1GROFF_TRACE(7) Miscellaneous Information Manual GROFF_TRACE(7)
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6 groff_trace - groff macro package trace.tmac
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9 groff -m trace [options...] [files...]
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11 Elements in brackets denote optional arguments, and the ellipsis means
12 that there can be any number of arguments of this kind.
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15 The trace macro package of groff(1) can be a valuable tool for debug‐
16 ging documents written in the roff formatting language. A call stack
17 trace is protocolled on standard error, that means, a diagnostic mes‐
18 sage is emitted on entering and exiting of a macro call. This greatly
19 eases to track down an error in some macro.
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21 This tracing process is activated by specifying the groff or troff com‐
22 mand line option -m trace. This works also with the groffer(1) viewer
23 program. A finer control can be obtained by including the macro file
24 within the document by the groff macro call .mso trace.tmac. Only
25 macros that are defined after this line are traced.
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27 If some other macro package should be traced as well it must be speci‐
28 fied after -m trace on the command line.
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30 The macro file trace.tmac is unusual because it does not contain any
31 macros to be called by a user. Instead, the existing macro definition
32 and appending facilities are modified such that they display diagnostic
33 messages.
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36 In the following examples, a roff fragment is fed into groff via stan‐
37 dard input. As we are only interested in the diagnostic messages
38 (standard error) on the terminal, the normal formatted output (standard
39 output) is redirected into the nirvana device /dev/null. The resulting
40 diagnostic messages are displayed directly below the corresponding
41 example.
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43 Command line option
44 sh# echo '.
45 > .de test_macro
46 > ..
47 > .test_macro
48 > .test_macro some dummy arguments
49 > ' | groff -m trace >/dev/null
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51 *** de trace enter: test_macro
52 *** trace exit: test_macro
53 *** de trace enter: test_macro "some" "dummy" "arguments"
54 *** trace exit: test_macro "some" "dummy" "arguments"
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56 The entry and the exit of each macro call is displayed on the terminal
57 (standard output) — together with the arguments (if any).
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59 Nested macro calls
60 sh# echo '.
61 > .de child
62 > ..
63 > .de parent
64 > .child
65 > ..
66 > .parent
67 > ' | groff -m trace >/dev/null
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69 *** de trace enter: parent
70 *** de trace enter: child
71 *** trace exit: child
72 *** trace exit: parent
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74 This shows that macro calls can be nested. This powerful feature can
75 help to tack down quite complex call stacks.
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77 Activating with .mso
78 sh# echo '.
79 > .de before
80 > ..
81 > .mso trace.tmac
82 > .de after
83 > ..
84 > .before
85 > .after
86 > .before
87 > ' | groff >/dev/null
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89 *** de trace enter: after
90 *** trace exit: after
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92 Here, the tracing is activated within the document, not by a command
93 line option. As tracing was not active when macro before was defined,
94 no call of this macro is protocolled; on the other hand, the macro af‐
95 ter is fully protocolled.
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98 The trace macros are kept in the file trace.tmac located in the tmac
99 directory; see groff_tmac(5) for details.
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102 $GROFF_TMAC_PATH
103 A colon-separated list of additional tmac directories in which
104 to search for macro files; see groff_tmac(5) for details.
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107 Copyright (C) 2002 Free Software Foundation, Inc.
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109 This document is distributed under the terms of the FDL (GNU Free Docu‐
110 mentation License) version 1.1 or later. You should have received a
111 copy of the FDL on your system, it is also available on-line at the GNU
112 copyleft site ⟨http://www.gnu.org/copyleft/fdl.html⟩.
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114 This document is part of groff, the GNU roff distribution. It was
115 written by Bernd Warken ⟨bwarken@mayn.de⟩.
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118 groff(1)
119 An overview of the groff system.
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121 troff(1)
122 For details on option -m.
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124 groffer(1)
125 A viewer program for all kinds of roff documents.
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127 groff_tmac(5)
128 A general description of groff macro packages.
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130 groff(7)
131 A short reference for the groff formatting language.
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133 A complete reference for all parts of the groff system is found in the
134 groff info(1) file.
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138Groff Version 1.18.1.4 13 July 2002 GROFF_TRACE(7)