The VI Editor, one of the greats, nano on steroids. VI Editor is a text editor with much more to bring to the table, between its tools and its unique style of dealing with the editing of text. It is in simple a text editor with extras.
To demonstrate the VI Editor, I will show a fully functional VI Interface with the extra of line numbers and syntax highlighting:
lab46:~$ install vim lab46:~$ vi test.c
1 #include <stdio.h> 2 #include <stdlib.h> 3 #include <stdbool.h> 4 5 int main(int argc, char **argv){ 6 int input; 7 bool check = false; 8 unsigned char i; 9 while (check == false){ 10 printf("Enter a value (0-4):"); 11 scanf("%d", &input); 12 if (input > 4 || input < 0){ 13 printf("You have entered an incorrect value.\n"); 14 check = false; 15 }else{ 16 for (i = 0; i < argc; i++){ 17 printf("argv[%hhu][%hhu]: %c\n", i, input, *(*(argv+i)+input)); 18 } 19 check = true; 20 } 21 } 22 return(0); 23 } 24
Local host is the computer you are working on, it is the web address of the computer you are working on, it is a loopback in networking. Although local host can take many forms, it is simply your computer's identifier.
If you were to type: http://localhost into your web browser, you would be returned with the local web service of your computer.
Remote hosts are computers that are not locally accessed, rather are at a distance from where you are. They are still accessible and you can retrieve data from them, but they are a distance away.
Remote hosts are usually thought of as network servers or just servers in general, where you would ssh into. An example of this to me would be:
lab46:~$ ssh root@vm31.student.lab
The way I believe a home directory works, is that it can be a supply source for many users, who can separately have their own subsystems of directories but all refer back to a starting point. Even though it can be used by many, each is very different in its own right, different files and directories based on the user.
This demonstration will show a Home directory with many users.
lab46:~$ cd /home lab46:/home$ ls ab000126 bdevaul cmcavoy drobie2 haas jhall40 jvanott1 lmcconn4 nrounds rrichar8 tdoud abranne1 bewanyk cmille37 ds000461 hansolo jhammo13 jwalrat2 lmerril3 nsano rsantia4 tedmist1 abrunda1 bfarr2 cmulkeri ds003420 hclark9 jj001572 jwhitak3 mallis3 nsr1 rshaw8 tfitch1 acanfie1 bh011695 cnicho13 dschoeff hepingerjj jjansen4 jwilli30 mbeschle nvergaso rthatch2 tgalpin2 acarpen5 bherrin2 comeaubk dshadeck hhabelt jjohns43 jwilso39 mbonacke nwebb ryoung12 thakes3 acrocker bhuffner cpainter dsherbur hps1 jjohnst8 jwood36 mbrigham oppenheim sblake3 thatcher adexter bkenne11 critten1 dshreve hramsey jkingsle jzimmer5 mbw6 pclose sc000826 tjohns22 adilaur1 bkrishe3 csit2310 dstorm3 hshaikh jkremer1 kamakazi mcantin3 pcremidi sclayton tkane1 aettenb3 bnichol7 csleve dtalvi hwarren1 jlantz4 kbell1 mclark35 pdowd sedward9 tkiser afassett bobpauljr cspenc12 dtaylo15 ian jlazaar kboe mcooper6 plindsa1 sjankows tl009536 agardin4 bort csteve16 dtennent imaye jluedema kc017344 mdecker3 pm004968 sjelliso tmizerak ahazen bowlett1 cwagner1 dtravis4 jandrew9 jm010967 kcard2 mdittler pmcconn1 