/*

 * Copyright (c) 2004, Richard Levitte <richard@levitte.org>

 * All rights reserved.

 *

 * Redistribution and use in source and binary forms, with or without

 * modification, are permitted provided that the following conditions

 * are met:

 * 1. Redistributions of source code must retain the above copyright

 *    notice, this list of conditions and the following disclaimer.

 * 2. Redistributions in binary form must reproduce the above copyright

 *    notice, this list of conditions and the following disclaimer in the

 *    documentation and/or other materials provided with the distribution.

 *

 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS

 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT

 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR

 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT

 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,

 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT

 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,

 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY

 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT

 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE

 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

 */

#include <stddef.h>

#include <stdlib.h>

#include <limits.h>

#include <string.h>

#include <sys/types.h>

#include <dirent.h>

#include <errno.h>

#ifndef LPDIR_H

# include "LPdir.h"

#endif

/*

 * The POSIXly macro for the maximum number of characters in a file path is

 * NAME_MAX.  However, some operating systems use PATH_MAX instead.

 * Therefore, it seems natural to first check for PATH_MAX and use that, and

 * if it doesn't exist, use NAME_MAX.

 */

#if defined(PATH_MAX)

# define LP_ENTRY_SIZE PATH_MAX

#elif defined(NAME_MAX)

# define LP_ENTRY_SIZE NAME_MAX

#endif

/*

 * Of course, there's the possibility that neither PATH_MAX nor NAME_MAX

 * exist.  It's also possible that NAME_MAX exists but is define to a very

 * small value (HP-UX offers 14), so we need to check if we got a result, and

 * if it meets a minimum standard, and create or change it if not.

 */

#if !defined(LP_ENTRY_SIZE) || LP_ENTRY_SIZE<255

# undef LP_ENTRY_SIZE

# define LP_ENTRY_SIZE 255

#endif

struct LP_dir_context_st {

    DIR *dir;

    char entry_name[LP_ENTRY_SIZE + 1];

};

const char *LP_find_file(LP_DIR_CTX **ctx, const char *directory)

{

    struct dirent *direntry = NULL;

    if (ctx == NULL || directory == NULL) {

        errno = EINVAL;

        return 0;

    }

    errno = 0;

    if (*ctx == NULL) {

        *ctx = (LP_DIR_CTX *)malloc(sizeof(LP_DIR_CTX));

        if (*ctx == NULL) {

            errno = ENOMEM;

            return 0;

        }

        memset(*ctx, '\0', sizeof(LP_DIR_CTX));

        (*ctx)->dir = opendir(directory);

        if ((*ctx)->dir == NULL) {

            int save_errno = errno; /* Probably not needed, but I'm paranoid */

            free(*ctx);

            *ctx = NULL;

            errno = save_errno;

            return 0;

        }

    }

    direntry = readdir((*ctx)->dir);

    if (direntry == NULL) {

        return 0;

    }

    strncpy((*ctx)->entry_name, direntry->d_name,

            sizeof((*ctx)->entry_name) - 1);

    (*ctx)->entry_name[sizeof((*ctx)->entry_name) - 1] = '\0';

    return (*ctx)->entry_name;

}

int LP_find_file_end(LP_DIR_CTX **ctx)

{

    if (ctx != NULL && *ctx != NULL) {

        int ret = closedir((*ctx)->dir);

        free(*ctx);

        switch (ret) {

        case 0:

            return 1;

        case -1:

            return 0;

        default:

            break;

        }

    }

    errno = EINVAL;

    return 0;

}