk '$0=NR"\t"$0' >/dev/null

time	1	2	3	Ave.
real	0m1.103s	0m1.126s	0m1.089s	1.106
user	0m1.464s	0m1.528s	0m1.476s	1.489
sys	0m0.023s	0m0.022s	0m0.020s	0.022

`mawk`


$ time seq 1000000 | mawk '$0=NR"\t"$0' >/dev/null

time	1	2	3	Ave.
real	0m0.609s	0m0.613s	0m0.609s	0.610
user	0m1.000s	0m1.006s	0m1.005s	1.004
sys	0m0.021s	0m0.021s	0m0.021s	0.021

`nawk`


$ time seq 1000000 | /usr/bin/awk '$0=NR"\t"$0' >/dev/null

time	1	2	3	Ave.
real	0m2.444s	0m2.460s	0m2.379s	2.428
user	0m2.845s	0m2.866s	0m2.790s	2.834
sys	0m0.039s	0m0.033s	0m0.036s	0.036

Perl

$ time seq 1000000 | perl -pe 's/^/$.\t/' >/dev/null

time	1	2	3	Ave.
real	0m2.709s	0m2.776s	0m2.768s	2.751
user	0m3.078s	0m3.160s	0m3.147s	3.128
sys	0m0.035s	0m0.030s	0m0.030s	0.032

Comparison with editor

This is the editor used in Substitute nl command with editor. macOS 10.13.6 / Intel(R) Core(TM) i7-2677M CPU @ 1.80GHz (2C4T)

SED（GNU vs BSD）

$ time seq 1000000 | gsed = | paste - - >/dev/null

time	1	2	3	Ave.
real	0m1.994s	0m1.996s	0m1.997s	1.996
user	0m3.047s	0m3.069s	0m3.052s	3.056
sys	0m0.033s	0m0.035s	0m0.037s	0.035

$ time seq 1000000 | sed = | paste - - >/dev/null

time	1	2	3	Ave.
real	0m1.974s	0m1.991s	0m1.973s	1.979
user	0m3.014s	0m3.047s	0m3.026s	3.029
sys	0m0.043s	0m0.043s	0m0.044s	0.043

Strictly speaking, it also depends on the implementation of paste.

Vim

$ time seq 1000000 | vim -es /dev/stdin +':set number' +%p +q! >/dev/null

time	1	2	3	Ave.
real	0m5.580s	0m5.551s	0m5.543s	5.558
user	0m4.918s	0m4.916s	0m4.928s	4.921
sys	0m0.778s	0m0.743s	0m0.725s	0.749

nl command processing performance

Processing speed ranking

Implementation comparison

nl implementation comparison