Introduction to Unix Week 3

Transcription

1 Week 3 cat [file ] Display contents of files cat sample.file This is a sample file that i'll use to demo how the pr command is used. The pr command is useful in formatting various types of text files. head [-n count ] [file ] Display the beginning of a file Default count is 10 head n 3.bash_profile #.bash_profile # Get the aliases and functions head -3.bash_profile #.bash_profile # Get the aliases and functions Page 1

2 tail [-n count] [file ] Display the end of a file Default count is 10 tail n 2.bash_profile alias c=clear who q tail 2.bash_profile alias c=clear who q } more [file ] Display files one page at a time more largefile This is a sample file that i'll use to demo how the pr command is used. The pr command is useful in formatting various types of text files. --More--(16%) Spacebar (next page) b (back 1 page) Enter Key (next line) q (Quit & return to unix) /string (search for string) :n (next file) :p (previous file) } pr [file ] Format & Display Files to the Screen pr sample.file :07 sample.file Page 1 This is a sample file that i'll use to demo how the pr command is used. The pr command is useful in formatting various types of text files. Page 2

3 } pr [file ] -d Double Space Output -n Number Lines pr -d sample.file :07 sample.file Page 1 This is a sample file that i'll use to demo how the pr command is used. pr -n sample.file The pr command is useful in formatting :07 sample.file Page 1 various types of text files. 1 This is a sample file that i'll use to demo how the 2 pr command is used. 3 The pr command is useful in formatting 4 various types of text files. } lp [file ] Send Files to a Unix Printer No Formatting (page numbers, etc.) lp prog1 mbox pr sample.file Ideal solution would be to combine the lp & pr to achieve formatted printed output :07 sample.file Page 1 This is a sample file that i'll use to demo how the pr command is used.... } Output Normally Displayed to the Screen is Redirected and Becomes the Input to Another Command pr prog1 lp Page 3

4 } The Output of One Command can be used as the Input to Another pr prog1 lp Command that generates screen output Command Command Command that requires input Command Command Command... ls pr lp Directory Listing Formatted Using pr, Printed on Paper Page 4

5 } Output Normally Displayed to the Screen Can Be Redirected to a File pr prog1 > prog1.pr Note: Nothing is displayed to the screen The file prog1.pr contains the output of the pr command } Redirecting Output The Output of Command can be saved to a File Command that generates screen output pr prog1 > prog1.pr Command > File Caution: Output File will be erased if it already exists. File used to capture (save) screen output Page 5

6 } Redirecting Output The output of command is appended to the end of a file Command that generates screen output date >> prog1.pr Command >> File If the file does not exist it will be created File used to capture (save) screen output } wc [file ] Word Count -l Display Number of Lines -w Display Number of Words -c Display Number of Characters wc mbox mbox wc mbox ls.file mbox ls.file total } sort [file ] Sort the Contents of a File -f Ignore Case -n Sort Numbers Based on Value -r Reverse Order cat words sand box zoo xray sam jones sort words box jones sam sand xray zoo Page 6

7 cat file > file echo I am chocolate > chocolate echo I am peanut butter > peanut_butter cat chocolate peanut_butter I am chocolate I am peanut butter cat chocolate peanut_butter > reeses cat reeses I am chocolate I am peanut butter 1 pr data > data.pr lp data.pr pr data lp 2 cal > year 3 ls -l data > stuff 4 pr data > lp 5 cat text let > mesg 6 pr f1 f2 > f1 2 pr f1 and f2, redirect to f1 1 Create the file f1 Erases f1 if it already exists Page 7

8 } grep string [file ] Find a char string contained in a file Global Regular Expression Processor cat data this is a sample file that we'll use to test the unix grep command. unix commands can some interesting names grep unix data unix grep command. unix commands can some interesting } grep string [file ] grep unix data wp data:unix grep command. data:unix commands can some interesting wp:created with the unix command vi. wp:this unix editor can grep "unix comm" data wp data:unix commands can some interesting wp:created with the unix command vi. } \ ' " ` * ;? { } ( ) [ ] ~! < > & # space Characters with special meaning to the shell Space Argument Delimiter # Comment Line ; Command Separator ~ Home directory Command Redirection > Output File Redirection < Input File Redirection *? [] File matching \ ' " Escape meta characters ` Inline execution Page 8

9 * Match zero or more characters ls a* more data* ls a*z cp a* data ls a*9*z rm junk*? Match any single character ls a? more data? ls a?z cp a? data ls a?? rm junk? [ ] Match any single character in the list ls a[abc] aa, ab, ac ls a[abc0-9]z aaz, a9z, acz ls a[adza-z] aa, az, aa Page 9

10 } Combining Meta Characters ls a?[123] aa1, au3, az2 ls data*[89][12] data81, data91, datazz82 ls mail?[xy]* mailxx1234, mail8y } Display a Line of asterisks echo *** FAIL! } Backslash (\) Disables One Meta Character echo \*\*\* *** Page 10

11 } Enclose in single quotes (') Disables all Meta Characters in between the quotes echo '***' *** } Enclose in double quotes (") Disables Meta Characters in between the quotes Except: Backslash, Dollar Sign and Backtick (\, and `) remain active. echo My \HOME is HOME My HOME is /home/rdefe echo "Today is `date`" Today is Mon Jan 22 22:04:46 EST 1996 echo "Today's date is: `date +%B\ %e,\ %Y`" Today's date is: March 12, 2016 } Homework Assignment } Take Home Quiz Page 11