Mryntu

So I have written a bash script which create series of directories and clone a project to selected directories. But for that I need to cd to each directory (project 1 and project 2) but script doesn't cd to the second directory and execute the command. Instead, it stops after cd and cloning in theproject2 directory. Why it doesn't call the cd_project1 function in following code?

 #!/bin/bash
 #Get the current user name 

 function my_user_name() 
 current_user=$USER
 echo " Current user is $current_user"
 

 #Creating useful directories

 function create_useful_directories() 
 if [[ ! -d "$scratch" ]]; then
 echo "creating relevant directory"
 mkdir -p /home/"$current_user"/Downloads/scratch/"$current_user"/project1/project2
 else
 echo "scratch directory already exists"
 :
 fi
 

#Going to project2 and cloning 

 function cd_project2() 

 cd /home/"$current_user"/Downloads/scratch/"$current_user"/project1/project2 &&
 git clone https://username@bitbucket.org/teamsinspace/documentation-tests.git
 exec bash
 

#Going to project1 directory and cloning 
 function cd_project1() 

 cd /home/"$current_user"/Downloads/scratch/"$current_user"/project1/ &&
 git clone https://username@bitbucket.org/teamsinspace/documentation-tests.git
 exec bash

 

 #Running the functions 
 function main() 

 my_user_name
 create_useful_directories
 cd_project2
 cd_project1 
 
 main

 #Terminal output 
 ~/Downloads$. ./bash_install_script.sh 
 Current user is mihi
 creating relevant directory
 Cloning into 'documentation-tests'...
 remote: Counting objects: 125, done.
 remote: Compressing objects: 100% (115/115), done.
 remote: Total 125 (delta 59), reused 0 (delta 0)
 Receiving objects: 100% (125/125), 33.61 KiB | 362.00 KiB/s, done.
 Resolving deltas: 100% (59/59), done.
 ~/Downloads/scratch/mihi/project1/project2$

The culprits are your exec bash statements in some of your functions.
The exec statement is a bit weird and not easily understood in the first place.
It means: execute the following command instead of the currently running
command/shell/script from here on. That is: it replaces the current shell
script (in your case) with an instance of bash and it never returns.

You can try this out with a shell and issue

exec sleep 5

This will replace your current shell (the bash) with the command sleep 5
and when that command returns (after 5 seconds) your window will close because
the shell has been replaced with sleep 5.

Same with your script: If you put exec something into your script, the script
gets replaced with something and when that something stops execution, the
whole script stops.

Simply dropping the exec bash statements should do.

From help exec:

exec: exec [-cl] [-a name] [command [arguments ...]] [redirection ...]
 Replace the shell with the given command.

 Execute COMMAND, replacing this shell with the specified program.
 ARGUMENTS become the arguments to COMMAND. If COMMAND is not specified,
 any redirections take effect in the current shell.

The key word here is replace - if you exec bash from inside a script, no further script execution can occur.