1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
|
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<HTML
><HEAD
><TITLE
>Loading pgtcl into an Application</TITLE
><META
NAME="GENERATOR"
CONTENT="Modular DocBook HTML Stylesheet Version 1.7"><LINK
REV="MADE"
HREF="mailto:pgsql-docs@postgresql.org"><LINK
REL="HOME"
TITLE="PostgreSQL Tcl Interface Documentation"
HREF="index.html"><LINK
REL="UP"
TITLE="pgtcl - Tcl Binding Library"
HREF="libpgtcl.html"><LINK
REL="PREVIOUS"
TITLE="pgtcl - Tcl Binding Library"
HREF="libpgtcl.html"><LINK
REL="NEXT"
TITLE="pgtcl Command Reference"
HREF="libpgtcl-ref.html"><LINK
REL="STYLESHEET"
TYPE="text/css"
HREF="stylesheet.css"><META
NAME="creation"
CONTENT="2005-11-27T13:24:31"></HEAD
><BODY
CLASS="SECT1"
><DIV
CLASS="NAVHEADER"
><TABLE
SUMMARY="Header navigation table"
WIDTH="100%"
BORDER="0"
CELLPADDING="0"
CELLSPACING="0"
><TR
><TH
COLSPAN="5"
ALIGN="center"
VALIGN="bottom"
>PostgreSQL Tcl Interface Documentation</TH
></TR
><TR
><TD
WIDTH="10%"
ALIGN="left"
VALIGN="top"
><A
HREF="libpgtcl.html"
ACCESSKEY="P"
>Prev</A
></TD
><TD
WIDTH="10%"
ALIGN="left"
VALIGN="top"
><A
HREF="libpgtcl.html"
>Fast Backward</A
></TD
><TD
WIDTH="60%"
ALIGN="center"
VALIGN="bottom"
>Chapter 1. <SPAN
CLASS="APPLICATION"
>pgtcl</SPAN
> - Tcl Binding Library</TD
><TD
WIDTH="10%"
ALIGN="right"
VALIGN="top"
><A
HREF="libpgtcl.html"
>Fast Forward</A
></TD
><TD
WIDTH="10%"
ALIGN="right"
VALIGN="top"
><A
HREF="libpgtcl-ref.html"
ACCESSKEY="N"
>Next</A
></TD
></TR
></TABLE
><HR
ALIGN="LEFT"
WIDTH="100%"></DIV
><DIV
CLASS="SECT1"
><H1
CLASS="SECT1"
><A
NAME="LIBPGTCL-LOADING"
>1.2. Loading <SPAN
CLASS="APPLICATION"
>pgtcl</SPAN
> into an Application</A
></H1
><P
> Before using <SPAN
CLASS="APPLICATION"
>pgtcl</SPAN
> commands, you must load
the <TT
CLASS="FILENAME"
>libpgtcl</TT
> library into your Tcl application. This is normally
done with the <TT
CLASS="LITERAL"
>package require</TT
> command. Here is an example:
</P><PRE
CLASS="PROGRAMLISTING"
>package require Pgtcl 1.5</PRE
><P>
<TT
CLASS="LITERAL"
>package require</TT
> loads the <TT
CLASS="LITERAL"
>libpgtcl</TT
>
shared library, and loads any additional Tcl code that is part of the
<TT
CLASS="LITERAL"
>Pgtcl</TT
> package. Note that you can manually generate the pkgIndex.tcl file, or use <TT
CLASS="COMMAND"
>make pkgIndex.tcl</TT
> or <TT
CLASS="COMMAND"
>make pkgIndex.tcl-hand</TT
> to have make generate it.
</P
><P
> The old way to load the shared library is by using the
Tcl <TT
CLASS="LITERAL"
>load</TT
> command. Here is an example:
</P><PRE
CLASS="PROGRAMLISTING"
>load libpgtcl[info sharedlibextension]</PRE
><P>
Although this way of loading the shared library is deprecated, we
continue to document it for the time being, because it may help
in debugging if, for some reason, <TT
CLASS="LITERAL"
>package require</TT
>
is failing.
The use of <TT
CLASS="LITERAL"
>info sharedlibextension</TT
> is recommended in
preference to hard-wiring <TT
CLASS="LITERAL"
>.so</TT
> or <TT
CLASS="LITERAL"
>.sl</TT
> or
<TT
CLASS="LITERAL"
>.dll</TT
> into
the program.
</P
><P
> The <TT
CLASS="LITERAL"
>load</TT
> command will fail unless the system's dynamic
loader knows where to look for the <TT
CLASS="FILENAME"
>libpgtcl</TT
> shared
library file. You may need to work with <TT
CLASS="COMMAND"
>ldconfig</TT
>, or
set the environment variable <TT
CLASS="ENVAR"
>LD_LIBRARY_PATH</TT
>, or use
some equivalent facility for your platform to make it work. Refer
to the <SPAN
CLASS="PRODUCTNAME"
>PostgreSQL</SPAN
> installation instructions for
more information.
</P
><P
> <TT
CLASS="FILENAME"
>libpgtcl</TT
> in turn depends on the interface library
<TT
CLASS="FILENAME"
>libpq</TT
>, so the
dynamic loader must also be able to find the <TT
CLASS="FILENAME"
>libpq</TT
> shared
library. In practice this is seldom an issue, since both of these
shared libraries are normally stored in the same directory, but it
can be a stumbling block in some configurations.
</P
><P
> If you use a custom executable for your application, you might choose
to statically bind <TT
CLASS="FILENAME"
>libpgtcl</TT
> into the executable and thereby
avoid the <TT
CLASS="LITERAL"
>load</TT
> command and the potential problems of dynamic
linking. See the source code for <SPAN
CLASS="APPLICATION"
>pgtclsh</SPAN
> for an example.
</P
></DIV
><DIV
CLASS="NAVFOOTER"
><HR
ALIGN="LEFT"
WIDTH="100%"><TABLE
SUMMARY="Footer navigation table"
WIDTH="100%"
BORDER="0"
CELLPADDING="0"
CELLSPACING="0"
><TR
><TD
WIDTH="33%"
ALIGN="left"
VALIGN="top"
><A
HREF="libpgtcl.html"
ACCESSKEY="P"
>Prev</A
></TD
><TD
WIDTH="34%"
ALIGN="center"
VALIGN="top"
><A
HREF="index.html"
ACCESSKEY="H"
>Home</A
></TD
><TD
WIDTH="33%"
ALIGN="right"
VALIGN="top"
><A
HREF="libpgtcl-ref.html"
ACCESSKEY="N"
>Next</A
></TD
></TR
><TR
><TD
WIDTH="33%"
ALIGN="left"
VALIGN="top"
><SPAN
CLASS="APPLICATION"
>pgtcl</SPAN
> - Tcl Binding Library</TD
><TD
WIDTH="34%"
ALIGN="center"
VALIGN="top"
><A
HREF="libpgtcl.html"
ACCESSKEY="U"
>Up</A
></TD
><TD
WIDTH="33%"
ALIGN="right"
VALIGN="top"
><SPAN
CLASS="APPLICATION"
>pgtcl</SPAN
> Command Reference</TD
></TR
></TABLE
></DIV
></BODY
></HTML
>
|
