CPSC 1280 Lecture Notes - Lecture 25: Background Process, Shell Script, Sighup
19 Feb 2017
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Road map: signals, exit code, subshell, job control. 22 hangup modem connection is broken; restarts a demon terminal interrupt user hits interrupt key quit from terminal - process produce a core dump file. Surest kill can"t be trapped default termination signal used by kill command suspends process - user hits [ctrl-z] child terminates kernel sends signal to parent suspends process background process attempts to read. Sigttou suspends process background process attempts to write. Kill a process: the kill command, internal command (/bin/kill if the shell lacks kill capability, usually with the intention of killing the process, by default sends sigterm (15) signal, usage, $ kill options pid(s) Example: $ kill 105, $ kill -s term 105, kill parent to kill all its children, exception with nohup command, init acquires their parentage. Kill: even though kill is normally used to kill a process, the term is a misnomer.
