Lock a file (advisory lock).
Source position: unix.pp line 140
| function fpFlock( | 
| var T: text; | 
| mode: cint | 
| ):cint; | 
| var F: file; | 
| mode: cint | 
| ):cint; | 
| fd: cint; | 
| mode: cint | 
| ):cint; | 
FpFLock implements file locking. it sets or removes a lock on the file F. F can be of type Text or File, or it can be a Linux file descriptor (a longint) Mode can be one of the following constants :
The function returns zero if successful, a nonzero return value indicates an error.
Extended error information is returned by the FpGetErrno function:
| 
 | File control operations. | |
| 
 | Synchronize file's kernel data with disk. |