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! 4: So far, we have only parsed configuration data from files.
! 5: libConfuse can also parse buffers, or in-memory character
! 6: strings. We will use this to fix a problem in the previous code.
! 7: </p><p>
! 8: The problem is that without a configuration file, the hello program
! 9: will not print anything. We want it to at least print the standard
! 10: greeting "Hello, World!" if no configuration file is available.
! 11: </p><p>
! 12: We can't have a default value for a section that can be specified
! 13: multiple times (ie, a section with the CFGF_MULTI flag set).
! 14: Instead we will parse a default configuration string if no section
! 15: has been parsed:
! 16: </p><a id="listing6"></a><pre class="programlisting">
! 17: 1 #include <stdio.h>
! 18: 2 #include <confuse.h>
! 19: 3
! 20: 4 int main(void)
! 21: 5 {
! 22: 6 /* ... setup options ... */
! 23: 7
! 24: 8 cfg = cfg_init(opts, CFGF_NONE);
! 25: 9 cfg_parse(cfg, "hello.conf");
! 26: 10
! 27: 11 if(cfg_size(cfg, "greeting") == 0)
! 28: 12 {
! 29: 13 cfg_parse_buf(cfg, "greeting Hello {}");
! 30: 14 }
! 31: 15
! 32: 16 /* ... print the greetings ... */
! 33: 17 }
! 34: </pre><p>
! 35: Only the changes from the previous code is shown here. We check if
! 36: the size of the "greeting" section is zero (ie, no section has been
! 37: defined). In that case we call <code class="function">cfg_parse_buf()</code>
! 38: to parse a default in-memory string "greeting Hello {}". This
! 39: string defines a greeting section with title Hello, but without any
! 40: sub-options. This way we rely on the default values of the
! 41: (sub-)options "targets" and "repeat".
! 42: </p><p>
! 43: When this program is run, it issues the well-known standard greeting
! 44: "Hello, World!" if no configuration file is present.
! 45: </p></div><div class="navfooter"><hr /><table width="100%" summary="Navigation footer"><tr><td width="40%" align="left"><a accesskey="p" href="ar01s04.html">Prev</a> </td><td width="20%" align="center"> </td><td width="40%" align="right"> <a accesskey="n" href="ar01s06.html">Next</a></td></tr><tr><td width="40%" align="left" valign="top">4. Using sections </td><td width="20%" align="center"><a accesskey="h" href="index.html">Home</a></td><td width="40%" align="right" valign="top"> 6. Validating callback functions</td></tr></table></div></body></html>
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