skinney1 tmong ajernig2 brian cwilder1 dwalrat1 javery9 jmanley3 kcaton mearley1 qclark smacombe tp001498 ajoensen brobbin4 cwoolhis dwells6 jbaez jmille59 kcook6 mfailing radams4 smalik2 triley2 alius bstoll darduini dwrigh18 jbamper jmitch22 kcornel6 mfaucet2 rberry3 smatusic ts004985 amorich1 btaber2 dates eberdani jbarne13 jmunson kdenson mgough rbuchan7 smclaug3 vcordes1 anarde bwheat db010905 efarley jbesecke jmyers7 kgarrah1 mguthri2 rcaccia1 smd15 wag2 anorthr3 bwilso23 dchilso3 egarner jblaha jo009612 kgaylord mhenry9 redsting3d smilfor3 wedge anowaczy bwilson3 dcicora1 egleason jblanch1 jpettie kinney mkellogg reedkl spetka wezlbot ap016986 cacquah ddragoo emorris4 jbrant jphill17 kkrauss1 mkelsey1 rfinney2 spline wfischba appelthp cas21 dfoulk1 en007636 jbrizzee jr018429 klynch3 mmatt rglover squires wknowle1 aradka caustin8 dgirard3 erava jburlin1 jrampul1 kpryslop mowens3 rhender3 squirrel wroos aromero ccaccia dh002925 erebus jc006215 jsabin1 kreed11 mp018526 rhensen srk3 ystebbin as012495 ccarpe10 dh018304 eryan3 jcardina jschira1 kscorza mpage9 rj005436 srog zlittle ascolaro cchandan dherman3 estead jcavalu3 jshare1 ksisti2 mpaul6 rjohns41 ssmith85 zmccann asmedley ccranda2 dlalond1 eveilleu jcosgro4 jshort6 kwalker2 mpresto4 rkapela sswimle1 zward asowers cderick dm005264 ewester1 jdavis34 jsmit176 lburzyns mshort3 rlott strego astrupp cdewert dmagee3 ezajicek jdawson2 jstrong4 lcrowley mtaft4 rm002127 svrabel atoby cforman dmay5 fclark1 jdrew jsulli34 ld010818 mwagner3 rmatsch swarren4 atownsle cgoodwin dmckinn2 gc007950 jeisele jsulliv3 leckley mwarne11 rmoses sweller5 atreat2 ckelce dmurph14 gcalkin3 jellis15 jt011443 lgottsha mwitter3 rnewman swilli31 awalke18 ckuehner dpadget8 ggamarra jferrito jtongue2 lh000592 nandre rosenbll syang bblack1 clawren2 dparson3 gr015546 jfrail jtreacy lhubbar3 nbaird rpage3 synack bboaz cmace1 dpotter8 groush1 jfurter2 jtripp llaughl3 nblancha rpetzke1 ta018998 bbrown17 cmahler dprutsm2 gsnyder jh001093 jv001406 lleber ngraham2 rraplee tcolli12 lab46:/home$
A current working directory to me is a folder a person has created and uses for files depending on the purpose of the folder and can access with cd issued commands and can change permissions on files inside of the folder.
Here is a current working directory of my own:
lab46:~$ cd src/cprog lab46:~/src/cprog$ ls bigNum cipher.c file ftypes functions.c icprog linkedlist.h out.txt prog1x5.c prog4 prog5 prog6.c prog8 prog9 test.c var2 bigNum.c cipher.txt file.c ftypes.c hint1 icprog.c message.in plain.txt prog3 prog4.c prog5.c prog7 prog8.c prog9.c var1 var2.c cipher decipher.txt file.txt functions hint1.c key.txt nofile.txt prog1x5 prog3.c prog4.c.save prog6 prog7.c prog8.c.save test var1.c lab46:~/src/cprog$ ls -l total 268 -rwxr-xr-x 1 jpettie lab46 9521 Mar 1 21:05 bigNum -rw-r--r-- 1 jpettie lab46 1832 Mar 1 21:05 bigNum.c -rwxr-xr-x 1 jpettie lab46 9452 Feb 28 14:20 cipher -rw-r--r-- 1 jpettie lab46 2323 Mar 1 19:55 cipher.c -rw-r--r-- 1 jpettie lab46 34 Feb 24 20:04 cipher.txt -rw-r--r-- 1 jpettie lab46 34 Feb 28 17:44 decipher.txt -rwxr-xr-x 1 jpettie lab46 7481 Feb 7 16:48 