Seg fault on completing query
От | Chris Jewell |
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Тема | Seg fault on completing query |
Дата | |
Msg-id | 3E70A394.9080802@liv.ac.uk обсуждение исходный текст |
Ответы |
Re: Seg fault on completing query
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Список | pgsql-interfaces |
Hi, I'm working on a frontend to a Postgresql database. I've chosen C in which to work, mainly because I wanted to learn the language. So, I'm using the pqlib frontend library. The C source I have is below. I compile it (on linux) with gcc -g -Wall -lpq -oantibug antibug.c. When I run the executable, it prints out the query to the screen ok, but also prints a "Segmentation Fault" on completion of the list. Does anyone know why? How can I prevent this? Thanks, Chris J Source: /*************************************************************** A test C program to perform a SELECT query on tblantibiotic**on the bugswat database. ***************************************************************/ #include <stdio.h>#include <libpq-fe.h>#include <stdlib.h> void exit_nicely(PGconn * conn) { PQfinish(conn); printf("Abnormal exit"); exit(1); } int main() { /* Declare variables for the connection and getting results */ int num_records; PGconn *connect; PGresult*res; int i; char *name; /* Connect to the database */ connect = PQconnectdb("host = linux.chrisdomain dbname=antibugdb user=cjewell"); if (PQstatus(connect) == CONNECTION_BAD) { fprintf(stderr, "Could not connect to database"); fprintf(stderr, "Error: %s\n", PQerrorMessage(connect)); exit_nicely(connect); } /* Perform our query */ res = PQexec(connect, "SELECT * FROM tblactivity;"); if ((!res) || (PQresultStatus(res)!= PGRES_TUPLES_OK)) { fprintf(stderr, "SELECT query failed, error: %d\n", PQresultStatus(res)); fprintf(stderr, "Server error: %s\n", PQerrorMessage(connect)); PQclear(res); exit_nicely(connect); } num_records = PQntuples(res); /* put the number of tuples into num_records */ /* Now print out the results to the screen */ for(i=0; i < num_records; ++i) { sprintf(name, "%s", PQgetvalue(res,i, 0)); printf("%s\n", name); } PQclear(res); PQfinish(connect); return(0); } Output: [cjewell@chris cprogs]$ ./antibug good some poor none unknown Segmentation fault [cjewell@chris cprogs]$
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