Yes, No, Maybe!
If the default shell for your system is /bin/bash, then having the line:

Code:

shell=/bin/bash

in your script does nothing and your script is being run by bash. If the default shell for your system is NOT /bin/bash, then having the line:

Code:

shell=/bin/bash

in your script does nothing and your script is NOT being run by bash; it is being run by the default shell on your system.

If you type the command:

Code:

shell=/dev/null

into your shell, does the shell you are using magically change to /dev/null? NO. All it does is set a shell variable that later lines in your script (or, when done interactively, in your login session) can access by testing the value of $shell.

By convention (when your login shell is not a csh derivative), when you login the shell variable SHELL is exported and set by the system to an absolute pathname of your login shell. My login shell is /bin/ksh and after I login, $SHELL expands to /bin/ksh. If I then invoke bash, $SHELL still expands to /bin/ksh. Note also that case matters: $SHELL and $shell are two different variables.

If the script you are asking cron to run is an executable file and the 1st two characters in that file are #!, the system will use the interpreter named by the pathname on the rest of that line as the program used to interpret the rest of that file.

Now, back to your environment problem...
If you don't know what environment variables /opt/CPsuite-R77/fw1/bin/upgrade_tools/upgrade_export needs to have set in order for it to work correctly, you need to set all of the variables in your script to the same values that they have when you run /opt/CPsuite-R77/fw1/bin/upgrade_tools/upgrade_export manually and it works.

When you login with bash as your login shell, it runs three files from your home directory if they are present: .bash_profile, .bash_login, and .profile. If those files are where the variables /opt/CPsuite-R77/fw1/bin/upgrade_tools/upgrade_export needs to run are defined, the following might work for you. Change:

Code:

shell=/bin/bash

in your script to:

Code:

#!/bin/bash
HOME="/absolute/path/to/your/home/directory"
cd "$HOME"
[ -f .bash_profile ] && . .bash_profile
[ -f .bash_login ] && . .bash_login
[ -f .profile ] && . .profile

One would expect that one or more of those three files initializes PATH (although it appears that your script doesn't depend on any utilities that are not on the default PATH that you aren't referencing with absolute pathnames) and other shell variables to the values you'll need to run /opt/CPsuite-R77/fw1/bin/upgrade_tools/upgrade_export, but we can't know that for sure since we have no idea what other commands you have run after you last logged in to your system before you successfully run /opt/CPsuite-R77/fw1/bin/upgrade_tools/upgrade_export from your interactive shell. And, as we have repeatedly said, without knowing what /opt/CPsuite-R77/fw1/bin/upgrade_tools/upgrade_export is doing, we are just guessing. If /opt/CPsuite-R77/fw1/bin/upgrade_tools/upgrade_export tries to open your controlling terminal for some reason, it might just not be possible to run /opt/CPsuite-R77/fw1/bin/upgrade_tools/upgrade_export from cron at all.