Merge pull request #99 from xushiwei/log

x/gsh

gsh/README.md

@@ -0,0 +1,135 @@
+Go+ DevOps Tools
+======
+
+[![Language](https://img.shields.io/badge/language-Go+-blue.svg)](https://github.com/goplus/gop)
+[![GitHub release](https://img.shields.io/github/v/tag/goplus/gop.svg?label=Go%2b+release)](https://github.com/goplus/gop/releases)
+[![Discord](https://img.shields.io/badge/Discord-online-success.svg?logo=discord&logoColor=white)](https://discord.gg/mYjWCJDcAr)
+[![GoDoc](https://pkg.go.dev/badge/github.com/qiniu/x/gsh.svg)](https://pkg.go.dev/github.com/qiniu/x/gsh)
+
+This is an alternative to writing shell scripts.
+
+Yes, now you can write `shell script` in Go+. It supports all shell commands.
+
+## Usage
+
+First, let's create a Go+ source file named `./example.gsh` and write the following code:
+
+```coffee
+mkdir "testgsh"
+```
+
+Then run it:
+
+```sh
+gop run example.gsh
+```
+
+It's strange to you that the file extension of Go+ source is not `.gop` but `.gsh`. It is only because Go+ register `.gsh` as a builtin [classfile](https://github.com/goplus/gop/blob/main/doc/classfile.md).
+
+We can change `./example.gsh` more complicated:
+
+```coffee
+type file struct {
+	name  string
+	fsize int
+}
+
+mkdir! "testgsh"
+
+mkdir "testgsh2"
+lastErr!
+
+mkdir "testgsh3"
+if lastErr != nil {
+	panic lastErr
+}
+
+capout => { ls }
+println output.fields
+
+capout => { ls "-l" }
+files := [file{flds[8], flds[4].int!} for e <- output.split("\n") if flds := e.fields; flds.len > 2]
+println files
+
+rmdir "testgsh", "testgsh2", "testgsh3"
+```
+
+### Check last error
+
+If we want to ensure `mkdir` successfully, there are three ways:
+
+The simplest way is:
+
+```coffee
+mkdir! "testsh"  # will panic if mkdir failed
+```
+
+The second way is:
+
+```coffee
+mkdir "testsh"
+lastErr!
+```
+
+Yes, `gsh` provides `lastErr` to check last error.
+
+The third way is:
+
+```coffee
+mkdir "testsh"
+if lastErr != nil {
+    panic lastErr
+}
+```
+
+This is the most familiar way to Go developers.
+
+### Capture output of commands
+
+And, `gsh` provides a way to capture output of commands:
+
+```coffee
+capout => {
+    ...
+}
+```
+
+Similar to `lastErr`, the captured output result is saved to `output`.
+
+For an example:
+
+```coffee
+capout => { ls "-l" }
+println output
+```
+
+Here is a possible output:
+
+```s
+total 72
+-rw-r--r--  1 xushiwei  staff  11357 Jun 19 00:20 LICENSE
+-rw-r--r--  1 xushiwei  staff    127 Jun 19 10:00 README.md
+-rw-r--r--  1 xushiwei  staff    365 Jun 19 00:25 example.gsh
+-rw-r--r--  1 xushiwei  staff    126 Jun 19 09:33 go.mod
+-rw-r--r--  1 xushiwei  staff    165 Jun 19 09:33 go.sum
+-rw-r--r--  1 xushiwei  staff   1938 Jun 19 10:00 gop_autogen.go
+```
+
+We can use [Go+ powerful built-in data processing capabilities](doc/docs.md#data-processing) to process captured `output`:
+
+```coffee
+type file struct {
+	name  string
+	fsize int
+}
+
+files := [file{flds[8], flds[4].int!} for e <- output.split("\n") if flds := e.fields; flds.len > 2]
+```
+
+In this example, we split `output` by `"\n"`, and for each entry `e`, split it by spaces (`e.fields`) and save into `flds`. Condition `flds.len > 2` is to remove special line of output:
+
+```s
+total 72
+```
+
+At last, pick file name and size of all selected entries and save into `files`.

gsh/classfile.go

@@ -0,0 +1,78 @@
+/*
+ Copyright 2024 Qiniu Limited (qiniu.com)
+
+ Licensed under the Apache License, Version 2.0 (the "License");
+ you may not use this file except in compliance with the License.
+ You may obtain a copy of the License at
+
+     http://www.apache.org/licenses/LICENSE-2.0
+
+ Unless required by applicable law or agreed to in writing, software
+ distributed under the License is distributed on an "AS IS" BASIS,
+ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ See the License for the specific language governing permissions and
+ limitations under the License.
+*/
+
+package gsh
+
+import (
+	"bytes"
+	"io"
+	"os"
+	"os/exec"
+)
+
+// App is project class of this classfile.
+type App struct {
+	fout io.Writer
+	ferr io.Writer
+	fin  io.Reader
+	cout string
+	err  error
+}
+
+func (p *App) initApp() {
+	p.fin = os.Stdin
+	p.fout = os.Stdout
+	p.ferr = os.Stderr
+}
+
+// Gop_Exec executes a shell command.
+func (p *App) Gop_Exec(name string, args ...string) error {
+	cmd := exec.Command(name, args...)
+	cmd.Stdin = p.fin
+	cmd.Stdout = p.fout
+	cmd.Stderr = p.ferr
+	p.err = cmd.Run()
+	return p.err
+}
+
+// LastErr returns error of last command execution.
+func (p *App) LastErr() error {
+	return p.err
+}
+
+// Capout captures stdout of doSth() execution and save it to output.
+func (p *App) Capout(doSth func()) (string, error) {
+	var out bytes.Buffer
+	old := p.fout
+	p.fout = &out
+	defer func() {
+		p.fout = old
+	}()
+	doSth()
+	p.cout = out.String()
+	return p.cout, p.err
+}
+
+// Output returns result of last capout.
+func (p *App) Output() string {
+	return p.cout
+}
+
+// Gopt_App_Main is main entry of this classfile.
+func Gopt_App_Main(a interface{ initApp() }) {
+	a.initApp()
+	a.(interface{ MainEntry() }).MainEntry()
+}