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authorMatthias Wachs <wachs@net.in.tum.de>2013-06-24 09:27:07 +0000
committerMatthias Wachs <wachs@net.in.tum.de>2013-06-24 09:27:07 +0000
commitd42e0431346cfa1da13c9ac3156dcf1c96a97393 (patch)
treef837fc78603c4d77e5d3406fa1a9ba9425ff3be3 /doc/gnunet-c-tutorial.tex
parent9cc06d175c995c179728ea090e131d2e7319fce2 (diff)
Updating the tutorial section in the source and including
an updated version of the pdf about command line parsing. This update describes how a developer can check if a command line argument was set at all by initializing the variables storing the commandline arguments with a specific value and checking this value after the run function applied the commandline parsing.
Diffstat (limited to 'doc/gnunet-c-tutorial.tex')
-rw-r--r--doc/gnunet-c-tutorial.tex7
1 files changed, 6 insertions, 1 deletions
diff --git a/doc/gnunet-c-tutorial.tex b/doc/gnunet-c-tutorial.tex
index 8ad4d3019..86d68b84b 100644
--- a/doc/gnunet-c-tutorial.tex
+++ b/doc/gnunet-c-tutorial.tex
@@ -594,6 +594,8 @@ static int a_flag;
&GNUNET_GETOPT_set_one, &a_flag},
GNUNET_GETOPT_OPTION_END
};
+ string_option = NULL;
+ a_flag = GNUNET_SYSERR;
// ...
\end{lstlisting}
@@ -602,7 +604,10 @@ the {\tt --help} argument and error handling are taken care of when
using this approach. Other {\tt GNUNET\_GETOPT\_}-functions can be used
to obtain integer value options, increment counters, etc. You can
even write custom option parsers for special circumstances not covered
-by the available handlers.
+by the available handlers. To check if an argument was specified by the
+user you initialize the variable with a specific value (e.g. NULL for
+a string and GNUNET\_SYSERR for a integer) and check after parsing
+happened if the values were modified.
Inside the {\tt run} method, the program would perform the
application-specific logic, which typically involves initializing and