I used pexpect
to solve my problem in a python script, equivalent shell scripts should look similar conceptually
Instead of
mntMyDir = '/mnt/' + myDir
os.system('truecrypt ' + mntMyDir + '.tc ' + mntMyDir + ' --password=' + myPassword + ' --keyfiles= --protect-hidden=no')
os.chdir(mntMyDir + '/tree')
I used
mntMyDir = '/mnt/' + myDir
truecryptCmd = 'truecrypt ' + mntMyDir + '.tc ' + mntMyDir + ' --keyfiles= --protect-hidden=no'
child = pexpect.spawn(truecryptCmd)
child.expect('Enter password for ' + mntMyDir + '.tc: ')
child.sendline(myPassword)
child.wait()
os.chdir(mntMyDir + '/tree')