execli.c

/*
 * execli.c
 * $Id: execli.c,v 1.2 2005/12/08 20:42:39 bobi Exp $
 *
 * Copyright 2004 Bobi B., w1zard0f07@yahoo.com
 *
 * This file is part of hdl_dump.
 *
 * hdl_dump is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * hdl_dump is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with hdl_dump; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

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


/* reads up to `bytes' from the `pipe' and returns the number of bytes get */
int non_blocking_pipe_read(HANDLE pipe,
                           char *buffer,
                           size_t bytes)
{
    size_t bytes_orig = bytes;
    DWORD bytes_left;
    BOOL success;

    do { /* ask how much bytes could be get from the pipe */
        bytes_left = 0;
        success = PeekNamedPipe(pipe, NULL, 0, NULL, &bytes_left, NULL);
        if (success && bytes_left > 0) {
            DWORD bytes_readen;
            if (bytes_left > bytes)
                bytes_left = bytes;
            success = ReadFile(pipe, buffer, bytes_left, &bytes_readen, NULL);
            if (success) {
                bytes -= bytes_readen;
                buffer += bytes_readen;
            }
        }
    } while (success && bytes_left > 0 && bytes > 0);
    return (bytes_orig - bytes);
}


/* executes a command-line interface program and passes all output
   via `message_callback'; upon complete returns exit code */
__stdcall int
exec_cli(const char *file_path,
         const char *cmd_line,
         const char *current_dir,
         __stdcall int (*message_callback)(const char *output,
                                           size_t length))
{
#define READ_BUFFER_SIZE 1024

    HANDLE out_read = NULL, out_write = NULL;
    SECURITY_ATTRIBUTES sa;
    BOOL success;
    char command_line[512];
    DWORD exit_code = (DWORD)-1;

    memset(&sa, 0, sizeof(sa));
    sa.nLength = sizeof(sa);
    sa.bInheritHandle = TRUE;
    success = CreatePipe(&out_read, &out_write, &sa, 0);
    if (success) {
        STARTUPINFOA si;
        PROCESS_INFORMATION pi;

        memset(&si, 0, sizeof(si));
        si.cb = sizeof(si);
        si.hStdInput = INVALID_HANDLE_VALUE;
        si.hStdOutput = out_write;
        si.hStdError = out_write;
        si.dwFlags = STARTF_USESTDHANDLES;

        memset(&pi, 0, sizeof(pi));

        sprintf(command_line, "\"%s\" %s", file_path, cmd_line);
        success = CreateProcess(file_path, command_line, NULL, NULL,
                                TRUE, CREATE_NO_WINDOW, NULL, current_dir, &si, &pi);
        if (success) { /* wait 'till process is over and nothing left to read from stdout */
            char buffer[READ_BUFFER_SIZE];
            size_t bytes;
            BOOL process_alive;
            do {
                Sleep(10); /* fixes 100% CPU usage issue */
                process_alive = (GetExitCodeProcess(pi.hProcess, &exit_code) &&
                                 exit_code == STILL_ACTIVE);
                do { /* pipe all data to the caller */
                    bytes = non_blocking_pipe_read(out_read, buffer,
                                                   sizeof(buffer) /
                                                       sizeof(buffer[0]));
                    if (bytes > 0)
                        (*message_callback)(buffer, bytes);
                } while (bytes > 0);
            } while (process_alive || bytes > 0);
        }
        CloseHandle(out_read);
        CloseHandle(out_write);
    }
    return ((int)exit_code);
}


#if defined(_CONSOLE_TEST)

__stdcall int
callback(const char *output,
         size_t length)
{
    printf("%d: [%.*s]", length, length, output);
    return (0);
}


int main(int argc, char *argv[])
{
    printf("exit code: %d",
           exec_cli("./hdl_dump.exe",
                    "cdvd_info i:/KALIFORNIA.ISO",
                    "t:/p/ps2/hdl_dump/",
                    &callback));
    return (0);
}

#endif /* _CONSOLE_TEST defined? */