Sloc Cloc and Code (scc)
A tool similar to cloc, sloccount and tokei. For counting physical the lines of code, blank lines, comment lines, and physical lines of source code in many programming languages.
Goal is to be the fastest code counter possible, but also perform COCOMO calculation like sloccount and to estimate code complexity similar to cyclomatic complexity calculators. In short one tool to rule them all.
Also it has a very short name which is easy to type scc
.
If you don't like sloc cloc and code feel free to use the name Succinct Code Counter
.
Dual-licensed under MIT or the UNLICENSE.
Install
Go Get
If you are comfortable using Go and have >= 1.10 installed:
$ go get -u github.com/boyter/scc/
Snap
A snap install exists thanks to Ricardo.
$ sudo snap install scc
Homebrew
$ brew install scc
Manual
Binaries for Windows, GNU/Linux and macOS for both i386 and x86_64 machines are available from the releases page.
Other
If you would like to assist with getting scc
added into apt/chocolatey/etc... please submit a PR or at least raise an issue with instructions.
Background
Read all about how it came to be along with performance benchmarks,
- https://boyter.org/posts/sloc-cloc-code/
- https://boyter.org/posts/why-count-lines-of-code/
- https://boyter.org/posts/sloc-cloc-code-revisited/
- https://boyter.org/posts/sloc-cloc-code-performance/
- https://boyter.org/posts/sloc-cloc-code-performance-update/
Some reviews of scc
- https://nickmchardy.com/2018/10/counting-lines-of-code-in-koi-cms.html
- https://www.feliciano.tech/blog/determine-source-code-size-and-complexity-with-scc/
For performance see the Performance section
Other similar projects,
- cloc the original sloc counter
- gocloc a sloc counter in Go inspired by tokei
- loc rust implementation similar to tokei but often faster
- loccount Go implementation written and maintained by ESR
- ployglot ATS sloc counter
- sloccount written as a faster cloc
- tokei fast, accurate and written in rust
Interesting reading about other code counting projects tokei, loc, polyglot and loccount
- https://www.reddit.com/r/rust/comments/59bm3t/a_fast_cloc_replacement_in_rust/
- https://www.reddit.com/r/rust/comments/82k9iy/loc_count_lines_of_code_quickly/
- http://blog.vmchale.com/article/polyglot-comparisons
- http://esr.ibiblio.org/?p=8270
Further reading about processing files on the disk performance
Pitch
Why use scc
?
- It is very fast and gets faster the more CPU you throw at it
- Accurate
- Works very well across multiple platforms without slowdown (Windows, Linux, macOS)
- Large language support
- Can ignore duplicate files
- Has complexity estimations
- You need to tell the difference between Coq and Verilog in the same directory
Why not use scc
?
- You don't like Go for some reason
- It cannot count D source with different nested multi-line comments correctly boyter#27
Usage
Command line usage of scc
is designed to be as simple as possible.
Full details can be found in scc --help
or scc -h
.
Sloc, Cloc and Code. Count lines of code in a directory with complexity estimation.
Ben Boyter <[email protected]> + Contributors
Usage:
scc [flags]
Flags:
--avg-wage int average wage value used for basic COCOMO calculation (default 56286)
--binary disable binary file detection
--by-file display output for every file
--ci enable CI output settings where stdout is ASCII
--debug enable debug output
--exclude-dir strings directories to exclude (default [.git,.hg,.svn])
--file-gc-count int number of files to parse before turning the GC on (default 10000)
-f, --format string set output format [tabular, wide, json, csv, cloc-yaml] (default "tabular")
-h, --help help for scc
-i, --include-ext strings limit to file extensions [comma separated list: e.g. go,java,js]
-l, --languages print supported languages and extensions
--no-cocomo remove COCOMO calculation output
-c, --no-complexity skip calculation of code complexity
-d, --no-duplicates remove duplicate files from stats and output
--no-gitignore disables .gitignore file logic
--no-ignore disables .ignore file logic
-M, --not-match stringArray ignore files and directories matching regular expression
-o, --output string output filename (default stdout)
-s, --sort string column to sort by [files, name, lines, blanks, code, comments, complexity] (default "files")
-t, --trace enable trace output. Not recommended when processing multiple files
-v, --verbose verbose output
--version version for scc
-w, --wide wider output with additional statistics (implies --complexity)
Output should look something like the below for the redis project
$ scc .
