Executing a Bash Script from Golang

Question

I am trying to figure out a way to execute a script (.sh) file from Golang. I have found a couple of easy ways to execute commands (e.g. os/exec), but what I am looking to do is to execute an entire sh file (the file sets variables etc.).

Using the standard os/exec method for this does not seem to be straightforward: both trying to input "./script.sh" and loading the content of the script into a string do not work as arguments for the exec function.

for example, this is an sh file that I want to execute from Go:

OIFS=$IFS; IFS=",";  # fill in your details here dbname=testDB host=localhost:27017 collection=testCollection exportTo=../csv/  # get comma separated list of keys. do this by peeking into the first document in the collection and get his set of keys keys=`mongo "$host/$dbname" --eval "rs.slaveOk();var keys = []; for(var key in db.$collection.find().sort({_id: -1}).limit(1)[0]) { keys.push(key); }; keys;" --quiet`; # now use mongoexport with the set of keys to export the collection to csv mongoexport --host $host -d $dbname -c $collection --fields "$keys" --csv --out $exportTo$dbname.$collection.csv;  IFS=$OIFS; 

from the Go program:

out, err := exec.Command(mongoToCsvSH).Output()     if err != nil {         log.Fatal(err)     }     fmt.Printf("output is %s\n", out) 

where mongoToCsvSH can be either the path to the sh or the actual content - both do not work.

Any ideas how to achieve this?

Answer 1

For your shell script to be directly runnable you have to:

1. Start it with #!/bin/sh (or #!/bin/bash, etc).

2. You have to make it executable, aka chmod +x script.

If you don't want to do that, then you will have to execute /bin/sh with the path to the script.

cmd := exec.Command("/bin/sh", mongoToCsvSH) 

Answer 2

This worked for me

func Native() string {     cmd, err := exec.Command("/bin/sh", "/path/to/file.sh").Output()     if err != nil {     fmt.Printf("error %s", err)     }     output := string(cmd)     return output }