How to use Regular expression in OOZIE?

Question

I want to check the file exist or not in the given HDFS location.

We can check the file exist or not in given HDFS location with the help of fs:exists i.e.

If file name is test_25082016 with the help of coordination job we can get date value i.e. as a parameter today in our example.

job.prop

path=/user/cloudera/file/input/test_

in workflow.xml

<decision name="CheckFile">
 <switch>
    <case to="nextOozieTask">
      ${fs:exists(concat(concat(nameNode, path),today))}
    </case>
     <case to="nextOozieTask1">
      ${fs:exists(concat(concat(nameNode, path),yesterday))}
    </case>
    <default to="MailActionFileMissing" />
 </switch>  </decision>

it is working as expected.

But in my case i have files names in my HDFS location like below.

Example: test_25082016_08.10.06.681.csv ,test_24082016_08.13.16.681.csv

how to check this types file name i.e. after date values i.e._08.10.06.681.csv ,_08.13.16.681.csv...etc.

Is it possible to use regular expression in oozie workflow, to check those values i.e _08.10.06.681.csv

how to validate in this case file is exist or not through oozie?

please help me on this thanks in advance.

Answer 1

In this case we can check whether the file is exist are not by using below code

<decision name="CheckFile">
 <switch>
    <case to="nextOozieTask">
      ${fs:exists(concat(concat(concat(concat(nameNode, path),today),'*"),'.csv'))}
    </case>
     <case to="nextOozieTask1">
      ${fs:exists(concat(concat(nameNode, path),yesterday))}
    </case>
    <default to="MailActionFileMissing" />
 </switch>  </decision>