10 qlx02vprocess, Courseware, IBM Linux Advanced career education, Linux Power User, Visuals
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//-->Unit 10Working with ProcessesObjectivesAfter completing this unit, you should be able to:Define a Linux processDescribe the relationship between parent and childprocessesExplain the purpose of a shellStart foreground and background processesExplain the concept of signals and use them to terminateprocessesExplain the concept of priorities and manage themWhat is a Process?A program is an executable fileA process is a program which is being executedEach process has its own environment:process environmentProgram nameInternal dataOpen FilesCurrent Directoryadditional parametersUser and Group IDProcess ID (PID)Parent PID (PPID)Program variablesTo see the PID of your current shell process type:$ echo $$Starting and Stopping a ProcessAll processes are started by other processesParent/Child relationship$ ls -lbashfork()exec()ls -lexit()A process can be terminated because of tworeasons:The process terminates itself when doneThe process is terminated by a signal from anotherprocessLogin Process EnvironmentLinux SystemLogin:login:password:$/sbin/mingetty...forks /bin/bash-bash (login shell)EnvironmentProgramUIDGIDopen filesPID-bash503 (john)100 (users)/dev/tty1201
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