Manual Reference Pages - GROFF_TRACE (7)
groff_trace - groff macro package trace.tmac
groff -m trace
Elements in brackets denote optional arguments, and the ellipsis means
that there can be any number of arguments of this kind.
trace macro package of
can be a valuable tool for debugging documents written in the roff
A call stack trace is protocolled on standard error, that means, a
diagnostic message is emitted on entering and exiting of a macro call.
This greatly eases to track down an error in some macro.
This tracing process is activated by specifying the groff or troff
command line option
-m~trace. This works also with the
A finer control can be obtained by including the macro file within the
document by the groff macro call
.mso~trace.tmac. Only macros that are defined after this line are traced.
If some other macro package should be traced as well it must be specified
-m~trace on the command line.
The macro file
trace.tmac is unusual because it does not contain any macros to be called by a
Instead, the existing macro definition and appending facilities are
modified such that they display diagnostic messages.
In the following examples, a roff fragment is fed into groff via
As we are only interested in the diagnostic messages (standard error)
on the terminal, the normal formatted output (standard output) is
redirected into the nirvana device
/dev/null. The resulting diagnostic messages are displayed directly below the
Command line option
*** de trace enter: test_macro
*** trace exit: test_macro
*** de trace enter: test_macro "some" "dummy" "arguments"
*** trace exit: test_macro "some" "dummy" "arguments"
The entry and the exit of each macro call is displayed on the terminal
(standard output) [em] together with the arguments (if any).
Nested macro calls
*** de trace enter: parent
*** de trace enter: child
*** trace exit: child
*** trace exit: parent
This shows that macro calls can be nested.
This powerful feature can help to tack down quite complex call stacks.
Activating with .mso
*** de trace enter: after
*** trace exit: after
Here, the tracing is activated within the document, not by a command
As tracing was not active when macro
before was defined, no call of this macro is protocolled; on the other hand,
after is fully protocolled.
trace macros are kept in the file
trace.tmac located in the
tmac directory; see
A colon-separated list of additional tmac directories in which to
search for macro files; see
Copyright (C) 2002 Free Software Foundation, Inc.
This document is distributed under the terms of the FDL (GNU Free
Documentation License) version 1.1 or later.
You should have received a copy of the FDL on your system, it is also
available on-line at the
This document is part of
groff, the GNU roff distribution.
It was written by
A complete reference for all parts of the groff system is found in the
An overview of the groff system.
For details on option
A viewer program for all kinds of roff documents.
A general description of groff macro packages.
A short reference for the groff formatting language.
|Groff Version 1.19.2 ||GROFF_TRACE (7) ||24 March 2016 |
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