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/* $Id: lockfile.c 6020 2002-12-20 00:19:58Z rra $
**
** Lock a file or a range in a file.
**
** Provides inn_lock_file and inn_lock_range functions to lock or unlock a
** file or ranges within a file with a more convenient syntax than fcntl.
** Assume that fcntl is available.
*/
#include "config.h"
#include "clibrary.h"
#include <errno.h>
#include <fcntl.h>
#include "libinn.h"
bool
inn_lock_file(int fd, enum inn_locktype type, bool block)
{
return inn_lock_range(fd, type, block, 0, 0);
}
bool
inn_lock_range(int fd, enum inn_locktype type, bool block, off_t offset,
off_t size)
{
struct flock fl;
int status;
switch (type) {
case INN_LOCK_READ: fl.l_type = F_RDLCK; break;
case INN_LOCK_WRITE: fl.l_type = F_WRLCK; break;
default:
case INN_LOCK_UNLOCK: fl.l_type = F_UNLCK; break;
}
do {
fl.l_whence = SEEK_SET;
fl.l_start = offset;
fl.l_len = size;
status = fcntl(fd, block ? F_SETLKW : F_SETLK, &fl);
} while (status == -1 && errno == EINTR);
return (status != -1);
}
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