Hello,
I am experiencing seg faults in seemingly innocent code with MySQL version 4.0.0
and the embedded library, libmysqld.
The fault only happens when calling particular functions, specifically
mysql_ping() and mysql_query(). There might be others, but these are the only
ones I've found so far.
Following is the code:
/*
* A simple example client, using the embedded MySQL server library
*/
#include <mysql.h>
#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
MYSQL * db_connect();
void db_disconnect(MYSQL *db);
void db_query(MYSQL *db, const char *SQL);
static char *server_groups[] = {
"test_client_SERVER",
"server",
NULL
};
int main( int argc, char **argv) {
MYSQL *mysqldb;
mysql_server_init(argc, argv, server_groups);
mysqldb = db_connect();
/* grab some server information */
fprintf ( stderr, "host info: %s\n", mysql_get_host_info(mysqldb) );
fprintf ( stderr, "server info: %s\n", mysql_get_server_info(mysqldb) );
fprintf ( stderr, "protocol info: %d\n", mysql_get_proto_info(mysqldb) );
/* SEGFAULT HAPPENS HERE */
mysql_ping(mysqldb);
/* IF I TAKE OUT THE MYSQL_PING, SEGFAULT HAPPENS HERE */
mysql_query ( mysqldb, "SHOW TABLE STATUS" );
mysql_close( mysqldb );
mysql_server_end();
exit (0);
}
MYSQL *
db_connect() {
MYSQL *db = mysql_init(NULL);
if (!db)
fprintf ( stderr, "mysql_init failed: no memory.\n" );
fprintf ( stderr, "calling mysql_real_connect(): " );
if ( ! mysql_real_connect(db, NULL, NULL, NULL, NULL, 0, NULL, 0) )
fprintf ( stderr, "FAILURE: %s\n", mysql_error(db) );
else
fprintf ( stderr, "SUCCESS\n" );
return db;
}
void db_query(MYSQL *db, const char *SQL) {
int result;
fprintf ( stderr, "calling mysql_query(): " );
result = mysql_query (db, SQL );
if ( result == 0 ) fprintf ( stderr, "SUCCESS\n" );
else fprintf ( stderr, "FAILURE: %s\n", mysql_error(db) );
fprintf ( stderr, "result code: %d\n", result );
}
void db_disconnect(MYSQL *db) {
mysql_close(db);
}
The client seems to init the database okay, and it seems to connect okay, and it
even gathers information with the mysql_get_server_info, mysql_get_proto_info
and mysql_get_host info calls, but then mysteriously seg faults at the
mysql_ping or the mysql_query.
If anyone can spot any glaring mistakes in the code that might be the cause of
this, please let me know.
I compile the code with the following command:
gcc -g -W -Wall -D_THREAD_SAFE -D_REENTRANT -I/usr/include/mysql mysql.c
-L/usr/lib/mysql -static -lmysqld -lpthread -lz -lcrypt -lnsl -lm -lrt -o mysql
Greg Kurzawa
[EMAIL PROTECTED]
[EMAIL PROTECTED]
---------------------------------------------------------------------
Before posting, please check:
http://www.mysql.com/manual.php (the manual)
http://lists.mysql.com/ (the list archive)
To request this thread, e-mail <[EMAIL PROTECTED]>
To unsubscribe, e-mail <[EMAIL PROTECTED]>
Trouble unsubscribing? Try: http://lists.mysql.com/php/unsubscribe.php
