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LIBMAP.CONF(5)		       File Formats Manual		  LIBMAP.CONF(5)

NAME
     libmap.conf -- configuration file for dynamic object dependency mapping

DESCRIPTION
     The  libmap functionality of ld-elf.so.1(1) allows dynamic object dependen-
     cies to be mapped to arbitrary names.

     The configuration file consists of two whitespace	separated  columns;  the
     left  hand  side  containing  the mapping candidate and the right hand side
     containing the mapping.  Dependencies are matched	against  candidates  and
     replaced with the mappings.

     Constrained  mappings  may  be  specified by enclosing the name of the exe-
     cutable or library in brackets.  All mappings following a	constraint  will
     only  be  evaluated  for  that constraint.  Constraints can be one of three
     types:

     Exact   The constraint is matched literally so that only an executable with
	     an identical fully qualified pathname will  match	the  constraint.
	     This  means  that the executable /usr/bin/foo will not match a con-
	     straint for /usr/bin/./foo and vice-versa.   This	is  the  default
	     constraint type.

     Basename
	     A	constraint  with  no path is matched against the basename of the
	     executable.  foo will match /bin/foo, /usr/local/sbin/foo,  or  any
	     other executable named foo, no matter what its path is.

     Directory
	     A	constraint  with  a trailing slash is prefix-matched against the
	     full pathname of the executable.  /usr/bin/  will	match  any  exe-
	     cutable with a path starting with /usr/bin.

     Note  that  the executable path matched against is the path parameter in an
     exec*() function call.  The Directory or Exact constraints can  only  match
     when the executable is called with a full pathname.  Most programs executed
     from  a  shell  are  run without a full path, via exec*p(), so the Basename
     constraint type is the most useful.

     WARNING!  Constrained mappings must never appear first in the configuration
     file.  While there is a way to specify the "default" constraint, its use is
     not recommended.

     The most common use at the date of writing is for allowing  multiple  POSIX
     threading	libraries  to  be used on a system without relinking or changing
     symlinks.

EXAMPLES
     # /etc/libmap.conf
     #
     # candidate	     mapping
     #
     libpthread.so.1	     libpthread.so.1 # Everything uses 'libpthread'
     libpthread.so	     libpthread.so

     libc_r.so.5	     libpthread.so.1 # Everything that uses 'libc_r'
     libc_r.so		     libpthread.so   # now uses 'libpthread'

     [/tmp/mplayer]	     # Test version of mplayer uses libc_r
     libpthread.so.1	     libc_r.so.5
     libpthread.so	     libc_r.so

     [mplayer]		     # All other mplayers use libpthread
     libpthread.so.1	     libpthread.so.1
     libpthread.so	     libpthread.so

     [/usr/local/jdk1.4.1/]  # All Java 1.4.1 programs use libthr
			     # This works because "javavms" executes
			     # programs with the full pathname
     libpthread.so.1	     libthr.so.1
     libpthread.so	     libthr.so

FILES
     /etc/libmap.conf  The libmap configuration file.

SEE ALSO
     ldd(1), rtld(1)

HISTORY
     The libmap.conf manual page and  libmap  functionality  first  appeared  in
     FreeBSD 5.1.

AUTHORS
     This manual page was written by Matthew N. Dodd <winter@jurai.net>.

FreeBSD 5.4			January 31, 2004		  LIBMAP.CONF(5)
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