</Para>

<Para>

Seetheset(l)

man pagefor information on the arguments for these environment variables.

Refer tothe<command>SET</command> <acronym>SQL</acronym> command

for information on the arguments for these environment variables.

</Sect1>

</Sect1>

<Sect1>

<Title>

<FileName>libpq</FileName> Control Functions</Title>

<Para>

<ItemizedList>

<ListItem>

<Para>

<Function>PQsetNoticeProcessor</Function>

Control reporting of notice and warning messages generated by libpq.

<ProgramListing>

void PQsetNoticeProcessor (PGconn * conn,

void (*noticeProcessor) (void * arg, const char * message),

void * arg)

</ProgramListing>

</Para>

</ListItem>

</ItemizedList>

</Para>

<Para>

By default, <filename>libpq</filename> prints "notice" messages from the backend on stderr,

as well as a few error messages that it generates by itself.

This behavior can be overridden by supplying a callback function that

does something else with the messages. The callback function is passed

the text of the error message (which includes a trailing newline), plus

a void pointer that is the same one passed to <function>PQsetNoticeProcessor</function>.

(This pointer can be used to access application-specific state if needed.)

The default notice processor is simply

<ProgramListing>

static void

defaultNoticeProcessor(void * arg, const char * message)

{

fprintf(stderr, "%s", message);

}

</ProgramListing>

<Para>

To use a special notice processor, call <function>PQsetNoticeProcessor</function> just after

any creation of a new PGconn object.

</Sect1>

<Sect1>

<Title>User Authentication Functions</Title>

</Sect1>

<Sect1>

<Title>BUGS</Title>

<Title>Caveats</Title>

<Para>

The query buffer is 8192 bytes long, and queries over