snap – process snapshots
Process snapshots are used to save a process image for debugging on another machine or at another time. They are like old Unix core dumps but can hold multiple process images and are smaller.
The first line of a snapshot begins with the prefix “process snapshot” and often contains other information as well, such as creation time, user name, system name, cpu type, and kernel type. This information is intended for humans, not programs. Programs reading snapshots should only check that this line begins with the specified prefix.
Throughout the rest of the snapshot, decimal strings are always right-justified, blank-padded to at least 11 characters, and followed by a single space character.
The rest of the snapshot is one or more records, each of which begins with a one-line header. This header is a decimal process id followed by an identification string, which denotes the type of data in the record.
Records of type
The format of the
It is not guaranteed that any of the sections described above be in a process snapshot, although the snapshot quickly becomes useless when too much is missing.
Memory and text images may be incomplete. The memory or text file for a given process may be split across multiple disjoint sections in the snapshot.