NAME
grofftrace - groff macro package trace.tmac
SYNOPSIS
ggrrooffff -mm ttrraaccee [options...] [files...]
Elements in brackets denote optional arguments, and the ellipsis means
that there can be any number of arguments of this kind.
DESCRIPTION
The trace macro package of ggrrooffff(1) can be a valuable tool for debug-
ging documents written in the roff formatting language. A call stack
trace is protocolled on standard error, that means, a diagnostic mes-
sage 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 com-
mand line option -mm ttrraaccee. This works also with the ggrrooffffeerr(1) viewer
program. A finer control can be obtained by including the macro file
within the document by the groff macro call ..mmssoo ttrraaccee..ttmmaacc. Only
macros that are defined after this line are traced.
If some other macro package should be traced as well it must be speci-
fied after -mm ttrraaccee on the command line.
The macro file ttrraaccee..ttmmaacc is unusual because it does not contain any
macros to be called by a user. Instead, the existing macro definition
and appending facilities are modified such that they display diagnostic
messages.
EEXXAAMMPPLLEESS
In the following examples, a roff fragment is fed into groff via stan-
dard input. 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 corresponding
example.
CCoommmmaanndd lliinnee ooppttiioonn
sh# echo '.
> .de testmacro
> ..
> .testmacro
> .testmacro some dummy arguments
> ' | groff -m trace >/dev/null
*** de trace enter: testmacro
*** trace exit: testmacro
*** de trace enter: testmacro "some" "dummy" "arguments"
*** trace exit: testmacro "some" "dummy" "arguments"
The entry and the exit of each macro call is displayed on the terminal
(standard output) - together with the arguments (if any).
NNeesstteedd mmaaccrroo ccaallllss
sh# echo '.
> .de child
> ..
> .de parent
> .child
> ..
> .parent
> ' | groff -m trace >/dev/null
*** 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.
AAccttiivvaattiinngg wwiitthh ..mmssoo
sh# echo '.
> .de before
> ..
> .mso trace.tmac
> .de after
> ..
> .before
> .after
> .before
> ' | groff >/dev/null
*** de trace enter: after
*** trace exit: after
Here, the tracing is activated within the document, not by a command
line option. As tracing was not active when macro before was defined,
no call of this macro is protocolled; on the other hand, the macro af-
ter is fully protocolled.
FILES The trace macros are kept in the file ttrraaccee..ttmmaacc located in the tmac
directory; see ggrrooffffttmmaacc(5) for details.
ENVIRONMENT $$GGRROOFFFFTTMMAACCPPAATTHH
A colon-separated list of additional tmac directories in which
to search for macro files; see ggrrooffffttmmaacc(5) for details.
AUTHOR Copyright (C) 2002 Free Software Foundation, Inc.
This document is distributed under the terms of the FDL (GNU Free Docu-
mentation 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 GGNNUU
ccooppyylleefftt ssiittee .
This document is part of groff, the GNU roff distribution. It was
written by
BBeerrnndd WWaarrkkeenn .
SEE ALSO
ggrrooffff(1)
An overview of the groff system.
ttrrooffff(1)
For details on option -mm.
ggrrooffffeerr(1)
A viewer program for all kinds of roff documents.
ggrrooffffttmmaacc(5)
A general description of groff macro packages.
ggrrooffff(7)
A short reference for the groff formatting language.
A complete reference for all parts of the groff system is found in the
groff iinnffoo(1) file.
Groff Version 1.19.1 18 July 2003 GROFFTRACE(7)