gnucash/src/engine/gnc-filepath-utils.c

/********************************************************************\
 * gnc-filepath-utils.c -- file path resolutin utilitie             *
 *                                                                  *
 * This program 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.              *
 *                                                                  *
 * This program 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 this program; if not, contact:                        *
 *                                                                  *
 * Free Software Foundation           Voice:  +1-617-542-5942       *
 * 51 Franklin Street, Fifth Floor    Fax:    +1-617-542-2652       *
 * Boston, MA  02110-1301,  USA       gnu@gnu.org                   *
\********************************************************************/

/*
 * @file gnc-filepath-utils.c
 * @brief file path resolution utilities
 * @author Copyright (c) 1998-2004 Linas Vepstas <linas@linas.org>
 * @author Copyright (c) 2000 Dave Peticolas
 *
 * XXX this file does not belong in the gnucash engine; it is here
 * for the moment only because both the file backend and the app-file
 * GUI code make use of it.
 */

#include "config.h"

#include <glib.h>
#include <glib/gi18n.h>
#include <glib/gprintf.h>
#include <glib/gstdio.h>

#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <sys/types.h>
#include <sys/stat.h>
#ifdef HAVE_UNISTD_H
# include <unistd.h>
#endif
#include <errno.h>

#include "gnc-engine.h"
#include "gnc-path.h"
#include "gnc-filepath-utils.h"

#ifdef _MSC_VER
#include <glib/gwin32.h>
#define PATH_MAX MAXPATHLEN
#endif

static QofLogModule log_module = GNC_MOD_BACKEND;


/**
 * Scrubs a filename by changing "strange" chars (e.g. those that are not
 * valid in a win32 file name) to "_".
 *
 * @param filename File name - updated in place
 */
static void
scrub_filename(char* filename)
{
    char* p;

#define STRANGE_CHARS "/:"
    p = strpbrk(filename, STRANGE_CHARS);
    while (p)
    {
        *p = '_';
        p = strpbrk(filename, STRANGE_CHARS);
    }
}

/** \fn gchar * check_file_return_if_true (path)
 *  \brief Check if the path exists and is a regular file
 *
 * \param path -- freed if the path doesn't exist or isn't a regular file
 *
 *  \return NULL or the path
 */

static gchar *
check_path_return_if_valid(gchar *path)
{
    ENTER("Path: %s", path);
    if (g_file_test(path, G_FILE_TEST_IS_REGULAR))
    {
        LEAVE("found %s", path);
        return path;
    }
    g_free (path);
    return NULL;
}

/** @fn char * xaccResolveFilePath (const char * filefrag)
 *
 *  @brief Create an absolute path when given a relative path;
 *  otherwise return the argument.
 *
 * If passed a string which g_path_is_absolute declares an absolute
 * path, return the argument. If the string begins with file:,
 * file://, xml:, or xml://, remove that and return the rest.
 *
 * Otherwise, assume that filefrag is a well-formed relative path and
 * try to find a file with its path relative to the current working
 * directory, the installed system-wide data directory (e.g.,
 * /usr/local/share/gnucash), the installed system configuration
 * directory (e.g., /usr/local/etc/gnucash), or in the user's
 * configuration directory (e.g., $HOME/.gnucash/data) in that
 * order. If a matching file is found, return the absolute path to
 * it. If one isn't found, return a absolute path relative to the
 * user's configuration directory and note in the trace file that it
 * needs to be created.
 *
 * @param filefrag
 *
 * @return An absolute file path.
 */
char *
xaccResolveFilePath (const char * filefrag)
{
    int namelen;
    gchar *fullpath = NULL, *tmp_path = NULL;

    /* seriously invalid */
    if (!filefrag)
    {
        PERR("filefrag is NULL");
        return NULL;
    }

    ENTER ("filefrag=%s", filefrag);

    /* ---------------------------------------------------- */
    /* OK, now we try to find or build an absolute file path */

    /* check for an absolute file path */
    if (g_path_is_absolute(filefrag))
    {
        LEAVE("filefrag is absolute path");
        return g_strdup (filefrag);
    }

    if (!g_ascii_strncasecmp(filefrag, "file:", 5))
    {
        LEAVE("filefrag is file uri");
        if (!g_ascii_strncasecmp(filefrag, "file://", 7))
            return g_strdup(filefrag + 7);
        else
            return g_strdup(filefrag + 5);
    }
    if ( g_ascii_strncasecmp( filefrag, "xml:", 4 ) == 0 )
    {
        LEAVE( "filefrag is xml file uri" );
        if ( g_ascii_strncasecmp( filefrag, "xml://", 6 ) == 0 )
            return g_strdup( filefrag + 6);
        else
            return g_strdup( filefrag + 4);
    }


    /* get conservative on the length so that sprintf(getpid()) works ... */
    /* strlen ("/.LCK") + sprintf (%x%d) */
    namelen = strlen (filefrag) + 25;

