Update slurm-job-submission-and-execution.md

docs.it4i/general/slurm-job-submission-and-execution.md

@@ -116,13 +116,43 @@ $ cat slurm-1511.out
 
 #### Job Environment Variables
 
-Slurm exposes useful information about job to job main process (usually shell) via environment variables.
-To view all of the Slurm's environment variables, use the command:
+Slurm provides useful information to the job via environment variables. Environment variables are available on all nodes allocated to job when accessed via Slurm supported means (srun, compatible mpirun).
 
-```shell
+See all Slurm variables
+
+```
 set | grep ^SLURM
 ```
 
+### Useful Variables
+
+| variable name | description | example |
+| ------ | ------ | ------ |
+| SLURM_JOBID | job id of the executing job| 593 |
+| SLURM_JOB_NODELIST | nodes allocated to the job | p03-amd[01-02] |
+| SLURM_JOB_NUM_NODES | number of nodes allocated to the job | 2 |
+| SLURM_STEP_NODELIST | nodes allocated to the job step | p03-amd01 |
+| SLURM_STEP_NUM_NODES | number of nodes allocated to the job step | 1 |
+| SLURM_JOB_PARTITION | name of the partition | p03-amd |
+| SLURM_SUBMIT_DIR | submit directory | /scratch/project/open-xx-yy/work |
+
+See [Slurm srun documentation][2] for details.
+
+Get job nodelist
+
+```
+$ echo $SLURM_JOB_NODELIST
+cn[10-11]
+```
+
+Expand nodelist to list of nodes.
+
+```
+$ scontrol show hostnames $SLURM_JOB_NODELIST
+cn10
+cn11
+```
+
 #### Common Job Workflow
 
 !!! Note