HDFS File Existence Check: Understanding and Using Shell Return Codes ($?)

[#1]

Hi, I am performing a basic check to see if a file exists in HDFS or not. I am using hdfs dos -test command for the same. But it doesn't seem to work correctly. In the documentation its mentioned as it would return 0 if the file exists. But I am not getting any output when the command is run. Let me know what need to be done to get this working. Please see the screenshot attached Thanks

[#2 · Accepted solution]

@bigdata.neophyte The hdfs command doesn't print the result but sets it's return code to the shell. You'll need to test the return code from the 'hdfs dfs -test' command. On Linux try this:

hdfs dfs -test -e /tmp
echo $?
hdfs dfs -test -e /this_doesnt_exist
echo $?

[#3]

Thanks @Terry Stebbens

[#4]

@bigdata.neophyte Here is the usage -

Usage: hadoop fs -test -[defsz] URI

Options:

• -d: f the path is a directory, return 0.
• -e: if the path exists, return 0.
• -f: if the path is a file, return 0.
• -s: if the path is not empty, return 0.
• -z: if the file is zero length, return 0.

Example:

• hadoop fs -test -e filename

Check - http://hadoop.apache.org/docs/current/hadoop-project-dist/hadoop-common/FileSystemShell.html#test

[#5]

Hi Team , Is there any way to test multiple files exist or not in single command?? like below.. pls suggest

• hadoop fs -test -e filename1 filename2