README
¶
go-caller
A lightweight and idiomatic Go library that captures and formats caller information such as file name, line number, function name, and package path.
Perfect for use in:
- Custom error types
- Logging wrappers
- Debugging utilities
- Tracing and instrumentation
✨ Features
- Minimal and dependency-free
- Clean, consistent API with platform-independent file paths
- Get full or short location (
file:line) - Extract function name, full function path, and package info
- Implements
fmt.Stringerinterface for easy logging - Implements
json.Marshalerandjson.Unmarshalerinterfaces for easy JSON serialization - Implements
slog.LogValuerinterface for structured logging
🚀 Usage
import "github.com/balinomad/go-caller"
func someFunc() {
c := caller.Immediate()
fmt.Println("Caller location:", c.Location())
fmt.Println("Short:", c.ShortLocation())
fmt.Println("Function:", c.Function())
fmt.Println("Package:", c.PackageName())
data, err := json.Marshal(c)
if err != nil {
log.Fatal(err)
}
fmt.Println("JSON:", string(data))
}
📌 Installation
go get github.com/balinomad/go-caller@latest
📘 API Highlights
| Method | Description |
|---|---|
File() |
Full file path |
Line() |
Line number |
Location() |
Full location (path/to/file.go:123) |
ShortLocation() |
Short location (file.go:123) |
Function() |
Method/function name only |
FullFunction() |
Full path to method including package |
Package() |
Full import path of the package |
PackageName() |
Last element of the package path |
String() |
Returns ShortLocation() for easy logging |
MarshalJSON() |
Marshal caller info to JSON |
UnmarshalJSON() |
Unmarshal JSON to caller info |
LogValue() |
Construct a slog.Value for structured logging |
🔧 Advanced
For custom skipping depth or use with program counters:
c := caller.New(skip)
c := caller.NewFromPC(pc)
⚖️ License
MIT License — see LICENSE file for details.
Documentation
¶
Overview ¶
Package caller provides utilities to extract source code location information (file, line, function, and package) for the current or specified call frame. It is designed for use in logging, error reporting, and debugging with a lightweight and idiomatic API. Caller captures runtime metadata using the Go runtime and formats it in a developer-friendly way.
Example usage:
import "github.com/balinomad/go-caller"
func someFunc() {
c := caller.Immediate()
fmt.Println("Caller location:", c.Location())
fmt.Println("Short:", c.ShortLocation())
fmt.Println("Function:", c.Function())
fmt.Println("Package:", c.PackageName())
data, err := json.Marshal(c)
if err != nil {
log.Fatal(err)
}
fmt.Println("JSON:", string(data))
}
Index ¶
Constants ¶
This section is empty.
Variables ¶
This section is empty.
Functions ¶
This section is empty.
Types ¶
type Caller ¶
type Caller interface {
fmt.Stringer
json.Marshaler
json.Unmarshaler
slog.LogValuer
// Valid returns true if the caller is usable.
Valid() bool
// File returns the file name.
File() string
// Line returns the line number.
Line() int
// Location returns a formatted string with file:line.
Location() string
// ShortLocation returns a formatted string with just filename:line.
ShortLocation() string
// Function returns just the function or method name
// without package prefix.
Function() string
// FullFunction returns the full function name including package.
FullFunction() string
// Package returns the full import path of the function.
Package() string
// PackageName returns the name of the package without the directory.
PackageName() string
}
Caller provides access to source information about the caller.
func Immediate ¶
func Immediate() Caller
Immediate returns a Caller for the immediate caller of the function that calls Immediate(). Returns nil if the caller cannot be determined.
Source Files