go get -u github.com/ofabry/go-callvis
# or
git clone https://github.com/ofabry/go-callvis.git
cd go-callvis && make install

package main

import (
    
    func main() {
        // Part 1: create a listener
        l, err := net.Listen("tcp", ":8000")
        if err != nil {
            log.Fatalf("Error listener returned: %s", err)
        }
        defer l.Close()
        
        for {
            // Part 2: accept new connection
            c, err := l.Accept()
            if err != nil {
                log.Fatalf("Error to accept new connection: %s", err)
            }
            
            // Part 3: create a goroutine that reads and write back data
            go func() {
                log.Printf("TCP session open")
                defer c.Close()
                
                for {
                    d := make([]byte, 1024)
                    
                    // Read from TCP buffer
                    _, err := c.Read(d)
                    if err != nil {
                        log.Printf("Error reading TCP session: %s", err)
                        break
                    }
                    log.Printf("reading data from client: %s\n", string(d))
                    
                    // write back data to TCP client
                    _, err = c.Write(d)
                    if err != nil {
                        log.Printf("Error writing TCP session: %s", err)
                        break
                    }
                }
            }()
        }
}

$ go-callvis main.go
2022/08/14 21:23:03 http serving at http://localhost:7878
2022/08/14 21:23:03 converting dot to svg..
2022/08/14 21:23:03 serving file: /var/folders/xk/gn46n46d503dsztbc6_9qb2h0000gn/T/go-callvis_export.svg

go-callvis [flags] package

go-callvis -tests yourpackage

$ go-callvis
go-callvis: visualize call graph of a Go program.

Usage:

go-callvis [flags] package

Package should be main package, otherwise -tests flag must be used.

Flags:

-algo string
The algorithm used to construct the call graph. Possible values inlcude: "static", "cha", "rta", "pointer" (default "pointer")
-cacheDir string
Enable caching to avoid unnecessary re-rendering, you can force rendering by adding 'refresh=true' to the URL query or emptying the cache directory
-debug
Enable verbose log.
-file string
output filename - omit to use server mode
-focus string
Focus specific package using name or import path. (default "main")
-format string
output file format [svg | png | jpg | ...] (default "svg")
-graphviz
Use Graphviz's dot program to render images.
-group string
Grouping functions by packages and/or types [pkg, type] (separated by comma) (default "pkg")
-http string
HTTP service address. (default ":7878")
-ignore string
Ignore package paths containing given prefixes (separated by comma)
-include string
Include package paths with given prefixes (separated by comma)
-limit string
Limit package paths to given prefixes (separated by comma)
-minlen uint
Minimum edge length (for wider output). (default 2)
-nodesep float
Minimum space between two adjacent nodes in the same rank (for taller output). (default 0.35)
-nodeshape string
graph node shape (see graphvis manpage for valid values) (default "box")
-nodestyle string
graph node style (see graphvis manpage for valid values) (default "filled,rounded")
-nointer
Omit calls to unexported functions.
-nostd
Omit calls to/from packages in standard library.
-rankdir string
Direction of graph layout [LR | RL | TB | BT] (default "LR")
-skipbrowser
Skip opening browser.
-tags build tags
a list of build tags to consider satisfied during the build. For more information about build tags, see the description of build constraints in the documentation for the go/build package
-tests
Include test code.
-version
Show version and exit.
[slp@slpdeMacBook-Pro:] ~/repo/MongoShake/cmd/collector $ go-callvis --help
Usage of go-callvis:
-algo string
The algorithm used to construct the call graph. Possible values inlcude: "static", "cha", "rta", "pointer" (default "pointer")
-cacheDir string
Enable caching to avoid unnecessary re-rendering, you can force rendering by adding 'refresh=true' to the URL query or emptying the cache directory
-debug
Enable verbose log.
-file string
output filename - omit to use server mode
-focus string
Focus specific package using name or import path. (default "main")
-format string
output file format [svg | png | jpg | ...] (default "svg")
-graphviz
Use Graphviz's dot program to render images.
-group string
Grouping functions by packages and/or types [pkg, type] (separated by comma) (default "pkg")
-http string
HTTP service address. (default ":7878")
-ignore string
Ignore package paths containing given prefixes (separated by comma)
-include string
Include package paths with given prefixes (separated by comma)
-limit string
Limit package paths to given prefixes (separated by comma)
-minlen uint
Minimum edge length (for wider output). (default 2)
-nodesep float
Minimum space between two adjacent nodes in the same rank (for taller output). (default 0.35)
-nodeshape string
graph node shape (see graphvis manpage for valid values) (default "box")
-nodestyle string
graph node style (see graphvis manpage for valid values) (default "filled,rounded")
-nointer
Omit calls to unexported functions.
-nostd
Omit calls to/from packages in standard library.
-rankdir string
Direction of graph layout [LR | RL | TB | BT] (default "LR")
-skipbrowser
Skip opening browser.
-tags build tags
a list of build tags to consider satisfied during the build. For more information about build tags, see the description of build constraints in the documentation for the go/build package
-tests
Include test code.
-version
     Show version and exit.