───────────────────────────────────────────────────────────────────────────────
Language Files Lines Blanks Comments Code Complexity
───────────────────────────────────────────────────────────────────────────────
C 258 153080 17005 26121 109954 27671
C Header 200 28794 3252 5877 19665 1557
TCL 101 17802 1879 981 14942 1439
Shell 36 1109 133 252 724 118
Lua 20 525 68 70 387 65
Autoconf 18 10821 1026 1326 8469 951
Makefile 10 1082 220 103 759 51
Ruby 10 778 78 71 629 115
Markdown 9 1935 527 0 1408 0
gitignore 9 120 16 0 104 0
HTML 5 9658 2928 12 6718 0
C++ 4 286 48 14 224 31
License 4 100 20 0 80 0
YAML 4 266 20 3 243 0
CSS 2 107 16 0 91 0
Python 2 219 39 18 162 68
Batch 1 28 2 0 26 3
C++ Header 1 9 1 3 5 0
Extensible Styleshe… 1 10 0 0 10 0
Plain Text 1 23 7 0 16 0
Smarty Template 1 44 1 0 43 5
m4 1 562 116 53 393 0
───────────────────────────────────────────────────────────────────────────────
Total 698 227358 27402 34904 165052 32074
───────────────────────────────────────────────────────────────────────────────
Estimated Cost to Develop $5,755,686
Estimated Schedule Effort 29.835114 months
Estimated People Required 22.851995
───────────────────────────────────────────────────────────────────────────────
Note that you don't have to specify the directory you want to run against. Running scc
will assume you want to run against the current directory.
You can also run against multiple files or directories scc directory1 directory2 file1 file2
with the results aggregated in the output.
Interesting Use Cases
Used inside Intel Nemu Hypervisor to track code changes between revisions https://github.com/intel/nemu/blob/topic/virt-x86/tools/cloc-change.sh#L9 Appears to also be used inside both http://codescoop.com/ and https://pinpoint.com/
Features
scc
uses a small state machine in order to determine what state the code is when it reaches a newline \n
. As such it is aware of and able to count
- Single Line Comments
- Multi Line Comments
- Strings
- Multi Line Strings
- Blank lines
Because of this it is able to accurately determine if a comment is in a string or is actually a comment.
It also attempts to count the complexity of code. This is done by checking for branching operations in the code. For example, each of the following for if switch while else || && != ==
if encountered in Java would increment that files complexity by one.
Complexity Estimates
Lets take a minute to discuss the complexity estimate itself.
The complexity estimate is really just a number that is only comparable to files in the same language. It should not be used to compare languages directly without weighting them. The reason for this is that its calculated by looking for branch and loop statements in the code and incrementing a counter for that file.
Because some languages don't have loops and instead use recursion they can have a lower complexity count. Does this mean they are less complex? Probably not, but the tool cannot see this because it does not build an AST of the code as it only scans through it.
Generally though the complexity there is to help estimate between projects written in the same language, or for finding the most complex file in a project scc --by-file -s complexity
which can be useful when you are estimating on how hard something is to maintain, or when looking for those files that should probably be refactored.
Performance
Generally scc
will the fastest code counter compared to any I am aware of and have compared against. The below comparisons are taken from the fastest alternative counters. See Other similar projects
above to see all of the other code counters compared against. It is designed to scale to as many CPU's cores as you can provide.
However if you want greater performance and you have RAM to spare you can disable the garbage collector like the following on linux GOGC=-1 scc .
which should speed things up considerably. For some repositories turning off the code complexity calculation via -c
can reduce runtime as well.
Benchmarks are run on fresh 32 CPU Optimised Digital Ocean Virtual Machine 2019/03/04 all done using hyperfine with 3 warm-up runs and 10 timed runs.
scc v2.2.0 (compiled with Go 1.12)
tokei v9.0.0 (compiled with Rust 1.33)
loc v0.5.0 (compiled with Rust 1.33)
polyglot v0.5.19 (downloaded from github)
https://github.com/antirez/redis/
RedisProgram | Runtime |
---|---|
scc | 24.0 ms ± 2.7 ms |
scc (no complexity) | 18.9 ms ± 2.2 ms |
tokei | 26.6 ms ± 3.3 ms |
loc | 80.1 ms ± 54.7 ms |
polyglot | 15.0 ms ± 1.1 ms |
https://github.com/python/cpython
CPythonProgram | Runtime |
---|---|
scc | 64.3 ms ± 6.3 ms |
scc (no complexity) | 53.8 ms ± 6.5 ms |
tokei | 74.9 ms ± 11.6 ms |
loc | 155.1 ms ± 58.9 ms |
polyglot | 83.9 ms ± 9.4 ms |
https://github.com/torvalds/linux
Linux KernelProgram | Runtime |
---|---|
scc | 537.3 ms ± 33.1 ms |
scc (no complexity) | 438.9 ms ± 30.3 ms |
tokei | 525.9 ms ± 32.7 ms |
loc | 1.543 s ± 0.059 s |
polyglot | 1.022 s ± 0.056 s |
If you enable duplicate detection expect performance to fall by about 50%
CI/CD Support
Some CI/CD systems which will remain nameless do not work very well with the box-lines used by scc
. To support those systems better there is an option --ci
which will change the default output to ASCII only.
