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/*
* db_ndbm.c: low level ndbm interface routines for man.
*
* Copyright (C) 1994, 1995 Graeme W. Wilford. (Wilf.)
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library 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
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*
* Mon Aug 8 20:35:30 BST 1994 Wilf. (G.Wilford@ee.surrey.ac.uk)
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif /* HAVE_CONFIG_H */
#ifdef NDBM
#include <stdlib.h>
#include <stdio.h>
#include <sys/file.h> /* for flock() */
#include <sys/types.h> /* for open() */
#include <sys/stat.h>
#if HAVE_FCNTL_H
# include <fcntl.h>
#endif
#include <unistd.h>
#include "stat-time.h"
#include "timespec.h"
#include "xvasprintf.h"
#include "manconfig.h"
#include "mydbm.h"
#include "db_storage.h"
/* release the lock and close the database */
int ndbm_flclose (DBM *db)
{
flock (dbm_dirfno (db), LOCK_UN);
dbm_close (db);
return 0;
}
/* open a ndbm type database, with file locking. */
DBM* ndbm_flopen (char *filename, int flags, int mode)
{
DBM *db;
int lock_op;
int lock_failed;
if (flags & ~O_RDONLY) {
/* flags includes O_RDWR or O_WRONLY, need an exclusive lock */
lock_op = LOCK_EX | LOCK_NB;
} else {
lock_op = LOCK_SH | LOCK_NB;
}
if (flags & O_TRUNC) {
/* opening the db is destructive, need to lock first */
char *dir_fname;
int dir_fd;
db = NULL;
lock_failed = 1;
dir_fname = xasprintf ("%s.dir", filename);
dir_fd = open (dir_fname, flags & ~O_TRUNC, mode);
free (dir_fname);
if (dir_fd != -1) {
if (!(lock_failed = flock (dir_fd, lock_op)))
db = dbm_open (filename, flags, mode);
close (dir_fd);
}
} else {
db = dbm_open (filename, flags, mode);
if (db)
lock_failed = flock (dbm_dirfno (db), lock_op);
}
if (!db)
return NULL;
if (lock_failed) {
gripe_lock (filename);
dbm_close (db);
return NULL;
}
return db;
}
struct timespec ndbm_get_time (DBM *db)
{
struct stat st;
if (fstat (dbm_dirfno (db), &st) < 0) {
struct timespec t;
t.tv_sec = -1;
t.tv_nsec = -1;
return t;
}
return get_stat_mtime (&st);
}
void ndbm_set_time (DBM *db, const struct timespec time)
{
struct timespec times[2];
times[0] = time;
times[1] = time;
futimens (dbm_dirfno (db), times);
}
#endif /* NDBM */
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