One who watches or guards; specifically (Mil.), a soldier set to guard an army, camp, or other place, from surprise, to observe the approach of danger, and give notice of it; a sentry.
One or more members of a group of birds that are perched high above the rest of a group and seem to be watching for trouble. For example, crows are often seen sitting at the top of a tree and watching.
Sentinel is a 16m high sculpture by Tim Tolkien, installed upon a traffic island at the intersection of the Chester Road and the A47 Fort Parkway at the entrance to the Castle Vale estate in Birmingham, England.
Sentinel is a fast file scanner similar to Tripwire or Viper with built in authentication using the RIPEMD 160 bit MAC hashing function. It uses a single database similar to Tripwire, maintains file integrity using the RIPEMD algorithm and also produces secure, signed logfiles. Its main design goal is to detect intruders modifying files.
This is not only next milter implementation for Sendmail Milter API. This filter can satisfy more or less subtle requirements from unix system administrators who are using open source sendmail. Learn more on http://smfilter.sourceforge.net
an expression occurring in a Certificate validating an Inference Step identifying which primitive logical resources are permitted in justifying it; the unit of coherency in Proofs
In the context of searching in a data structure, a piece of data used to avoid an explicit test for a null pointer, the end of an array, etc., typically by setting its value to that of the looked-for data item.
A sentinel in computer science refers to a special type of object that represents the end of a data structure. Linked List data structures may use a sentinel object to indicate the end of a list. Similarly, a Tree data structure can use a sentinel to indicate a node has no children.