How to use the child_process.exec.bind function in child_process

function git(text, opts) {
    return exec.bind(null, 'git ' + text, opts);
}

var exec = require('child_process').exec

var opts = {
  cwd: __dirname
}

module.exports = {
  start: exec.bind(null, './start.sh', opts),
  stop: exec.bind(null, './stop.sh', opts),
  uri: 'http://localhost:' + (process.env.TRAVIS === 'true' ? 5984 : 15986) + '/registry/_design/app/_rewrite/'
}

var exec = require('child_process').exec

var opts = {
  cwd: __dirname
}

module.exports = {
  start: exec.bind(null, './start.sh', opts),
  stop: exec.bind(null, './stop.sh', opts),
  uri: 'http://localhost:' + (process.env.TRAVIS === 'true' ? 5984 : 15986) + '/registry/_design/app/_rewrite/'
}

parseImports(full_path, true, (err, srcs) => {
        if (err) return reject(err)
        cache.setWxssMap(srcs)
        let execWcsc = execFile.bind(null, wcsc, wxss_args.concat(srcs))
        if (isLinux) {
          execWcsc = exec.bind(null, [wcsc].concat(wxss_args).concat(srcs).join(' '))
        }
        execWcsc({maxBuffer: 1024 * 600}, (err, stdout, stderr) => {
          if (err) {
            console.error(err.stack)
            return reject(new Error(`${full_path} 编译失败，请检查`))
          }
          if (stderr) return reject(new Error(stderr))
          wxssSourcemap(full_path, stdout).then(content => {
            cache[full_path] = content
            resolve(content)
          }, reject)
        })
      })
    } else if (/\.js$/.test(full_path)) {

parseImports(fullPath, false, (err, srcs) => {
        if (err) return reject(err)

        const wxmlCmpRes = wxmlTranspiler.wxmlCompile(srcs)
        const tagsInCode = wxmlCmpRes.tags
        if (useDefaultCompiler) {
          let execWcc = execFile.bind(null, wcc, wxmlArgs.concat(srcs))
          if (isLinux) {
            execWcc = exec.bind(
              null,
              [wcc]
                .concat(wxmlArgs)
                .concat(srcs)
                .join(' ')
            )
          }
          if (wxmlMsgFlag) {
            console.log(chalk.yellow('Using wcc.exe to transpile wxml:'))
            wxmlMsgFlag = 0
          }
          execWcc({ maxBuffer: 1024 * 600 }, (err, stdout, stderr) => {
            if (err) {
              console.error(err.stack)
              return reject(new Error(`${fullPath} 编译失败，请检查`))
            }

], function() {
        
        var updateSprite = exec.bind(undefined, 'audiosprite --format howler --path build/ --output ui/public/build/sprite --export mp3 ui/public/sounds/*.mp3 ui/public/sounds/*.wav', cb);
        
        if(downloads.length > 0) {
            return es.merge.apply(undefined, downloads).on('end', function() {
                updateSprite();
            });
        }
        
        updateSprite();
        
    });