Yesterday we learnt about installing perl in windows (Didn't read yesterday's post? check here Perl programming #1 )and how to “print” using perl!
Today, let’s start with the basics, how to get input using perl?
To get a text file from user using perl:
Just it is very simple, type as follows,
This will get the file name. This also works in perl,
No need to give STDIN! Just the open and closed angular brackets are itself considered as standard input.
Then, always give chomp after the standard input, this chomp is nothing but “chop” which chops the “enter” à new line character i.e., whenever you give an input, you press “enter” which will be considered as a new line character. In order to remove that new line character, chomp must be given.
How to use chomp? Use as follows,
Simple, this chops the new line character from your input.
Let us look at sample program for getting a text file and a word or pattern.
Program for getting a DNAFILE and printing the file content: (sample.pl)
print "enter a dna sequence file\n";
|O/P of the program sample.pl|
“close” is used for closing the file,
Program for getting a pattern or word from the user and printing it (sample1.pl)
|O/P of the program sample1.pl|
Try printing the output, after using “join” and the line “$dna=~s/\s//g” for knowing their difference. Here “g” stands for global i.e., removes the space globally.
Any doubts? Kindly comment. I’ll try to clear your doubts.
:) Happy perl-ing :)