file -rw-r--r-- 1 jpettie lab46 372 Feb 7 16:48 file.c -rw-r--r-- 1 jpettie lab46 15 Feb 7 16:45 file.txt -rwxr-xr-x 1 jpettie lab46 8275 Mar 1 15:18 ftypes -rw-r--r-- 1 jpettie lab46 1007 Mar 1 16:10 ftypes.c -rwxr-xr-x 1 jpettie lab46 8058 Feb 24 15:09 functions -rw-r--r-- 1 jpettie lab46 1061 Feb 24 11:55 functions.c -rwxr-xr-x 1 jpettie lab46 7754 Feb 27 11:58 hint1 -rw-r--r-- 1 jpettie lab46 692 Feb 28 10:43 hint1.c -rwxr-xr-x 1 jpettie lab46 7136 Feb 16 16:14 icprog -rw-r--r-- 1 jpettie lab46 481 Feb 16 16:30 icprog.c -rw-r--r-- 1 jpettie lab46 19 Feb 24 21:48 key.txt -rw-r--r-- 1 jpettie lab46 509 Mar 1 21:01 linkedlist.h -rw-r--r-- 1 jpettie lab46 42 Feb 27 09:57 message.in -rw-r--r-- 1 jpettie lab46 0 Mar 1 23:42 nofile.txt -rw-r--r-- 1 jpettie lab46 14 Feb 7 16:48 out.txt -rw-r--r-- 1 jpettie lab46 0 Mar 1 23:42 plain.txt -rwxr-xr-x 1 jpettie lab46 11673 Mar 1 23:42 prog1x5 -rw-r--r-- 1 jpettie lab46 1165 Mar 1 23:42 prog1x5.c -rwxr-xr-x 1 jpettie lab46 6771 Jan 31 15:07 prog3 -rw-r--r-- 1 jpettie lab46 267 Jan 31 15:07 prog3.c -rwxr-xr-x 1 jpettie lab46 7031 Jan 31 16:02 prog4 -rw-r--r-- 1 jpettie lab46 452 Jan 31 16:02 prog4.c -rw-r--r-- 1 jpettie lab46 300 Feb 14 12:17 prog4.c.save -rwxr-xr-x 1 jpettie lab46 7039 Jan 31 16:36 prog5 -rw-r--r-- 1 jpettie lab46 246 Feb 2 11:07 prog5.c -rwxr-xr-x 1 jpettie lab46 7738 Feb 2 15:42 prog6 -rw-r--r-- 1 jpettie lab46 589 Feb 16 16:58 prog6.c -rwxr-xr-x 1 jpettie lab46 7453 Feb 7 16:24 prog7 -rw-r--r-- 1 jpettie lab46 338 Feb 7 16:24 prog7.c -rwxr-xr-x 1 jpettie lab46 7632 Feb 14 14:31 prog8 -rw-r--r-- 1 jpettie lab46 458 Feb 28 10:56 prog8.c -rw-r--r-- 1 jpettie lab46 459 Feb 14 12:17 prog8.c.save -rwxr-xr-x 1 jpettie lab46 6965 Feb 14 15:40 prog9 -rw-r--r-- 1 jpettie lab46 384 Feb 28 11:06 prog9.c -rwxr-xr-x 1 jpettie lab46 7465 Feb 24 21:46 test -rw-r--r-- 1 jpettie lab46 484 Feb 24 21:46 test.c -rwxr-xr-x 1 jpettie lab46 6786 Jan 26 15:49 var1 -rw-r--r-- 1 jpettie lab46 305 Jan 26 15:49 var1.c -rwxr-xr-x 1 jpettie lab46 6794 Jan 26 16:41 var2 -rw-r--r-- 1 jpettie lab46 256 Jan 26 16:41 var2.c lab46:~/src/cprog$
The way I think of Text Processing is a technique or device used to edit, and save text into files or from files but can also be used just on plain text as well to change it (for example: to change the color of text).
A tool used to process text I've used in the past and would be a good demonstration would be “nano”
lab46:~/src/cprog$ nano prog3.c
#include <stdio.h> int main(){ int v = 17; int *p1 = NULL; printf("v is %u \n", v); p1 = &v; printf("*p1 is %u\n", *p1); *p1 = 53; printf("v is %u\n", v); printf("*p1 is %u\n", *p1); v = 7; printf("v is %u\n", v); printf("p1 is %u\n", *p1); return(0); }
To me, Job Control is just another way of saying multitasking, but to multitask efficiently. To control the outcome and resources needed by each job to complete its task and to give the right results along with being able to run them both at the same time.
An example of Job Control to me, is using more than one windows in a screen session and having one be a tail to log files, and the other to run a bnetd file for a pvpgn server.
