The command line version of exec offers "-a name", and the various library/syscall forms allow you to specify argv[0] separately from the path of the binary to

The command line version of exec offers "-a name", and the various library/syscall forms allow you to specify argv[0] separately from the path of the binary to exec. You can set it yourself within a running program as well, like: perl -e '$0="testme";while(1){sleep 1}' & ps -ef | grep testme