sh

go-sh

install: go get gomodules.xyz/go-sh

Pipe Example:

package main

import "gomodules.xyz/go-sh"

func main() {
	sh.Command("echo", "hello\tworld").Command("cut", "-f2").Run()
}

Because I like os/exec, go-sh is very much modelled after it. However, go-sh provides a better experience.

These are some of its features:

• keep the variable environment (e.g. export)
• alias support (e.g. alias in shell)
• remember current dir
• pipe command
• shell build-in commands echo & test
• timeout support
• run multiple concurrent leaf commands using a single pipe input

Examples are important:

sh: echo hello
go: sh.Command("echo", "hello").Run()

sh: export BUILD_ID=123
go: s = sh.NewSession().SetEnv("BUILD_ID", "123")

sh: alias ll='ls -l'
go: s = sh.NewSession().Alias('ll', 'ls', '-l')

sh: (cd /; pwd)
go: sh.Command("pwd", sh.Dir("/")).Run()

sh: test -d data || mkdir data
go: if ! sh.Test("dir", "data") { sh.Command("mkdir", "data").Run() }

sh: cat first second | awk '{print $1}'
go: sh.Command("cat", "first", "second").Command("awk", "{print $1}").Run()

sh: count=$(echo "one two three" | wc -w)
go: count, err := sh.Echo("one two three").Command("wc", "-w").Output()

sh(in ubuntu): timeout 1s sleep 3
go: c := sh.Command("sleep", "3"); c.Start(); c.WaitTimeout(time.Second) # default SIGKILL
go: out, err := sh.Command("sleep", "3").SetTimeout(time.Second).Output() # set session timeout and get output)

sh: echo hello | cat
go: out, err := sh.Command("cat").SetInput("hello").Output()

sh: cat # read from stdin
go: out, err := sh.Command("cat").SetStdin(os.Stdin).Output()

sh: ls -l > /tmp/listing.txt # write stdout to file
go: err := sh.Command("ls", "-l").WriteStdout("/tmp/listing.txt")

If you need to keep env and dir, it is better to create a session

session := sh.NewSession()
session.SetEnv("BUILD_ID", "123")
session.SetDir("/")
# then call cmd
session.Command("echo", "hello").Run()
# set ShowCMD to true for easily debug
session.ShowCMD = true

By default, pipeline returns error only if the last command exit with a non-zero status. However, you can also enable pipefail option like bash. In that case, pipeline returns error if any of the commands fail and for multiple failed commands, it returns the error of rightmost failed command.

session := sh.NewSession()
session.PipeFail = true
session.Command("cat", "unknown-file").Command("echo").Run()

By default, pipelines's std-error is set to last command's std-error. However, you can also combine std-errors of all commands into pipeline's std-error using session.PipeStdErrors = true.

By default, pipeline returns error only if the last command exit with a non-zero status. However, you can also enable pipefail option like bash. In that case, pipeline returns error if any of the commands fail and for multiple failed commands, it returns the error of rightmost failed command.

session := sh.NewSession()
session.PipeFail = true
session.Command("cat", "unknown-file").Command("echo").Run()

Designing a Command Chain to Run Multiple Concurrent Leaf Commands Using a Single Pipe Input.

Features be like:

• Input Sharing: All leaf commands take the same input from a pipe.
• Separate Environments: Each leaf command runs with its own environment variables.
• Output Aggregation: Outputs from all commands are combined into a single result.
• Error Handling: Errors are collected and included in the output (e.g., shell or variable).
• Timeouts: Each command has same timeout and will apply simultaneously.

Below is an example of multiple concurrent leaf commands using a single pipe input

s := sh.NewSession()
s.ShowCMD = true
s.Command("echo", "hello world").LeafCommand("xargs").LeafCommand("xargs")
s.Run()

Below is an example of each leaf command runs with its own environment variables

s := sh.NewSession()
s.ShowCMD = true
var args1,args2 []interface{}

mp := make(map[string]string)
mp["COMPANY_NAME"] = "APPSCODE"
args1 = append(args1, "COMPANY_NAME")
args1 = append(args1, mp)
s.LeafCommand("printenv", args1...)

mp["COMPANY_NAME"] = "GOOGLE"
args2 = append(args2, "COMPANY_NAME")
args2 = append(args2, mp)
s.LeafCommand("printenv", args2...)

s.Run()

for more information, it better to see docs.

contribute

If you love this project, starring it will encourage the coder. Pull requests are welcome.

support the author: alipay

thanks

this project is based on http://github.com/codegangsta/inject. thanks for the author.

the reason to use Go shell

Sometimes we need to write shell scripts, but shell scripts are not good at working cross platform, Go, on the other hand, is good at that. Is there a good way to use Go to write shell like scripts? Using go-sh we can do this now.