29 May 2013

Viewing the contents of an archive

Everyone now and then I want to check the contents of an archive without unpacking it and I tend to use http://linux.about.com/od/commands/l/blcmdl1_unzip.htm to do so:

$ unzip -l batch-import-jar-with-dependencies.jar | tail -n 10
     1645  02-17-13 01:03   org/neo4j/batchimport/StdOutReport.class
     3089  02-17-13 01:03   org/neo4j/batchimport/structs/NodeStruct.class
     1244  02-17-13 01:03   org/neo4j/batchimport/structs/Property.class
     1732  02-17-13 01:03   org/neo4j/batchimport/structs/PropertyHolder.class
     1635  02-17-13 01:03   org/neo4j/batchimport/structs/Relationship.class
      905  02-17-13 01:03   org/neo4j/batchimport/utils/Chunker.class
     1884  02-17-13 01:03   org/neo4j/batchimport/utils/Params.class
     4445  02-17-13 01:03   org/neo4j/batchimport/Utils.class
 --------                   -------
 49947859                   16447 files

It does the job although it does print out some information that we’re not really interested in so I was intrigued to see that Alistair used http://linux.about.com/library/cmd/blcmdl1_zipinfo.htm when he wanted to achieve a similar thing:

$ zipinfo -1 batch-import-jar-with-dependencies.jar | tail -n 10
org/neo4j/batchimport/ParallelImporter.class
org/neo4j/batchimport/Report.class
org/neo4j/batchimport/StdOutReport.class
org/neo4j/batchimport/structs/NodeStruct.class
org/neo4j/batchimport/structs/Property.class
org/neo4j/batchimport/structs/PropertyHolder.class
org/neo4j/batchimport/structs/Relationship.class
org/neo4j/batchimport/utils/Chunker.class
org/neo4j/batchimport/utils/Params.class
org/neo4j/batchimport/Utils.class

From a bit of man page reading it sounds like zipinfo is unzip, but with different flags that give an output that’s a cross between unzip and ls:

The format is a cross between Unix ls -l'' and unzip -v'' output. See DETAILED DESCRIPTION below. Note that zipinfo is the same program as unzip (under Unix, a link to it); on some systems, however, zipinfo support may have been omitted when unzip was compiled.

As long as I remember I’ll be using zipinfo from now on!

About the author

I'm currently working on short form content at ClickHouse. I publish short 5 minute videos showing how to solve data problems on YouTube @LearnDataWithMark. I previously worked on graph analytics at Neo4j, where I also co-authored the O'Reilly Graph Algorithms Book with Amy Hodler.