LING/C SC/PSYC 438/538. Lecture 6 Sandiway Fong

Transcription

1 LING/C SC/PSYC 438/538 Lecture 6 Sandiway Fong

2 Today s Topic Homework 2 out today due next Thursday by midnight submit one file only (preferably PDF) Subject line: Your Name 538/438 Homework 2 Perl Recap file I/O, references, arrays Perl iteraton Perl Modules Homework 2

3 Perl Recap File I/O open($txtfile, $ARGV[0]) or die "$ARGV[0] not found!\n"; while ($line = <$txtfile>) { print "$line"; } References: $aref = [ ITEMS ] $aref is a reference to an the array ${$aref}[0] first element of the array $href = { ITEMS } $href is a reference to a hash %{$href} the hash ${$href}{key} the value associated with key in the hash

4 Perl Arrays FuncTons on arrays: From the front: shib array unshib array, list From the back: pop array push array, list generalized functon

5 Perl Strings and Arrays Strings and arrays chomp vs. chop split a string into words

6 IteraTon We ve already seen for/foreach: foreach $var {.. do something with $var.. } for- = qw(this is a short sentence); for (my $i=0; $i<$#words; $i++){ } do something with

7 SorTng revisited From two lectures ago Sort (cmp - strings, <=> - numeric): Perl version 5.16 onwards has fc (fold case) functon Unicode compatble Unicode::CaseFold module has a functon fc Standard functon is called lc (lowercase) Works for ASCII Also functons uc/ucfirst

8 Experiment Unicode encoding (ul- 8)

9 Module not downloaded bash- 3.2$ perl test.perl Can't locate Unicode/CaseFold.pm contains: /Library/Perl/5.12/ darwin- thread- mult- 2level /Library/Perl/5.12 /Network/Library/Perl/5.12/darwin- thread- mult- 2level /Network/Library/Perl/5.12 /Library/Perl/Updates/ / System/Library/Perl/5.12/darwin- thread- mult- 2level /System/Library/Perl/5.12 / System/Library/Perl/Extras/5.12/darwin- thread- mult- 2level /System/Library/Perl/ Extras/5.12.) at test.perl line 1. BEGIN failed- - compilaton aborted at test.perl line 1.

10 cpanm Example (command line): cpanm Unicode::CaseFold installing cpanminus (cpanm) cpanminus is a script to get, unpack, build and install modules from CPAN and does nothing else. assume command line program curl (curl) to get cpanm from the internet curl is a command line tool for genng or sending files using URL syntax

11 cpanm

12 cpamn bash- 3.2$ which cpanm bash- 3.curl - L h:p://cpanmin.us perl sudo App::cpanminus % Total % Received % Xferd Average Speed Time Time Time Current Dload Upload Total Spent Leb Speed :- - :- - 0:00: :- - : k k :00:11 0:00: :- - : > Working on App::cpanminus Fetching hrp:// cpanminus tar.gz... OK Configuring App- cpanminus OK Building and testng App- cpanminus Password: OK Successfully installed App- cpanminus distributon installed bash- 3.2$ which cpanm /usr/local/bin/cpanm bash- 3.2$

13 Cpanm Unicode::CaseFold bash- 3.2$ cpanm Unicode::CaseFold!! Can't write to /Library/Perl/5.12 and /usr/local/bin: Installing modules to /Users/sandiway/perl5! To turn off this warning, you have to do one of the following:! - run me as a root or with - - sudo opton (to install to /Library/Perl/5.12 and /usr/local/bin)! - Configure local::lib your existng local::lib in this shell to set PERL_MM_OPT etc.! - Install local::lib by running the following commands!! cpanm - - local- lib=~/perl5 local::lib && eval $(perl - I ~/perl5/lib/perl5/ - Mlocal::lib)! - - > Working on Unicode::CaseFold Fetching hrp:// CaseFold tar.gz... OK Configuring Unicode- CaseFold OK Building and testng Unicode- CaseFold OK Successfully installed Unicode- CaseFold distributon installed No root access

14 Cpanm Unicode::CaseFold bash- 3.2$ sudo cpanm Unicode::CaseFold - - > Working on Unicode::CaseFold Fetching hrp:// CaseFold tar.gz... OK Configuring Unicode- CaseFold OK Building and testng Unicode- CaseFold OK Successfully installed Unicode- CaseFold distributon installed With root access

15 Appendix: command line tools For the mac (10.8), command line tools are not installed even if you install XCode

16 Appendix: command line tools Xcode: Preferences

17 Appendix: command line tools make

18 Homework 2 QuesTon 1 (10pts) Create a file data.txt (example): I saw the cat on on the mat. The the the cat sat on the mat. Write a Perl program that detects repeated words (many spell check/grammar programs can do this) Your program should read in data.txt and print a message statng the line number, the repeated word and its positon if one exists. Example output: perl repeated.perl data.txt Line 1: word 5, on repeated 2 times Line 2: word 1, the repeated 3 times Note: case Submit your program and examples of its output

19 Homework 2 QuesTon 2: (10 pts) describe how a repeated word program could stop flagging legitmate examples of repeated words in a sentence Examples: I wish that that ques8on had an answer Because he had had too many beers already, he skipped the Friday office happy hour

20 Microsob Word: Homework 2