Explain Strange Behavior

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In my bin directory, most of the binaries are linked to it. It is in my path. I have googled this and cannot find anything close.

I am running bash on CentOS6.8

When I run “which command” most of the files in this custom bin directory show up.

When I run “which file.jar” it cannot see it, but I can *ls* the file
(soft link)

as which only works on executables (according to man page), I created a dan.jar empty file and did a which on dan.tar and found it.

can anyone explain what is happening and how I can soft link the jar files to my bin directory so which can see them?

Dan

3 thoughts on - Explain Strange Behavior

  • `which` will only show files that have chmod +x set and are in the path.

    jar files aren’t directly executable by the shell, you have to run java
    -jar name.jar to execute them, so there’s no point in having them in the path or +x.

  • Do these files that are not shown by which command have “execute” bit on for everyboty (in other words, can regular user executing the command
    “which” execute that file, and read that file: what is set in UNIX
    permissions for that file.

    Showing us what

    ls -l /usr/local/bin/file.jar

    (if it is symlink, show us permission of actual file symlink points to)

    Valeri

    ++++++++++++++++++++++++++++++++++++++++
    Valeri Galtsev Sr System Administrator Department of Astronomy and Astrophysics Kavli Institute for Cosmological Physics University of Chicago Phone: 773-702-4247
    ++++++++++++++++++++++++++++++++++++++++

  • I don’t use java, so this may be way off base.

    I’m assuming you have several *.jar files, but will work with two, foo.jar and bar.jar.

    Place all your jar files in a single directory, not bin. Under lib is the common place. I’ll use /home/dan/lib/jarfiles.

    In your bin directory place a shell script named “foo” containing something like this:

    #!/usr/bin/bash

    ProgName=${0##*/} # (basename) strips dirs from path
    JarDir=/home/dan/lib/jarfiles
    JarFile=${JarDir}/${ProgName}.jar

    ## possibly test for existance of jar file

    java -jar ${JarFile} “${@}” # I assume there may be args to pass.

    That would let you run foo.jar as “foo” and do a “which foo” as it is an executable shell script.

    For bar.jar you merely need to put it in the JarDir and make a link in the bin directory:

    ln /home/dan/bin/foo /home/dan/bin/bar

    Do the same for each *.jar, move to JarDir, make a link.

    If particular jar files need special treatment you can put a switch statement in the script based on $ProgName.

    Jon

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