Running JAVA in Cygwin through bash script

Question

I've been encountering a problem with cygwin where I cannot run a jar file with an error that the file cannot be found.

If it were easier i would "translate" the java source in bash, but unfortunately, due to the functionality implemented, there are some quite significant obstacles to achieve this, so I'd have to use the jar file.

Now, I've done a fair amount of research on my part to figure out how to do this, however, I couldn't succeed, and it is mandatory that i use cygwin.

Here's what I'm trying to essentially do:

lockfile="$specialfolder/$passedargument.lock
java -jar `cygpath -w ./cygdrive/driveletter/folder/folder/javafile.jar -joption cygpath -w $lockfile`

i also tried with double back-ticks, as follows:

pathtooutfile="${some_other_vars}/${that}_${work}.out"
java -jar `cygpath -w ./cygdrive/driveletter/folder/folder/javafile.jar` -joption `cygpath -w $lockfile`

i also tried using the $JAVA_HOME env var but that did not work as well. It is important to mention that the variables being called in lockfile var are defined as follows:

 homedir= "/cygdrive/driveletter/folder/folder"
 specialfolder= "$homedir/foler/$passedargument"
 passedargument= $1 ###argument passed with execution of bash script
 lockfile= "$specialfolder/$passedargument"

The error i keep getting is this: Error: Unable to access jarfile I have modified usage rights to 777 and that didn't work either. It might also be important to mention that -joption is either -aquire or -release corresponding to the lockfile since one of the things the jar does is manage multiple script executions through a lock file. I'm somewhat stuck so, any suggestions will be greatly appreciated. I think that this might be more of a cygwin issue.

Answer 1

Have you tried cygpath -w -a .....

The -a returns absolute paths.

e.g.

$ cygpath -w ./screenshot.jpg
screenshot.jpg

$ cygpath -w -a ./screenshot.jpg
C:\cygwin64\home\tony\screenshot.jpg

Answer 2

If your expression

`cygpath -w ./cygdrive/driveletter/folder/folder/javafile.jar`

has embedded blanks, you should put double-quotes around it so that the result is passed to Java as a single token. It can help to understand the expressions and results if you turn on the shell trace, e.g., set -x.

Further reading:

• cygpath — Convert Unix and Windows format paths, or output system path information
• Making Cygwin and Windows cooperate

Answer 3

Windows absolute paths always start with a drive letter, for example C:\folder1\folder2\item.ext. Cygwin absolute paths start with / - just like all UNIX/Linux filesystems - but provide a metafolder cygdrive that allows disparate Windows drive letters to be mapped seamlessly into the one filesystem tree, for example /cygdrive/c/folder1/folder2/item.ext. (In fact the two example file paths I've given would correspond to the same filesystem object.)

The fundamental problem here is that you have an invalid path. It's a relative path because it doesn't begin with /, but then it references what looks like an absolute path corresponding to a Windows drive letter and path:

cygpath -w ./cygdrive/driveletter/folder/folder/javafile.jar

What I think you probably meant was this, without the leading dot:

cygpath -w /cygdrive/driveletter/folder/folder/javafile.jar

Fixing the quoting and generally tidying up, that would make your script segment look like this:

lockfile="$specialfolder/$passedargument.lock"
java -jar "$(cygpath -w /cygdrive/driveletter/folder/folder/javafile.jar)" -joption "$(cygpath -w "$lockfile")"