review session 1 scripts

review_session_scripts/factorial.pl

@@ -0,0 +1,15 @@
+#!/usr/bin/perl
+use strict;
+use warnings;
+my $n = shift;
+my $i = $n; # make a copy of $n and change that so
+# $n keeps the original value entered on the command line
+my $factorial = 1;
+while ($i > 1) {
+    $factorial *= $i; # same as $factorial = $factorial * $i ;
+    print "intermediate value $factorial\n";
+    $i--;
+}
+# now you can print the value of $n
+print "factorial $n = $factorial\n";
+

review_session_scripts/head.pl

@@ -0,0 +1,54 @@
+#!/usr/bin/perl
+use warnings;
+use strict;
+# pass filename and number of lines to read from the file on command line
+
+my $arg1 = shift;
+my $arg2 = shift;
+
+open(my $fh, "<", $arg1);
+
+
+
+
+
+
+
+print "\n\nWith while loop------------------\n\n";
+
+my $count = 0;
+while ( $count < $arg2  )   {
+    my $line = <$fh>; #read a line from the file
+    chomp $line;
+    print "$line\n";
+    $count++;
+}
+
+print "\n\n\n---- with while loop and last ----\n";
+close($fh);
+
+open($fh,"<",$arg1);
+
+#simon doesn't recommend this version - extra complexity
+ $count = 0;
+while ( my $line = <$fh>) {
+    chomp $line;
+    print "$line\n";
+    $count++;
+    if ($count >= $arg2) {
+	last;
+    }
+
+}
+
+close($fh);
+open($fh,"<",$arg1);
+
+print "\n\n\n--- with for loop -----\n\n";
+# start from zero for array indices, string offsets (perl internals)
+# start from one if printing lines for humans
+for (my $i =0 ; $i < $arg2  ;$i++) {
+    my $line = <$fh>;
+    chomp $line;
+    print "$line\n";
+}

review_session_scripts/text.txt

@@ -0,0 +1,15 @@
+the representation of written language
+Text (literary theory), a concept in literary theory
+Another name for a literary work
+A particular Bible passage, sometimes a single verse or verse fragment
+Textbook, a standardized instructional book
+in electronic communication and computing 
+More lines
+Will go
+something
+like this
+and we'll still
+run
+out
+probably
+Enough!