source: branches/samba-3.5.x/testprogs/win32/npecho/npecho_client2.c

/*
 * Simple Named Pipe Client
 * (C) 2005 Jelmer Vernooij <jelmer@samba.org>
 * (C) 2009 Stefan Metzmacher <metze@samba.org>
 * Published to the public domain
 */

#include <windows.h>
#include <stdio.h>

#define ECHODATA "Black Dog"

int main(int argc, char *argv[])
{
        HANDLE h;
        DWORD numread = 0;
        char *outbuffer = malloc(sizeof(ECHODATA)*2);
        BOOL small_reads = FALSE;
        DWORD state = 0;
        DWORD flags = 0;

        if (argc == 1) {
                goto usage;
        } else if (argc >= 3) {
                if (strcmp(argv[2], "large") == 0) {
                        small_reads = FALSE;
                } else if (strcmp(argv[2], "small") == 0) {
                        small_reads = TRUE;
                } else {
                        goto usage;
                }
        }

        h = CreateFile(argv[1], GENERIC_READ|GENERIC_WRITE, 0, NULL, OPEN_EXISTING, 0, NULL);
        if (h == INVALID_HANDLE_VALUE) {
                printf("Error opening: %d\n", GetLastError());
                return -1;
        }

        GetNamedPipeHandleState(h, &state, NULL, NULL, NULL, NULL, 0);

        if (state & PIPE_READMODE_MESSAGE) {
                printf("message read mode\n");
        } else {
                printf("byte read mode\n");
        }

        Sleep(5000);

        if (small_reads) {
                DWORD ofs, size, nread;
                const char *more = "";
                printf("small reads\n");
                numread = 0;
                ofs = 0;
                size = sizeof(ECHODATA)/2;
                if (ReadFile(h, outbuffer+ofs, size, &nread, NULL)) {
                        if (state & PIPE_READMODE_MESSAGE) {
                                printf("Error message mode small read succeeded\n");
                                return -1;
                        }
                } else if (GetLastError() == ERROR_MORE_DATA) {
                        if (!(state & PIPE_READMODE_MESSAGE)) {
                                printf("Error byte mode small read returned ERROR_MORE_DATA\n");
                                return -1;
                        }
                        more = " more data";
                } else {
                        printf("Error reading: %d\n", GetLastError());
                        return -1;
                }
                printf("Small Read: %d%s\n", nread, more);
                numread += nread;
                ofs = size;
                size = sizeof(ECHODATA) - ofs;
                if (!ReadFile(h, outbuffer+ofs, size, &nread, NULL)) {
                        printf("Error reading: %d\n", GetLastError());
                        return -1;
                }
                printf("Small Read: %d\n", nread);
                numread += nread;
        } else {
                printf("large read\n");
                if (!ReadFile(h, outbuffer, sizeof(ECHODATA)*2, &numread, NULL)) {
                        printf("Error reading: %d\n", GetLastError());
                        return -1;
                }
        }
        printf("Read: %s %d\n", outbuffer, numread);
        if (state & PIPE_READMODE_MESSAGE) {
                if (numread != sizeof(ECHODATA)) {
                        printf("message mode returned %d bytes should be %s\n",
                               numread, sizeof(ECHODATA));
                        return -1;
                }
        } else {
                if (numread != (sizeof(ECHODATA)*2)) {
                        printf("message mode returned %d bytes should be %s\n",
                               numread, (sizeof(ECHODATA)*2));
                        return -1;
                }
        }

        if (!ReadFile(h, outbuffer, sizeof(ECHODATA)*2, &numread, NULL)) {
                printf("Error reading: %d\n", GetLastError());
                return -1;
        }

        printf("Read: %s %d\n", outbuffer, numread);

        return 0;
usage:
        printf("Usage: %s pipename [read]\n", argv[0]);
        printf("  Where pipename is something like \\\\servername\\NPECHO\n");
        printf("  Where read is something 'large' or 'small'\n");
        return -1;
}