Coding Challenge: Build Your Own grep by John Crickett

Build Your Own grep

https://codingchallenges.fyi/challenges/challenge-grep/

Dependencies:

Picocli - https://picocli.info/

Usage

java -jar target/javagrep-1.0-SNAPSHOT.jar org.dojo.grep.Main "<pattern>" "<filename>"

<filename> is from target/test-classes/.

Features

Support an empty expression

Acceptance Criteria

Input:

java -jar target/javagrep-1.0-SNAPSHOT.jar org.dojo.grep.Main "" target/test-classes/essays/BFS1985.txt | diff target/test-classes/essays/BFS1985.txt -
java -jar target/javagrep-1.0-SNAPSHOT.jar org.dojo.grep.Main "" target/test-classes/rockbands.txt | diff target/test-classes/rockbands.txt -
java -jar target/javagrep-1.0-SNAPSHOT.jar org.dojo.grep.Main "" target/test-classes/symbols.txt | diff target/test-classes/symbols.txt -
java -jar target/javagrep-1.0-SNAPSHOT.jar org.dojo.grep.Main "" target/test-classes/artofwar.txt | diff target/test-classes/artofwar.txt -

Output:

Match One-Letter Pattern

Input:

java -jar target/javagrep-1.0-SNAPSHOT.jar org.dojo.grep.Main J target/test-classes/rockbands.txt

Output:

Judas Priest
Bon Jovi
Junkyard

Support recursively listing a directory

Input:

java -jar target/javagrep-1.0-SNAPSHOT.jar org.dojo.grep.Main --recursive Nirvana src/test/resources

Output:

rockbands.txt:Nirvana
essays/BFS1985.txt:Since Bruce Springsteen, Madonna, way before Nirvana
essays/BFS1985.txt:On the radio was Springsteen, Madonna, way before Nirvana
essays/BFS1985.txt:And bring back Springsteen, Madonna, way before Nirvana
essays/BFS1985.txt:Bruce Springsteen, Madonna, way before Nirvana

Input:

java -jar target/javagrep-1.0-SNAPSHOT.jar org.dojo.grep.Main --recursive heaven src/test/resources

Output:

essays/coffee.txt:And still a heaven of brass inflames the burning hours.
essays/coffee.txt:Spreading branches, nor lifts a lofty top to heaven;
essays/coffee.txt:That human laws were never made in heaven;
essays/coffee.txt:     heaven for Coffee, for see how many blessings are concentrated in
essays/coffee.txt:  Now mounted up to heaven again,
artofwar.txt:heaven, is it not right that those in authority should value and be
artofwar.txt:heaven.
artofwar.txt:skilled in attack flashes forth from the topmost heights of heaven [see
artofwar.txt:thereby succeed in winning, may be called a heaven-born captain.
artofwar.txt:and hammering on bronze vessels, until heaven and earth were convulsed
artofwar.txt:affairs of men, the seasons of heaven and the natural advantages of

Support bash compatible glob patterns

Input:

java -jar target/javagrep-1.0-SNAPSHOT.jar org.dojo.grep.Main biograph target/test-classes/{*,**/*}.txt

Output:

Ssu-ma Ch’ien gives the following biography of Sun Tzŭ: [1]
this chapter. But he proceeds to give a biography of his descendant,
biography were false and untrustworthy? The answer, I fear, must be in
Kung’s preface to his edition, and the biography of Sun Tzŭ from the
man, whose biography in the _San Kuo Chih_ reads like a romance. One of
48. A notable person in his day. His biography is given in the _San Kuo
[1] See Col. Henderson’s biography of Stonewall Jackson, 1902 ed., vol.
from. It is not given in the biography of Li Hsiung or that of his
English prose; Oliver Goldsmith; Boswell, the biographer; Burke, the
most delightful biography in all literature. Boswell's taste for
     dine here with Wilkie. In his "Autobiography," in the year 1808,
_biog._       "     biography
_Autobiography_, Haydon, _q._, 583

Support piping input from standard input

Input:

java -jar target/javagrep-1.0-SNAPSHOT.jar org.dojo.grep.Main --recursive Nirvana target/test-classes | java -jar target/javagrep-1.0-SNAPSHOT.jar org.dojo.grep.Main Madonna -

Output:

essays/BFS1985.txt:Since Bruce Springsteen, Madonna, way before Nirvana
essays/BFS1985.txt:On the radio was Springsteen, Madonna, way before Nirvana
essays/BFS1985.txt:And bring back Springsteen, Madonna, way before Nirvana
essays/BFS1985.txt:Bruce Springsteen, Madonna, way before Nirvana

