title: Parse file and store string after match in variable for each line
body: <p>I have file a.txt</p>
  
  <pre><code>GOARCH="amd64"
  GOBIN=""
  GOEXE=""
  GOHOSTARCH="amd64"
  GOHOSTOS="linux"
  GOOS="linux"
  GOPATH="/go"
  GORACE=""
  GOROOT="/usr/local/go"
  GOTOOLDIR="/usr/local/go/pkg/tool/linux_amd64"
  GO15VENDOREXPERIMENT="1"
  CC="gcc"
  GOGCCFLAGS="-fPIC -m64 -pthread -fmessage-length=0"
  CXX="g++"
  CGO_ENABLED="1"
  </code></pre>
  
  <p>How to parse every line in this file to get values after <code>=</code>, ie, get values after</p>
  
  <pre><code>GOARCH=
  GOBIN=
  GOEXE=
  GOHOSTARCH=
  GOHOSTOS=
  GOOS=
  GOPATH=
  GORACE=
  GOROOT=
  GOTOOLDIR=
  GO15VENDOREXPERIMENT=
  CC=
  GOGCCFLAGS=
  CXX=
  CGO_ENABLED=
  </code></pre>
  
  <p>and store each line in separate variable</p>
  
  <p>for example, for first line</p>
  
  <pre><code>echo $goarch
  amd64
  </code></pre>
  
  <p>second line</p>
  
  <pre><code>echo $gobin
  </code></pre>
  
  <p>and so on</p>