Update file UNIX_HPC_exercise_instructions.md

exercises/UNIX_HPC_exercise_instructions.md

@@ -343,7 +343,7 @@
 
 3. Writing a simple script that copies and renames files:
    ```sh
-   #!/bin/bash
+   #!/usr/bin/env bash
    for x in ompA*.fasta
    do
       # save file ending in variable
@@ -357,7 +357,7 @@
 4. To make it more reusable, you can use additional variables whose values can be easily changed and adapted to new use cases.   
 
    ```sh
-   #!/bin/bash
+   #!/usr/bin/env bash
 
    # Define variables prior to your actual code and use these throughout instead of hard-coded names
    name1="ompA"
@@ -401,7 +401,7 @@
 6. Modifying the script further to use arrays:
 
    ```sh
-   #!/bin/bash
+   #!/usr/bin/env bash
 
    name1="ompA"
    name2="outerMembraneProteinA"