bash使用sed从变量添加字符串

Question

I need to edit a files using shell script (sed), I can't seem to get it to work when I use "space" inside my string.

This is the bash script:

##Edit instancegroup files with relevant cluster
CLUSTER_NAME=clusters.dev10.k8s.local
oldcluster="kops.k8s.io/cluster:"
newcluster="kops.k8s.io/cluster: ${CLUSTER_NAME}"
sed -i 's@'${oldcluster}'@'${newcluster}'@g' myfile

This is myfile :

apiVersion: kops/v1alpha2
kind: InstanceGroup
metadata:
  creationTimestamp: 2018-01-03T10:45:43Z
  labels:
    kops.k8s.io/cluster:

And this is the error I get:

administrator@JenkisSrv01:~/awscluster/instancegroup$ ./try.sh
sed: -e expression #1, char 43: unterminated `s' command

When I removing the space from line 4, it is working well:

newcluster="kops.k8s.io/cluster:${CLUSTER_NAME}"

Answer 1

Unquoted space separates parameters. Quote the variable:

sed -i 's@'"${oldcluster}"'@'"${newcluster}"'@g' myfile

or more readably

sed -i "s@$oldcluster@$newcluster@g" myfile

Note that . has a special meaning in regexes, so kops.k8s.io/cluster: matches eg kopsXk8sXio/cluster: . You need to backslash the dots to force the literal meaning.

Answer 2

在变量周围添加双引号

sed -i 's@'"${oldcluster}"'@'"${newcluster}"'@g' myfile