Support inverse matching

Input:

java -jar target/javagrep-1.0-SNAPSHOT.jar org.dojo.grep.Main --recursive Nirvana target/test-classes | java -jar target/javagrep-1.0-SNAPSHOT.jar org.dojo.grep.Main -v Springsteen -

Output:

rockbands.txt:Nirvana

Input:

java -jar target/javagrep-1.0-SNAPSHOT.jar org.dojo.grep.Main --recursive Madonna target/test-classes | java -jar target/javagrep-1.0-SNAPSHOT.jar org.dojo.grep.Main -v radio -

Output:

essays/BFS1985.txt:Since Bruce Springsteen, Madonna, way before Nirvana
essays/BFS1985.txt:And bring back Springsteen, Madonna, way before Nirvana
essays/BFS1985.txt:Bruce Springsteen, Madonna, way before Nirvana

Support digit and word search patterns

Input:

java -jar target/javagrep-1.0-SNAPSHOT.jar org.dojo.grep.Main "\d" target/test-classes/essays/BFS1985.txt

Output:

Her dreams went out the door when she turned 24
There was U2 and Blondie, and music still on MTV
'Cause she's still preoccupied with 19, 19, 1985, 1985
There was U2 and Blondie, and music still on MTV
'Cause she's still preoccupied with 19, 19, 1985
There was U2 and Blondie, and music still on MTV
'Cause she's still preoccupied with 1985
There was U2 and Blondie, and music still on MTV
'Cause she's still preoccupied with 19, 19, 1985

Input:

java -jar target/javagrep-1.0-SNAPSHOT.jar org.dojo.grep.Main "\w" target/test-classes/essays/BFS1985.txt

Output:

Debbie just hit the wall, she never had it all
One Prozac a day, husband's a CPA
Her dreams went out the door when she turned 24
Only been with one man, what happened to her plan?
She was gonna be an actress, she was gonna be a star
She was gonna shake her ass on the hood of Whitesnake's car
Her yellow SUV is now the enemy
Looks at her average life, and nothing has been alright
Since Bruce Springsteen, Madonna, way before Nirvana
There was U2 and Blondie, and music still on MTV
Her two kids in high school, they tell her that she's uncool
'Cause she's still preoccupied with 19, 19, 1985, 1985
She's seen all the classics, she knows every line
Breakfast Club, Pretty in Pink, even Saint Elmo's Fire
She rocked out to Wham, not a big Limp Bizkit fan
Thought she'd get a hand on a member of Duran Duran
Where's the mini-skirt made of snake skin?
And who's the other guy that's singing in Van Halen?
When did reality become TV?
Whatever happened to sitcoms, game shows on the radio?
On the radio was Springsteen, Madonna, way before Nirvana
There was U2 and Blondie, and music still on MTV
Her two kids in high school, they tell her that she's uncool
'Cause she's still preoccupied with 19, 19, 1985
She hates time, make it stop
When did Mötley Crüe become classic rock? (Classic rock)
And when did Ozzy become an actor?
Please make this stop, stop, STOP!
And bring back Springsteen, Madonna, way before Nirvana
There was U2 and Blondie, and music still on MTV
Her two kids in high school, they tell her that she's uncool
'Cause she's still preoccupied with 1985
Bruce Springsteen, Madonna, way before Nirvana
There was U2 and Blondie, and music still on MTV
Her two kids in high school, they tell her that she's uncool
'Cause she's still preoccupied with 19, 19, 1985

Support beginning-of-line and end-of-line matching

Input:

java -jar target/javagrep-1.0-SNAPSHOT.jar org.dojo.grep.Main "^A" target/test-classes/rockbands.txt

Output:

AC/DC
Aerosmith
Accept
April Wine
Autograph

Input:

java -jar target/javagrep-1.0-SNAPSHOT.jar org.dojo.grep.Main "na$" target/test-classes/rockbands.txt

Output:

Nirvana

Support case-insensitive search

Input:

java -jar target/javagrep-1.0-SNAPSHOT.jar org.dojo.grep.Main A target/test-classes/rockbands.txt | wc -l

Output:

8

Input:

java -jar target/javagrep-1.0-SNAPSHOT.jar org.dojo.grep.Main -i A target/test-classes/rockbands.txt | wc -l

Output:

58