tail: invalid option -- * jpettie@lab46:~$ ssh root@vm31.student.lab Try `tail --help' for more information. Warning: Permanently added 'vm31.student.lab,10.80.3.31' (RSA) to the list of known hosts. vm31:/usr/local/var# tail --help root@vm31.student.lab's password: Usage: tail [OPTION]... [FILE]... Linux vm31 2.6.26-2-xen-686 #1 SMP Wed Sep 21 09:56:47 UTC 2011 i686 Print the last 10 lines of each FILE to standard output. With more than one FILE, precede each with a header giving the file name. The programs included with the Debian GNU/Linux system are free software; With no FILE, or when FILE is -, read standard input. the exact distribution terms for each program are described in the individual files in /usr/share/doc/*/copyright. Mandatory arguments to long options are mandatory for short options too. --retry keep trying to open a file even if it is Debian GNU/Linux comes with ABSOLUTELY NO WARRANTY, to the extent inaccessible when tail starts or if it becomes permitted by applicable law. inaccessible later; useful when following by name, Last login: Sat Mar 3 02:57:33 2012 from lab46.offbyone.lan i.e., with --follow=name vm31:~# cd /usr/local -c, --bytes=N output the last N bytes; alternatively, use +N to vm31:/usr/local# cd sbin output bytes starting with the Nth of each file vm31:/usr/local/sbin# ls -f, --follow[={name|descriptor}] bnetd bntrackd d2cs d2dbs output appended data as the file grows; vm31:/usr/local/sbin# -f, --follow, and --follow=descriptor are equivalent -F same as --follow=name --retry -n, --lines=N output the last N lines, instead of the last 10; or use +N to output lines starting with the Nth --max-unchanged-stats=N with --follow=name, reopen a FILE which has not changed size after N (default 5) iterations to see if it has been unlinked or renamed (this is the usual case of rotated log files) --pid=PID with -f, terminate after process ID, PID dies -q, --quiet, --silent never output headers giving file names -s, --sleep-interval=S with -f, sleep for approximately S seconds (default 1.0) between iterations. -v, --verbose always output headers giving file names --help display this help and exit --version output version information and exit If the first character of N (the number of bytes or lines) is a `+', print beginning with the Nth item from the start of each file, otherwise, print the last N items in the file. N may have a multiplier suffix: b 512, kB 1000, K 1024, MB 1000*1000, M 1024*1024, GB 1000*1000*1000, G 1024*1024*1024, and so on for T, P, E, Z, Y. With --follow (-f), tail defaults to following the file descriptor, which means that even if a tail'ed file is renamed, tail will continue to track its end. This default behavior is not desirable when you really want to track the actual name of the file, not the file descriptor (e.g., log rotation). Use --follow=name in that case. That causes tail to track the named file by reopening it periodically to see if it has been removed and recreated by some other program. Report bugs to <bug-coreutils@gnu.org>. vm31:/usr/local/var# tail -f .log tail: cannot open `.log' for reading: No such file or directory tail: no files remaining vm31:/usr/local/var# tail -f *.log Mar 01 23:43:34 [info ] channel_destroy: destroying channel "Emperor-2" Mar 01 23:43:34 [info ] channel_destroy: destroying channel "Red Alert 2-1" Mar 01 23:43:34 [info ] channel_destroy: destroying channel "Red Alert 2-2" Mar 01 23:43:34 [info ] channel_destroy: destroying channel "Nox Quest-1" Mar 01 23:43:34 [info ] channel_destroy: destroying channel "Yuri's Revenge-1" Mar 01 23:43:34 [info ] channel_destroy: destroying channel "Yuri's Revenge-2" Mar 01 23:43:34 [info ] channel_destroy: destroying channel "Lob 38 0" Mar 01 23:43:34 [info ] channel_destroy: destroying channel "Lob 39 0" Mar 01 23:43:34 [info ] channel_destroy: destroying channel "Lob 40 0" Mar 01 23:43:34 [info ] main: server has shut down
When I think of Regular Expressions, I tend to think of if statements, comparing two things and seeing if they match, depending on type of course.
Here is a while statement to show Regular Expressions:
while (check == false){ some sort of code to execute here }
Exposure to command-line tools and utilities
In my own thoughts, I would consider the completion of this objective as using tools such as vi to accomplish a task, or even produce a program in c.
The method I will use to show the completion of this objective is an example of vi editing of a program.
Here is an example of vi after adding line numbers and syntax highlighting:
1 #include <stdio.h> 2 #include <stdlib.h> 3 #include <stdbool.h> 4 5 int main(int argc, char **argv){ 6 int input; 7 bool check = false; 8 unsigned char i; 9 while (check == false){ 10 printf("Enter a value (0-4):"); 11 scanf("%d", &input); 12 if (input > 4 || input < 0){ 13 printf("You have entered an incorrect value.\n"); 14 check = false; 15 }else{ 16 for (i = 0; i < argc; i++){ 17 printf("argv[%hhu][%hhu]: %c\n", i, input, *(*(argv+i)+input)); 18 } 19 check = true; 20 } 21 } 22 return(0); 23 } 24
I believe I have showed use of a tool or utility from the command line. I think there is always room to grow, especially when you are running low on time and waited to long to complete your opus. The method seems pretty solid, it shows an example of a working tool. Employing this enhancement will work because the program will run. I believe the course objective is very vital and strong as it stands.