Disable crontab's remove option in CLI

Solution 1:

I suggest that you include

alias crontab="crontab -i"

in your ~/.bashrc file (start a new shell before testing!)

This means that every time you run crontab, you always select the "-i" option. If you now give the crontab -r command, it is processed at crontab -ir, which prompts before removing the crontab file:

nick@serv2:~$ crontab -r
crontab: really delete nick's crontab? (y/n) n

Solution 2:

Use a wrapper around the crontabcommand, for example this function would do:

crontab () { [[ $@ =~ -[iel]*r ]] && echo '"r" not allowed' || command crontab "$@" ;}

This function checks if -r exists in the argument of crontab; if so, exits with the message "r" not allowed, otherwise executes the command.

Put it in your ~/.bashrc to get it loaded upon initialization of all interactive bash sessions.