#include <stdio.h>
#include <string.h>
#include <oci.h>

void checkerr(OCIError* err, sword status) {
    text errbuf[512];
    ub4 buflen;
    sb4 errcode;

    switch (status) {
    case OCI_SUCCESS:
        break;
    case OCI_SUCCESS_WITH_INFO:
        printf("Error - OCI_SUCCESS_WITH_INFO\n");
        break;
    case OCI_NEED_DATA:
        printf("Error - OCI_NEED_DATA\n");
        break;
    case OCI_NO_DATA:
        printf("Error - OCI_NO_DATA\n");
        break;
    case OCI_ERROR:
        OCIErrorGet(err, (ub4)1, (text *)NULL, &errcode,
            errbuf, (ub4) sizeof(errbuf), (ub4)OCI_HTYPE_ERROR);
        printf("Error - %s\n", errbuf);
        break;
    case OCI_INVALID_HANDLE:
        printf("Error - OCI_INVALID_HANDLE\n");
        break;
    case OCI_STILL_EXECUTING:
        printf("Error - OCI_STILL_EXECUTE\n");
        break;
    case OCI_CONTINUE:
        printf("Error - OCI_CONTINUE\n");
        break;
    default:
        break;
    }
}


void parse_connect_string(
    char* connect_str,  /* in   */
    text  username[30], /* out  */
    text  password[30], /* out  */
    text  dbname[30]  /* out  */
    ) {

    username[0] = 0;
    password[0] = 0;
    dbname[0] = 0;

    char* to = (char*)username;

    while (*connect_str) {
        if (*connect_str == '/') {
            *to = 0;
            to = (char*)password;
            connect_str++;
            continue;
        }
        if (*connect_str == '@') {
            *to = 0;
            to = (char*)dbname;
            connect_str++;
            continue;
        }
        *to = *connect_str;
        to++;
        connect_str++;
    }
    *to = 0;
}

int main(int argc, char* argv[]) {
    /*  (void) OCIInitialize((ub4) OCI_DEFAULT, (dvoid *)           0,
    (dvoid * (*)(dvoid *, size_t))         0,
    (dvoid * (*)(dvoid *, dvoid *, size_t))0,
    (void (*)(dvoid *, dvoid *))           0 ); */



    /* The environment handle defines a context in which all OCI functions are
    invoked. Each environment handle contains a memory cache, which allows for
    fast memory access. All memory allocation under the environment handle is
    done from this cache. Access to the cache is serialized if multiple
    threads try to allocate memory under the same environment handle. When
    multiple threads share a single environment handle, they may block on
    access to the cache. The environment handle is passed as the parent
    parameter to the OCIHandleAlloc() call to allocate all other handle types.
    Bind and define handles are allocated implicitly.
    */
    OCIEnv*       env;

    /* The error handle is passed as a parameter to most OCI calls. The error
    handle maintains information about errors that occur during an OCI
    operation. If an error occurs in a call, the error handle can be passed to
    OCIErrorGet() to obtain additional information about the error that
    occurred. Allocating the error handle is one of the first steps in an OCI
    application because most OCI calls require an error handle as one of its
    parameters. */
    OCIError*     err;

    OCIServer*    srv;
    OCISvcCtx*    svc;
    OCISession*   ses;

    text          username[30];
    text          password[30];
    text          dbname[30];

    sword         r;

    if (argc < 2) {
        printf("usage %s username/password[@dbname]\n");
        return -1;
    }

    parse_connect_string(argv[1], username, password, dbname);

    env = 0;
    err = 0;
    srv = 0;
    svc = 0;
    ses = 0;

    int len = 0;

    r = OCIEnvCreate(&env, OCI_DEFAULT, 0, 0, 0, 0, 0, 0);

    if (r != OCI_SUCCESS)  {
        printf("OCIEnvCreate failed!\n");
        goto clean_up;
    }

    OCIHandleAlloc(env, (dvoid**)&err, OCI_HTYPE_ERROR, 0, 0);
    OCIHandleAlloc(env, (dvoid**)&srv, OCI_HTYPE_SERVER, 0, 0);
    OCIHandleAlloc(env, (dvoid**)&svc, OCI_HTYPE_SVCCTX, 0, 0);
    OCIHandleAlloc(env, (dvoid**)&ses, OCI_HTYPE_SESSION, 0, 0);

    len = strlen((char*)dbname);
    r = OCIServerAttach(srv, err, dbname, len, (ub4)OCI_DEFAULT);
    if (r != OCI_SUCCESS) {
        checkerr(err, r);
        goto clean_up;
    }

    /* set attribute server context in the service context */
    OCIAttrSet(svc, OCI_HTYPE_SVCCTX, srv, 0, OCI_ATTR_SERVER, err);

    OCIAttrSet(ses, OCI_HTYPE_SESSION, username, strlen((char*)username), OCI_ATTR_USERNAME, err);
    OCIAttrSet(ses, OCI_HTYPE_SESSION, password, strlen((char*)password), OCI_ATTR_PASSWORD, err);

    r = OCISessionBegin(svc, err, ses, OCI_CRED_RDBMS, OCI_DEFAULT);
    checkerr(err, r);


clean_up:

    if (env) OCIHandleFree(env, OCI_HTYPE_ENV);
    if (err) OCIHandleFree(err, OCI_HTYPE_ERROR);
    if (srv) OCIHandleFree(srv, OCI_HTYPE_SERVER);
    if (svc) OCIHandleFree(svc, OCI_HTYPE_SVCCTX);

