UNIX for Advanced & Expert Users

Hi ,
while doing FTP from mainframe to unix if the file we are sending is already existing in the server ,it is getting replaced.when i used sunique command,its not replacing but stil creates a copy of the file with .1 to .99 extension.is there any way to abort the file transfer if the file is already existing in the unix server 'without creating another copy'?
Can anyone plz help me on this.
Thanks in advance

Try setting read only permission to the existing file

Thank you so much for your reply.
yeah, we have to retain the existing file in the server.your first option is good.but how to check the existence of the file using ftp job (jcl program)?which command we hav to put apart from ipname,userid,pwd,binary,sendsite,put.. in the member? if the file exists it should abend also.

thanks in advance

I think you are taking your problem the wrong way :
you have to design the retention rule / renaming convention rules and frequency / archiving rule / transfer frequency ... of the global transfer process, so that no such conflict occur , you should redesign your transfer process instead of developping something that kills unexpected FTP attempt : you should prevent such attempt from design.