    /* Look in the current working directory */
    tmp_path = g_get_current_dir();
    fullpath = g_build_filename(tmp_path, filefrag, (gchar *)NULL);
    g_free(tmp_path);
    fullpath = check_path_return_if_valid(fullpath);
    if (fullpath != NULL)
    {
        LEAVE("found %s", fullpath);
        return fullpath;
    }

    /* Look in the data dir (e.g. $PREFIX/share/gnucash) */
    tmp_path = gnc_path_get_pkgdatadir();
    fullpath = g_build_filename(tmp_path, filefrag, (gchar *)NULL);
    g_free(tmp_path);
    fullpath = check_path_return_if_valid(fullpath);
    if (fullpath != NULL)
    {
        LEAVE("found %s", fullpath);
        return fullpath;
    }

    /* Look in the config dir (e.g. $PREFIX/etc/gnucash) */
    tmp_path = gnc_path_get_accountsdir();
    fullpath = g_build_filename(tmp_path, filefrag, (gchar *)NULL);
    g_free(tmp_path);
    fullpath = check_path_return_if_valid(fullpath);
    if (fullpath != NULL)
    {
        LEAVE("found %s", fullpath);
        return fullpath;
    }

    /* Look in the users config dir (e.g. $HOME/.gnucash/data) */
    fullpath = gnc_build_data_path(filefrag);
    if (g_file_test(fullpath, G_FILE_TEST_IS_REGULAR))
    {
        LEAVE("found %s", fullpath);
        return fullpath;
    }
    /* OK, it's not there. Note that it needs to be created and pass it
     * back anyway */
    LEAVE("create new file %s", fullpath);
    return fullpath;

}

/* ====================================================================== */

/** @fn char * xaccResolveURL (const char * pathfrag)
 *
 *  @brief Return the passed-in string unless it starts with file:,
 *  xml:, or is a raw relative path.
 *
 * Strings starting with "http://, https://, or a "registered scheme"
 * (see qof_backend_get_registered_access_method_list()) are returned
 * as-is by this function.
 *
 * Strings which form an absolute path (as determined by
 * g_path_is_absolute()) are passed to xaccResolveFilePath() and
 * immediately returned as-is.
 *
 * Strings which begin with file: or xml: are passed to
 * xaccResolveFilePath, which strips off the "scheme" part (file: or
 * xml: plus // if present) and returns the rest unchanged. This
 * result is passed back to the caller as-is if the original astring
 * started with file:; if it started with xml:, then xml: is prepended
 * before passing it back to the caller. Note that this has the effect
 * of converting a URI of the form xml:///path/to/file into one of the
 * form xml:/path/to/file.
 *
 * Strings which meet none of the above are passed to
 * xaccResolveFilePath and the result returned to the caller.
 *
 * @param pathfrag the string to "resolve"
 *
 *  @return "resolved" string.
 */
char *
xaccResolveURL (const char * pathfrag)
{
    GList* list;
    GList* node;

    /* seriously invalid */
    if (!pathfrag) return NULL;

    /* At this stage of checking, URL's are always, by definition,
     * resolved.  If there's an error connecting, we'll find out later.
     */

    if (!g_ascii_strncasecmp (pathfrag, "http://", 7) ||
            !g_ascii_strncasecmp (pathfrag, "https://", 8))
    {
        return g_strdup(pathfrag);
    }

    /* Check the URL against the list of registered access methods */
    list = qof_backend_get_registered_access_method_list();
    for ( node = list; node != NULL; node = node->next )
    {
        const gchar* access_method = node->data;
        if ( strcmp( access_method, "file" ) != 0 &&
                strcmp( access_method, "xml" ) != 0 )
        {
            gchar s[30];
            sprintf( s, "%s://", access_method );
            if ( !g_ascii_strncasecmp( pathfrag, s, strlen(s) ) )
            {
                g_list_free(list);
                return g_strdup(pathfrag);
            }
        }
    }
    g_list_free(list);
    /*
     * xml: schemes are a special case, becuase gnc_file_do_save_as()
     * relies on the phony scheme id being present in the returned path
     * to distinguish the backend used to save the file. Note that this
     * has the amusing effect of stripping the // from the phony scheme,
     * so if it started out as xml:///path/to/data, it gets returned
     * from here as xml:/path/to/data.
     */
    if (!g_ascii_strncasecmp (pathfrag, "xml:", 4))
    {
        return (g_strdup_printf( "xml:%s", xaccResolveFilePath (pathfrag)) );
    }
    return (xaccResolveFilePath (pathfrag));
}

