Alters the Trusted Computing Base (TCB) status of a file.
#include <sys/tcb.h>
int tcb (Path, Flag) char *Path; int Flag;
The tcb subroutine provides a mechanism to query or set the TCB attributes of a file.
This subroutine is not safe for use with multiple threads. To call this subroutine from a threaded application, enclose the call with the _libs_rmutex lock. See "Making a Subroutine Safe for Multiple Threads" in AIX Version 4.3 General Programming Concepts: Writing and Debugging Programs for more information about this lock.
Upon successful completion, the tcb subroutine returns a value of 0 if the Flags parameter is either TCB_ON or TCB_OFF. If the Flags parameter is TCB_QUERY, the current status is returned. If the tcb subroutine fails, a value of -1 is returned and the errno global variable is set to indicate the error.
The tcb subroutine fails if one of the following is true:
| EINVAL | The Flags parameter is not one of TCB_ON, TCB_OFF, or TCB_QUERY. |
| EPERM | Not authorized to perform this operation. |
| ENOENT | The file specified by the Path parameter does not exist. |
| EROFS | The file system is read-only. |
| EBUSY | The file specified by the Path parameter is currently open for writing. |
| EACCES | Access permission is denied for the file specified by the Path parameter. |
Access Control: The calling process must have search permission for the object named by the Path parameter. Only the root user can set the tcb attributes of a file.
This subroutine is part of Base Operating System (BOS) Runtime.
The chmod or fchmod subroutine, statx, stat, lstat, fstatx, fstat, fullstat, or ffullstat subroutine.
The chmod command.
List of Security and Auditing Subroutines, Subroutines Overview in AIX Version 4.3 General Programming Concepts: Writing and Debugging Programs.