.TH BLACK-HAT 1 local
.SH NAME
black-hat \- finds and displays a black-hole path
.SH SYNOPSIS
.B black-hat
[PROGNAME] [OPTION]... 
.SH DESCRIPTION
.I black-hat
is a one-shot tool for displaying a simple trace of a
program containing a black-hole error. The trace shows the
pattern of function reductions from the first variable in the
black hole, to the next appearance of that variable. 

Note that the traced program must first be compiled using the
Hat tracing tools, and executed to generate a trace file. 
.SH OPTIONS
Possible options are as follows:
.TP
.BI --showqual[=(t,f)]
control whether to show functions qualified by the name
of their module
.TP
.BI --cutoff=DEPTH
subexpressions in printed expressions are cut off and
replaced with a placeholder below a depth of DEPTH
.TP
.BI --showrt[=(t,f)]
control whether to show the root of the search path, or
just the path from the black-hole variable
.TP
.BI  --srcref[=(t,f)]
control whether to show source references for each
expression on the path
.TP
.BI  --showcount[=(t,f)]
control whether to show the number of accesses to the
file nodes
.TP
.BI  --shownode[=(t,f)]
(DEBUGGING OPTION)
control whether to show the octal addresses of the
expression nodes, along side the pretty-printed versions

.SH AUTHOR
Written by Mike Dodds.
.SH REPORTING BUGS
Report bugs to <hat@haskell.org>
.SH COPYRIGHT
Copyright \(co 2004 University of York.
.br
This is free software without warranty of any kind.
.SH SEE ALSO
.I hat-nonterm
is one of many tools in the
.I Hat
tracing system for Haskell programs.
For further information about
.I Hat
see
.B http://haskell.org/hat