Reading a text file in perl line by line

Reading more than one line Once we know how to read one line we can go ahead and put the readline call in the condition of a while loop. If that line has anything in it, that will evaluate to true. After we read the last line, in the next iteration the readline operator will return undef which is false. The while-loop will terminate. An edge-case There is an edge-case though when the very last line has a single 0 in it, without a trailing newline.

The above code would evaluate that line to false and the loop would not be executed. Fortunately, Perl is actually cheating here. For example when the whole job of your script is to parse that file. What if this is an optional configuration file? If you can read it you change some settings, if you cannot read you just use the defaults. In that case the second solution might be a better way to write your code.

If it is true we go ahead and read the content of the file. If it failed we give a warning using the built-in warn function but don't throw an exception.

File reading operations is very important and useful to read the content of the file. There are basically three types of methods available to read the file i. File handler using the operator is the most important and useful method available in Perl to read any file. Below is the various method which was available to read a file are as follows.

File reading operations is very important and useful in Perl to read the content of file. Below is the mode to read and opened the file to access for various operations on file. Below is the different types of ways or methods available to read the file are as follows. In Perl read file is used to read the content of a file, in Perl we have assigning file handler to perform the various file operations on the file. File handler using the operator is the most important and useful method available to read any file in Perl.

Open file name as abc. Regular Expressions. File Handling. CGI Programming. Table of Contents. Improve Article. Save Article. Like Article. Last Updated : 26 Feb, Opening a File. Opening the file. Reading First line from the file. Reading First char from the file. Printing one line at a time. Initializing filename. Prints an error and exits if file not found.