What two preparations let log_manager.sh run directly as a Bash script?
log_manager.sh
Place #!/bin/bash on the first line and add execute permission with chmod +x.
#!/bin/bash
chmod +x
Add an echo command; its presence automatically selects Bash and grants execute permission.
Give the file an .sh extension; Linux then makes it executable automatically.
.sh
Put read BACKUP_FILENAME first and remove the shebang.
read BACKUP_FILENAME