diff options
Diffstat (limited to 'compat/dbminit.c')
| -rw-r--r-- | compat/dbminit.c | 115 |
1 files changed, 115 insertions, 0 deletions
diff --git a/compat/dbminit.c b/compat/dbminit.c new file mode 100644 index 0000000..ffe349e --- /dev/null +++ b/compat/dbminit.c @@ -0,0 +1,115 @@ +/* dbminit.c - Open the file for dbm operations. This looks like the + DBM interface. */ + +/* This file is part of GDBM, the GNU data base manager. + Copyright (C) 1990, 1991, 1993, 2007 Free Software Foundation, Inc. + + 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 3, 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, write to the Free Software Foundation, + Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */ + +/* Include system configuration before all else. */ +#include "autoconf.h" + +#include "gdbmdefs.h" +#include "gdbmerrno.h" +#include "extern.h" + +/* Initialize dbm system. FILE is a pointer to the file name. In + standard dbm, the database is found in files called FILE.pag and + FILE.dir. To make gdbm compatable with dbm using the dbminit call, + the same file names are used. Specifically, dbminit will use the file + name FILE.pag in its call to gdbm open. If the file (FILE.pag) has a + size of zero bytes, a file initialization procedure is performed, + setting up the initial structure in the file. Any error detected will + cause a return value of -1. No errors cause the return value of 0. + NOTE: file.dir will be linked to file.pag. */ + +int +dbminit (char *file) +{ + char* pag_file; /* Used to construct "file.pag". */ + char* dir_file; /* Used to construct "file.dir". */ + struct stat dir_stat; /* Stat information for "file.dir". */ + int ret; + + + ret = 0; /* Default return value. */ + + /* Prepare the correct names of "file.pag" and "file.dir". */ + pag_file = (char *) malloc (strlen (file)+5); + dir_file = (char *) malloc (strlen (file)+5); + if ((pag_file == NULL) || (dir_file == NULL)) + { + gdbm_errno = GDBM_MALLOC_ERROR; /* For the hell of it. */ + return -1; + } + + strcpy (pag_file, file); + strcat (pag_file, ".pag"); + strcpy (dir_file, file); + strcat (dir_file, ".dir"); + + if (_gdbm_file != NULL) + gdbm_close (_gdbm_file); + + /* Try to open the file as a writer. DBM never created a file. */ + _gdbm_file = gdbm_open (pag_file, 0, GDBM_WRITER, 0, NULL); + + /* If it was not opened, try opening it as a reader. */ + if (_gdbm_file == NULL) + { + _gdbm_file = gdbm_open (pag_file, 0, GDBM_READER, 0, NULL); + + /* Did we successfully open the file? */ + if (_gdbm_file == NULL) + { + gdbm_errno = GDBM_FILE_OPEN_ERROR; + ret = -1; + goto done; + } + } + + /* If the database is new, link "file.dir" to "file.pag". This is done + so the time stamp on both files is the same. */ + if (stat (dir_file, &dir_stat) == 0) + { + if (dir_stat.st_size == 0) + if (unlink (dir_file) != 0 || link (pag_file, dir_file) != 0) + { + gdbm_errno = GDBM_FILE_OPEN_ERROR; + gdbm_close (_gdbm_file); + ret = -1; + goto done; + } + } + else + { + /* Since we can't stat it, we assume it is not there and try + to link the dir_file to the pag_file. */ + if (link (pag_file, dir_file) != 0) + { + gdbm_errno = GDBM_FILE_OPEN_ERROR; + gdbm_close (_gdbm_file); + ret = -1; + goto done; + } + } + + ret = 0; + +done: + free (dir_file); + free (pag_file); + return ret; +} |