/* ====================================================================== */

/** @fn void gnc_validate_directory (const gchar *dirname)
 *  @brief Check that the supplied directory path exists, is a directory, and that the user has adequate permissions to use it.
 *
 * @param dirname The path to check
 */
static void
gnc_validate_directory (const gchar *dirname)
{
    struct stat statbuf;
    gint rc;

    rc = g_stat (dirname, &statbuf);
    if (rc)
    {
        switch (errno)
        {
        case ENOENT:
            rc = g_mkdir (dirname,
#ifdef G_OS_WIN32
                          0          /* The mode argument is ignored on windows */
#else
                          S_IRWXU    /* perms = S_IRWXU = 0700 */
#endif
                         );
            if (rc)
            {
                g_fprintf(stderr,
                          _("An error occurred while creating the directory:\n"
                            "  %s\n"
                            "Please correct the problem and restart GnuCash.\n"
                            "The reported error was '%s' (errno %d).\n"),
                          dirname, g_strerror(errno) ? g_strerror(errno) : "", errno);
                exit(1);
            }
            g_stat (dirname, &statbuf);
            break;

        case EACCES:
            g_fprintf(stderr,
                      _("The directory\n"
                        "  %s\n"
                        "exists but cannot be accessed.  This program \n"
                        "must have full access (read/write/execute) to \n"
                        "the directory in order to function properly.\n"),
                      dirname);
            exit(1);

        case ENOTDIR:
            g_fprintf(stderr,
                      _("The path\n"
                        "  %s\n"
                        "exists but it is not a directory. Please delete\n"
                        "the file and start GnuCash again.\n"),
                      dirname);
            exit(1);

        default:
            g_fprintf(stderr,
                      _("An unknown error occurred when validating that the\n"
                        "  %s\n"
                        "directory exists and is usable. Please correct the\n"
                        "problem and restart GnuCash.  The reported error \n"
                        "was '%s' (errno %d)."),
                      dirname, g_strerror(errno) ? g_strerror(errno) : "", errno);
            exit(1);
        }
    }

    if ((statbuf.st_mode & S_IFDIR) != S_IFDIR)
    {
        g_fprintf(stderr,
                  _("The path\n"
                    "  %s\n"
                    "exists but it is not a directory. Please delete\n"
                    "the file and start GnuCash again.\n"),
                  dirname);
        exit(1);
    }
#ifndef G_OS_WIN32
    /* The mode argument is ignored on windows anyway */
    if ((statbuf.st_mode & S_IRWXU) != S_IRWXU)
    {
        g_fprintf(stderr,
                  _("The permissions are wrong on the directory\n"
                    "  %s\n"
                    "They must be at least 'rwx' for the user.\n"),
                  dirname);
        exit(1);
    }
#endif
}

/** @fn const gchar * gnc_dotgnucash_dir ()
 *  @brief Ensure that the user's configuration directory exists and is minimally populated.
 *
 *  Note that the default path is $HOME/.gnucash; This can be changed
 *  by the environment variable $GNC_DOT_DIR.
 *
 *  @return An absolute path to the configuration directory
 */
const gchar *
gnc_dotgnucash_dir (void)
{
    static gchar *dotgnucash = NULL;
    gchar *tmp_dir;

    if (dotgnucash)
        return dotgnucash;

    dotgnucash = g_strdup(g_getenv("GNC_DOT_DIR"));

    if (!dotgnucash)
    {
        const gchar *home = g_get_home_dir();
        if (!home)
        {
            g_warning("Cannot find home directory. Using tmp directory instead.");
            home = g_get_tmp_dir();
        }
        g_assert(home);

        dotgnucash = g_build_filename(home, ".gnucash", (gchar *)NULL);
    }
    gnc_validate_directory(dotgnucash);

    /* Since we're in code that is only executed once.... */
    tmp_dir = g_build_filename(dotgnucash, "books", (gchar *)NULL);
    gnc_validate_directory(tmp_dir);
    g_free(tmp_dir);
    tmp_dir = g_build_filename(dotgnucash, "checks", (gchar *)NULL);
    gnc_validate_directory(tmp_dir);
    g_free(tmp_dir);

    return dotgnucash;
}

/** @fn gchar * gnc_build_dotgnucash_path (const gchar *filename)
 *  @brief Make a path to filename in the user's configuration directory.
 *
 * @param filename The name of the file
 *
 *  @return An absolute path.
 */

gchar *
gnc_build_dotgnucash_path (const gchar *filename)
{
    return g_build_filename(gnc_dotgnucash_dir(), filename, (gchar *)NULL);
}

/** @fn gchar * gnc_build_book_path (const gchar *filename)
 *  @brief Make a path to filename in the book subdirectory of the user's configuration directory.
 *
 * @param filename The name of the file
 *
 *  @return An absolute path.
 */

gchar *
gnc_build_book_path (const gchar *filename)
{
    gchar* filename_dup = g_strdup(filename);
    gchar* result = NULL;

    scrub_filename(filename_dup);
    result = g_build_filename(gnc_dotgnucash_dir(), "books",
                              filename_dup, (gchar *)NULL);
    g_free(filename_dup);
    return result;
}

/** @fn gchar * gnc_build_data_path (const gchar *filename)
 *  @brief Make a path to filename in the data subdirectory of the user's configuration directory.
 *
 * @param filename The name of the file
 *
 *  @return An absolute path.
 */

gchar *
gnc_build_data_path (const gchar *filename)
{
    gchar* filename_dup = g_strdup(filename);
    gchar* result;

    scrub_filename(filename_dup);
    result = g_build_filename(gnc_dotgnucash_dir(), "data", filename_dup, (gchar *)NULL);
    g_free(filename_dup);
    return result;
}

/* =============================== END OF FILE ========================== */