$ scc --ci main.go
-------------------------------------------------------------------------------
Language Files Lines Blanks Comments Code Complexity
-------------------------------------------------------------------------------
Go 1 171 6 4 161 2
-------------------------------------------------------------------------------
Total 1 171 6 4 161 2
-------------------------------------------------------------------------------
Estimated Cost to Develop $3,969
Estimated Schedule Effort 1.876811 months
Estimated People Required 0.250551
-------------------------------------------------------------------------------
API Support
The core part of scc
which is the counting engine is exposed publicly to be integrated into other Go applications. See https://github.com/pinpt/ripsrc for an example of how to do this. However as a quick start consider the following,
package main
import (
"fmt"
"io/ioutil"
"github.com/boyter/scc/processor"
)
type statsProcessor struct{}
func (p *statsProcessor) ProcessLine(job *processor.FileJob, currentLine int64, lineType processor.LineType) bool {
switch lineType {
case processor.LINE_BLANK:
fmt.Println(currentLine, "lineType", "BLANK")
case processor.LINE_CODE:
fmt.Println(currentLine, "lineType", "CODE")
case processor.LINE_COMMENT:
fmt.Println(currentLine, "lineType", "COMMENT")
}
return true
}
func main() {
bts, _ := ioutil.ReadFile("somefile.go")
t := &statsProcessor{}
filejob := &processor.FileJob{
Filename: "test.go",
Language: "Go",
Content: bts,
Callback: t,
}
processor.ProcessConstants() // Required to load the language information and need only be done once
processor.CountStats(filejob)
}
Adding/Modifying Languages
To add or modify a language you will need to edit the languages.json
file in the root of the project, and then run go generate
to build it into the application. You can then go install
or go build
as normal to produce the binary with your modifications.
Issues
Its possible that you may see the counts vary between runs. This usually means one of two things. Either something is changing or locking the files under scc, or that you are hitting ulimit restrictions. To change the ulimit see the following links.
- https://superuser.com/questions/261023/how-to-change-default-ulimit-values-in-mac-os-x-10-6#306555
- https://unix.stackexchange.com/questions/108174/how-to-persistently-control-maximum-system-resource-consumption-on-mac/221988#221988
- https://access.redhat.com/solutions/61334
- https://serverfault.com/questions/356962/where-are-the-default-ulimit-values-set-linux-centos
- https://www.tecmint.com/increase-set-open-file-limits-in-linux/
To help identify this issue run scc like so scc -v .
and look for the message too many open files
in the output. If it is there you can rectify it by setting your ulimit to a higher value.
Low Memory
If you are running scc
in a low memory environment < 512 MB of RAM you may need to set --filegccount
or --fgc
to a lower value such as 0
to force the garbage collector to be on at all times.
A sign that this is required will be scc
crashing with panic errors.
Tests
scc is pretty well tested with many unit, integration and benchmarks to ensure that it is fast and complete.
Package
Run go build for windows and linux then the following in linux, keep in mind need to update the version
GOOS=darwin GOARCH=amd64 go build -ldflags="-s -w" && zip -r9 scc-2.8.0-x86_64-apple-darwin.zip scc
GOOS=darwin GOARCH=386 go build -ldflags="-s -w" && zip -r9 scc-2.8.0-i386-apple-darwin.zip scc
GOOS=windows GOARCH=amd64 go build -ldflags="-s -w" && zip -r9 scc-2.8.0-x86_64-pc-windows.zip scc.exe
GOOS=windows GOARCH=386 go build -ldflags="-s -w" && zip -r9 scc-2.8.0-i386-pc-windows.zip scc.exe
GOOS=linux GOARCH=amd64 go build -ldflags="-s -w" && zip -r9 scc-2.8.0-x86_64-unknown-linux.zip scc
GOOS=linux GOARCH=386 go build -ldflags="-s -w" && zip -r9 scc-2.8.0-i386-unknown-linux.zip scc
Badges (beta)
You can use scc
to provide badges on your github/bitbucket/gitlab open repositories. For example,
The format to do so is,
https://sloc.xyz/PROVIDER/USER/REPO
An example of the badge for scc
is included below, and is used on this page.
[![Scc Count Badge](https://sloc.xyz/github/boyter/scc/)](https://github.com/boyter/scc/)
By default the badge will show the repo's lines count. You can also specify for it to show a different category, by using the ?category=
query string.
Valid values include code, blanks, lines, comments, cocomo
and examples of the appearance are included below.
NB it may not work for VERY large repositories (has been tested on Apache hadoop/spark without issue).
Languages
List of supported languages. The master version of scc
supports 239 languages at last count. Note that this is always assumed that you built from master, and it might trail behind what is actually supported. To see what your version of scc
supports run scc --languages