CPSC 1280 Lecture Notes - Lecture 24: Wcai, Passwd, Child Process
19 Feb 2017
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Document Summary
Road map: process, process cycle, process attribute, process permissions, process states. Process id: process is identified by a unique pid (process id, the ps command displays, processes, pids, the command associated with them, other process information. Ps option: -e option, all processes including user and system processes, -f option, to generate a full listing. Process attribute: not inherited by child, pid, ppid. Inherited by child: real uid and gid, effective uid and gid, current directory, file descriptors, umask value, environment variables. Environment variable: a local variable is not visible in child processes. $ : environment variable is visible in all child processes. 5: changes on child"s environment variable is not available in parent. Rwxr-xr-x 1 root root 22536 2011-07-27 15:30 /bin/cat. Process privileges: set user id & set group id permissions 3rd permission in the owner and group clusters resp. is set to s instead of x.
