.\" $Id$
.\"
.Dd September 2, 2002
.Dt LIBCHK 1
.Os FreeBSD
.Sh NAME
.Nm libchk
.Nd checks shared library links of binaries
.Sh SYNOPSIS
.Nm
.Op Fl hsv
.Op Fl x Ar directory
.Op Ar directory ...
.Sh DESCRIPTION
.Nm
is a tool to help users obtain the following information:
.Bl -dash -compact -offset indent
.It
A list of executables that have unresolvable shared library links
.It
A list of shared libraries that are not referenced by any binary
.It
A list of binaries for each shared library that are linked with the
library
.El
.Pp
Directories that
.Nm
searches for executables and libraries include:
.Bl -column -compact -offset indent
.It Pa /bin
.It Pa /sbin
.It Pa /usr/bin
.It Pa /usr/games
.It Pa /usr/libexec
.It Pa /usr/sbin
.It Pa $LOCALBASE/bin
.It Pa $LOCALBASE/libexec
.It Pa $LOCALBASE/sbin
.It Pa $X11BASE/bin
.It Pa $X11BASE/libexec
.It Pa $X11BASE/sbin
.El
.Pp
And the directories listed in
.Ev PATH
and the library search path that
.Xr ldconfig 8
tells.  In addition, a user can specify additional directories to
search via the command line.
.Pp
e.g.:
.Dl $ libchk /home/*/bin
.Pp
The directory list is automatically optimized to avoid duplicated
search.
.Pp
.Nm
recursively looks into those directories and checks shared library
links for each binary.  If a dead library link is found, it is
immediately reported.
.Pp
When it is done though all directories,
.Nm
lists the shared libraries in the library search path that are not
referenced by (linked with) any binary.
.Pp
.Sh WARNING
Do not blindly delete libraries that
.Nm
reports as unreferenced, because there are many reasons that
.Nm
cannot perfectly detect if a shared library is referenced by:
.Bl -dash -offset indent
.It
A library may be referenced by an executable hidden under a user
directory or an application specific directory.
.Pp
.It
A library may be put there for future use.
.Pp
.It
A library on an NFS exported or NFS mounted file system may be
referenced by an executable on another host.
.Pp
.It
A library can be dynamically linked with by calling
.Xr dlopen 3 ,
which
.Nm
can never detect.
.El
.Pp
.Sh OPTIONS
The following command line arguments are supported:
.Pp
.Bl -tag -width "--verbose" -compact
.It Fl s
.It Fl -strict
By default,
.Nm
does not regard a reference to a library in the same directory as
dead, but this option makes
.Nm
warn of that as well.
.Pp
.It Fl v
.It Fl -verbose
Make a detailed report.
.Nm
will also check and report what executables and libraries each library
is referenced (used) by.
.Pp
.It Fl x Ar directory
.It Fl -exclude Ar directory
Exclude the specified directory from the list of directories that
.Nm
searches for executables and libraries.
.It Ar directory ...
Additional directories to search for binaries.
.El
.Sh ENVIRONMENT
.Bl -tag -width "LOCALBASE" -compact
.It Ev PATH
The command search path.
.It Ev LOCALBASE
The local base directory. (default:
.Pa /usr/local )
.It Ev X11BASE
The X11 base directory. (default:
.Pa /usr/X11R6 )
.El
.Sh SEE ALSO
.Xr ldconfig 8
.Sh BUGS
.Bl -dash -compact
.It
Currently,
.Nm
only checks
.Fx
ELF executables and libraries.
.El
.Sh AUTHORS
.An Akinori MUSHA Aq knu@iDaemons.org