Programming

#include <stdio.h>
#include <string.h>
#include <sqlca.h>
#include <alloca.h>

/* Define constants for VARCHAR lengths. */
#define UNAME_LEN 20
#define PWD_LEN 40

struct rec{
char *ename;
float salary;
float commission;
struct rec *lnk;
};

int main(){

    struct rec *ll;
    ll=NULL;    
    
    dbs(&ll);
    
    display(ll);
    
    return 1;
}


void dbs(struct rec **ll){

    int total_queried = 0;
    struct rec *t,*r,*q;

    EXEC SQL BEGIN DECLARE SECTION;

    struct rec1{
        VARCHAR emp_name[UNAME_LEN];
        float salary;
        float commission;
    };
    struct
    {
        short name_ind;
        short sal_ind;
        short comm_ind;
    } emprec_ind;

    VARCHAR uid[80];
    VARCHAR pwd[20];

    struct rec1 emprec;

    EXEC SQL END DECLARE SECTION;

    strcpy(uid.arr,"hr");
    uid.len =strlen(uid.arr);
    strcpy(pwd.arr,"hr");
    pwd.len = strlen(pwd.arr);
    
    EXEC SQL WHENEVER SQLERROR DO sql_error("ORACLE error--\n");

    EXEC SQL CONNECT :uid IDENTIFIED BY :pwd;

    EXEC SQL DECLARE e_cursor CURSOR FOR SELECT FIRST_NAME,SALARY, COMMISSION_PCT FROM EMPLOYEES;

    EXEC SQL OPEN e_cursor;

    EXEC SQL WHENEVER NOT FOUND DO break;
    printf("\n1");
    while(1)
    {
        EXEC SQL FETCH e_cursor INTO :emprec INDICATOR :emprec_ind;
        emprec.emp_name.arr[emprec.emp_name.len] = '\0';
        total_queried++;        
        printf("\n2");
        if(*ll == NULL)
        {

            t=malloc(sizeof(struct rec));
            printf("\n3");            
            strcpy(t->ename,emprec.emp_name.arr);
            printf("\n 1 ename = %s",t->ename);
            t->salary=emprec.salary;
            t->commission=emprec.commission;
            t->lnk=NULL;
            *ll=t;            
        }
        else{
            printf("\n in else");
            struct rec *q=NULL;    
            q=*ll;
            printf("\n34");            
            while(q->lnk != NULL)
                q=q->lnk;

            r=malloc(sizeof(struct rec));
            
            strcpy(r->ename,emprec.emp_name.arr);
            r->salary=emprec.salary;
            r->commission=emprec.commission;
            r->lnk=NULL;
            q->lnk=r;    
        }
    }
/* Disconnect from ORACLE. */
EXEC SQL COMMIT WORK RELEASE;

}

void display(struct rec *q){
    printf("\n\nEmployee\tSalary\t\tCommission\n");
    printf("--------\t------\t\t----------\n");
    while(q != NULL){

            printf("%-20s\t%8.2f\t\t",q->ename, q->salary);
            printf("%6.2f\n", q->commission);
            q=q->lnk;
    }
}


void sql_error(msg)
char *msg;
{
char err_msg[128];
int buf_len, msg_len;
EXEC SQL WHENEVER SQLERROR CONTINUE;
printf("\n%s\n", msg);
buf_len = sizeof (err_msg);
sqlglm(err_msg, &buf_len, &msg_len);
if (msg_len > buf_len)
msg_len = buf_len;
printf("%.*s\n", msg_len, err_msg);
EXEC SQL ROLLBACK RELEASE;
exit(1);
}

1
2
3
 1 ename = Steven
2
 in else
34
2
 in else
34
2
 in else
34
2
 in else
*** glibc detected *** ./ok: malloc(): memory corruption (fast): 0x0000000001176240 ***
======= Backtrace: =========
/lib/x86_64-linux-gnu/libc.so.6(+0x7a6e6)[0x7f64922246e6]
/lib/x86_64-linux-gnu/libc.so.6(+0x7c91c)[0x7f649222691c]
/lib/x86_64-linux-gnu/libc.so.6(__libc_malloc+0x6d)[0x7f64922283cd]
./ok[0x40108a]
./ok[0x4007f9]
/lib/x86_64-linux-gnu/libc.so.6(__libc_start_main+0xed)[0x7f64921cb30d]
./ok[0x400839]
======= Memory map: ========
00400000-00402000 r-xp 00000000 07:00 928861                             /home/dell/proc/ok
00601000-00602000 r--p 00001000 07:00 928861                             /home/dell/proc/ok
00602000-00603000 rw-p 00002000 07:00 928861                             /home/dell/proc/ok
0109f000-0118d000 rw-p 00000000 00:00 0                                  [heap]
7f648c000000-7f648c021000 rw-p 00000000 00:00 0 
7f648c021000-7f6490000000 ---p 00000000 00:00 0 
7f64909de000-7f64909f3000 r-xp 00000000 07:00 658486                     /lib/x86_64-linux-gnu/libgcc_s.so.1
7f64909f3000-7f6490bf2000 ---p 00015000 07:00 658486                     /lib/x86_64-linux-gnu/libgcc_s.so.1

else{
            printf("\n in else");
            struct rec *q=NULL;    
            q=*ll;

/*strcpy(t->ename,emprec.emp_name.arr);*/
t->ename=strdup(emprec.emp_name.arr);

/*strcpy(r->ename,emprec.emp_name.arr);*/
r->ename=strdup(emprec.emp_name.arr);