go-process/program.go
Virgil cdc8bfe502 feat(process): add readiness accessors and AX examples
Co-Authored-By: Virgil <virgil@lethean.io>
2026-04-04 00:39:27 +00:00

100 lines
2.9 KiB
Go

package process
import (
"bytes"
"context"
"fmt"
"os/exec"
"strings"
coreerr "dappco.re/go/core/log"
)
// ErrProgramNotFound is returned when Find cannot locate the binary on PATH.
// Callers may use errors.Is to detect this condition.
var ErrProgramNotFound = coreerr.E("", "program: binary not found in PATH", nil)
// ErrProgramContextRequired is returned when Run or RunDir is called without a context.
var ErrProgramContextRequired = coreerr.E("", "program: command context is required", nil)
// ErrProgramNameRequired is returned when Run or RunDir is called without a program name.
var ErrProgramNameRequired = coreerr.E("", "program: program name is empty", nil)
// Program represents a named executable located on the system PATH.
//
// Example:
//
// git := &process.Program{Name: "git"}
// if err := git.Find(); err != nil { return err }
// out, err := git.Run(ctx, "status")
type Program struct {
// Name is the binary name (e.g. "go", "node", "git").
Name string
// Path is the absolute path resolved by Find.
// Example: "/usr/bin/git"
// If empty, Run and RunDir fall back to Name for OS PATH resolution.
Path string
}
// Find resolves the program's absolute path using exec.LookPath.
// Returns ErrProgramNotFound (wrapped) if the binary is not on PATH.
//
// Example:
//
// if err := p.Find(); err != nil { return err }
func (p *Program) Find() error {
if p.Name == "" {
return coreerr.E("Program.Find", "program name is empty", nil)
}
path, err := exec.LookPath(p.Name)
if err != nil {
return coreerr.E("Program.Find", fmt.Sprintf("%q: not found in PATH", p.Name), ErrProgramNotFound)
}
p.Path = path
return nil
}
// Run executes the program with args in the current working directory.
// Returns trimmed combined stdout+stderr output and any error.
//
// Example:
//
// out, err := p.Run(ctx, "hello")
func (p *Program) Run(ctx context.Context, args ...string) (string, error) {
return p.RunDir(ctx, "", args...)
}
// RunDir executes the program with args in dir.
// Returns trimmed combined stdout+stderr output and any error.
// If dir is empty, the process inherits the caller's working directory.
//
// Example:
//
// out, err := p.RunDir(ctx, "/tmp", "pwd")
func (p *Program) RunDir(ctx context.Context, dir string, args ...string) (string, error) {
if ctx == nil {
return "", coreerr.E("Program.RunDir", "program: command context is required", ErrProgramContextRequired)
}
binary := p.Path
if binary == "" {
binary = p.Name
}
if binary == "" {
return "", coreerr.E("Program.RunDir", "program name is empty", ErrProgramNameRequired)
}
var out bytes.Buffer
cmd := exec.CommandContext(ctx, binary, args...)
cmd.Stdout = &out
cmd.Stderr = &out
if dir != "" {
cmd.Dir = dir
}
if err := cmd.Run(); err != nil {
return strings.TrimSpace(out.String()), coreerr.E("Program.RunDir", fmt.Sprintf("%q: command failed", p.Name), err)
}
return strings.TrimSpace(out.String()), nil
}