=====unix Keywords===== ====PATH==== ===Definition=== PATH is an environmental variable that specifies a set of directories where executable programs are located. ===Demonstration=== lab46:~$export PATH=$PATH:/home/jdavis34/src/unix ==== Daemons==== ===Definition=== A daemon is a computer program that runs in the background as a process, instead of running in the foreground. Rather than being directly controlled by the user. Often these are used to start processes at a particular time, and or to maintain certain processes are always running. ====Wild Cards==== ===Definition=== Various tools that are very powerful in the land of UNIX. These enable a user to control the output of commands without having to specify the exact context of the name of a file. * zero or more of β€œany” character ? used to represent one of "any" character \ will ignore such things as space if the variable name isn't one string. ” ” (or ' ') quote the enclosed characters [ ] character class - match any of the enclosed characters. [^ ] inverted character class - do not match any of the enclosed characters. ====who==== ===Definition=== who - will print a list of all the current users logged in to a specific system. ===Demonstration=== jdavis34@lab46:~/src/cprog$ who NAME LINE TIME IDLE PID COMMENT jjohns43 + pts/24 2012-01-23 12:18 old 701 (cpe-74-65-82-173:S.0) skinney1 + pts/35 2012-03-16 10:15 20:26 27443 (65-124-85-125.dia.static.qwest.net) mfaucet2 + pts/65 2012-03-09 17:09 old 28217 (55:S.0) thakes3 + pts/68 2012-03-16 19:16 00:01 17986 (cpe-69-207-208-154:S.0) jdavis34 + pts/22 2012-03-06 12:57 00:18 2741 (cpe-69-205-141-69:S.0) thakes3 + pts/76 2012-03-16 15:41 00:02 6590 (cpe-69-207-208-154:S.2) thakes3 + pts/101 2012-03-16 20:32 00:01 19641 (cpe-69-207-208-154:S.1) jjohns43 + pts/82 2012-02-27 11:03 old 26118 (cpe-74-65-82-173:S.0) ====cron/crontab==== ===Definition=== This could be tied to daemon, but is the means of setting a daemon in the system. It is a time based job scheduler used to run periodically at certain times or dates. often used to automate system processes. ===Demonstration=== lab46:~$ cd src lab46:~/src$ gcc -o hello hello.c lab46:~/src$ ./hello Hello, World! lab46:~/src$ ====at/atrm==== ===Definition=== (at) is a powerful tool also used to schedule task, but for a single time occurrence. atrm is used to remove specific jobs, which can be done by following the command with the jobs PID number. ===Demonstration=== lab46:~$ cd src lab46:~/src$ gcc -o hello hello.c lab46:~/src$ ./hello Hello, World! lab46:~/src$ ====ps==== ===Definition=== ps gives a snapshot of the current processes. ===Demonstration=== jdavis34@lab46:~/src/cprog$ ps USER PID %CPU %MEM VSZ RSS TTY STAT START TIME COMMAND jdavis34 2741 0.0 0.1 13660 1916 pts/22 SNs Mar06 0:00 /bin/bash jdavis34 7001 0.0 0.1 13676 2028 pts/49 SNs Mar16 0:00 /bin/bash jdavis34 7004 0.0 0.1 13676 2032 pts/90 SNs Mar16 0:00 /bin/bash jdavis34 12154 0.0 0.3 42844 5376 pts/22 SN+ Mar10 1:04 irssi jdavis34 20760 0.0 0.8 54232 13632 pts/49 SN+ Mar16 0:00 gdb bignum jdavis34 29021 0.0 0.1 13636 1964 pts/8 SNs 08:48 0:00 -bash jdavis34 29024 0.0 0.1 61848 2352 pts/8 SN+ 08:48 0:00 screen -r jdavis34 29203 0.0 0.0 8588 988 pts/90 RN+ 09:46 0:00 ps u ====kill==== ===Definition=== kill is a very powerful command with a huge list of arguments that follow it, generally used to kill a process. ===Demonstration=== Refer to the previous word for seeing what process was killed. The argument -9 is OP... jdavis34@lab46:~/src/cprog$ kill -9 20760 jdavis34@lab46:~/src/cprog$ =====unix Objective===== ====unix Objective==== State the course objective ===Definition=== In your own words, define what that objective entails. ===Method=== State the method you will use for measuring successful academic/intellectual achievement of this objective. ===Measurement=== Follow your method and obtain a measurement. Document the results here. ===Analysis=== Reflect upon your results of the measurement to ascertain your achievement of the particular course objective. * How did you do? * Is there room for improvement? * Could the measurement process be enhanced to be more effective? * Do you think this enhancement would be efficient to employ? * Could the course objective be altered to be more applicable? How would you alter it?