    OCITerminate(OCI_DEFAULT);

    return 0;
}

Description Resource    Path    Location    Type
make: *** [oci6linux] Error 1   oci6linux           C/C++ Problem
undefined reference to `OCIAttrSet' oci6linux.cpp   /oci6linux/src  line 154    C/C++ Problem
undefined reference to `OCIAttrSet' oci6linux.cpp   /oci6linux/src  line 156    C/C++ Problem
undefined reference to `OCIAttrSet' oci6linux.cpp   /oci6linux/src  line 157    C/C++ Problem
undefined reference to `OCIEnvCreate'   oci6linux.cpp   /oci6linux/src  line 134    C/C++ Problem
undefined reference to `OCIErrorGet'    oci6linux.cpp   /oci6linux/src  line 29 C/C++ Problem
undefined reference to `OCIHandleAlloc' oci6linux.cpp   /oci6linux/src  line 141    C/C++ Problem
undefined reference to `OCIHandleAlloc' oci6linux.cpp   /oci6linux/src  line 142    C/C++ Problem
undefined reference to `OCIHandleAlloc' oci6linux.cpp   /oci6linux/src  line 143    C/C++ Problem
undefined reference to `OCIHandleAlloc' oci6linux.cpp   /oci6linux/src  line 144    C/C++ Problem
undefined reference to `OCIHandleFree'  oci6linux.cpp   /oci6linux/src  line 165    C/C++ Problem
undefined reference to `OCIHandleFree'  oci6linux.cpp   /oci6linux/src  line 166    C/C++ Problem
undefined reference to `OCIHandleFree'  oci6linux.cpp   /oci6linux/src  line 167    C/C++ Problem
undefined reference to `OCIHandleFree'  oci6linux.cpp   /oci6linux/src  line 168    C/C++ Problem
undefined reference to `OCIServerAttach'    oci6linux.cpp   /oci6linux/src  line 147    C/C++ Problem
undefined reference to `OCISessionBegin'    oci6linux.cpp   /oci6linux/src  line 159    C/C++ Problem
undefined reference to `OCITerminate'   oci6linux.cpp   /oci6linux/src  line 170    C/C++ Problem

gcc cdemo81.c -I/usr/include/oracle/10.2.0.5/client64 -L/usr/lib/oracle/10.2.0.5/client64

/tmp/ccqr5hRx.o: In function `main':
cdemo81.c:(.text+0xd7): undefined reference to `OCIEnvCreate'
cdemo81.c:(.text+0x128): undefined reference to `OCIHandleAlloc'
cdemo81.c:(.text+0x151): undefined reference to `OCIHandleAlloc'
cdemo81.c:(.text+0x17a): undefined reference to `OCIHandleAlloc'
cdemo81.c:(.text+0x1a3): undefined reference to `OCIServerAttach'
cdemo81.c:(.text+0x1d3): undefined reference to `OCIAttrSet'
cdemo81.c:(.text+0x1fc): undefined reference to `OCIHandleAlloc'
cdemo81.c:(.text+0x238): undefined reference to `OCIAttrSet'
cdemo81.c:(.text+0x274): undefined reference to `OCIAttrSet'
cdemo81.c:(.text+0x29f): undefined reference to `OCISessionBegin'
cdemo81.c:(.text+0x2e7): undefined reference to `OCIAttrSet'
cdemo81.c:(.text+0x310): undefined reference to `OCIHandleAlloc'
cdemo81.c:(.text+0x351): undefined reference to `OCIHandleAlloc'
cdemo81.c:(.text+0x3a6): undefined reference to `OCIStmtPrepare'
cdemo81.c:(.text+0x41a): undefined reference to `OCIDefineByPos'
cdemo81.c:(.text+0x473): undefined reference to `OCIStmtExecute'
cdemo81.c:(.text+0x505): undefined reference to `OCIHandleAlloc'
cdemo81.c:(.text+0x572): undefined reference to `OCIStmtPrepare'
cdemo81.c:(.text+0x5c7): undefined reference to `OCIStmtPrepare'
cdemo81.c:(.text+0x659): undefined reference to `OCIBindByName'
cdemo81.c:(.text+0x6e6): undefined reference to `OCIBindByName'
cdemo81.c:(.text+0x76f): undefined reference to `OCIBindByName'
cdemo81.c:(.text+0x7f8): undefined reference to `OCIBindByName'
cdemo81.c:(.text+0x881): undefined reference to `OCIBindByName'
cdemo81.c:(.text+0x92e): undefined reference to `OCIBindByPos'
cdemo81.c:(.text+0x9e9): undefined reference to `OCIDefineByPos'
cdemo81.c:(.text+0xc18): undefined reference to `OCIStmtExecute'
cdemo81.c:(.text+0xcd1): undefined reference to `OCIStmtExecute'
cdemo81.c:(.text+0xd6e): undefined reference to `OCIStmtExecute'
cdemo81.c:(.text+0xdea): undefined reference to `OCITransCommit'
/tmp/ccqr5hRx.o: In function `checkerr':
cdemo81.c:(.text+0xf30): undefined reference to `OCIErrorGet'
/tmp/ccqr5hRx.o: In function `cleanup':
cdemo81.c:(.text+0xf9b): undefined reference to `OCIHandleFree'
collect2: ld returned 1 exit status

gcc cdemo81.c -I/usr/include/oracle/10.2.0.5/client64 -L/usr/lib/oracle/10.2.0.5/client64 -loci

cannot find -lociei