I used the SortSam option with GATK4 picard tools but it gives an error saying: htsjdk.samtools.util.RuntimeIOException: Problem writing temporary file file:///tmp/xxxxxx//sortingcollection.1885090825398510531.tmp.  Try setting TMP_DIR to a file system with lots of space

I referred to this (https://www.biostars.org/p/42613/) post with the following command:

    java -Xmx2g -Djava.io.tmpdir=`pwd`/tmp -jar SortSam.jar SORT_ORDER=coordinate INPUT=input.bam OUTPUT=output.sort TMP_DIR=`pwd`/tmp

However, I run GATK directly from the Linux terminal with the command:

    ./gatk SortSam
Also, there is no SortSam.jar file in the directory. Only a gatk-package-4.0.11.0-local.jar.

How do I modify the syntax of the above command to set the temporary directory ? 

I got it using  

     ./gatk --java-options "-Djava.io.tmpdir=/custom file path" SortSam -I=samplealn.sam -O=sortedsamplealn.bam -SO=coordinate --TMP_DIR=/custom file path

