(1) When "xbase" is installed, an 'ls -al' on the target file returns...

  -rwxr-xr-x 1 root root 10560 Apr 15  2012 /usr/bin/zap

...and when the target file is invoked without arguments, the following is printed:

  Usage: zap filename...
  
  This program does not automatically reindex any indices.
  Use the reindex program to reindex any indexes associated
  with the database, or build your own program which executes 
  the PackDatabase() method after opening all the index files 
  associated with the database.

========================================================================

(2) When "linuxtv-dvb-apps" is installed, an 'ls -al' on the target file returns...

  -rwxr-xr-x 1 root root 18840 Nov 21  2012 /usr/bin/zap

...and when the target file is invoked without arguments, the following is printed:

  ZAP: A zapping application
  Copyright (C) 2004, 2005, 2006 Manu Abraham (man...<omitted>...com)
  Copyright (C) 2006 Andrew de Quincey (adq...<omitted>...net)
  
  usage: zap <options> as follows:
  -h                     help
  -adapter <id>          adapter to use (default 0)
  -frontend <id> frontend to use (default 0)
  -demux <id>            demux to use (default 0)
  -caslotnum <id>        ca slot number to use (default 0)
  -channels <filename>   channels.conf file.
  -secfile <filename>    Optional sec.conf file.
  -secid <secid> ID of the SEC configuration to use, one of:
  -nomoveca              Do not attempt to move CA descriptors from stream to programme level
  <channel name>

========================================================================

(Sadly, neither program seems to respond to '/usr/bin/zap --help' or to 'man zap', and 'apropos zap' doesn't help either...)