Perl read line by line

Question

I have a simple Perl script to read a file line by line  Code is below  I want to display two lines and break the loop  But it doesn t work  Where is the bug    file  SnPmaster txt   open INFO   file  or die  Could not open  file       count   0   foreach  line   lt INFO gt             print  line          if     counter    2         last          close INFO

User · Answer

With these types of complex programs  it s better to let Perl generate the Perl code for you     perl -MO Deparse -pe exit if    gt 2    Which will gladly tell you the answer   LINE  while  defined       lt ARGV gt          exit if     gt  2    continue       die  -p destination     n  unless print         Alternatively  you can simply run it as such from the command line     perl -pe exit if   gt 2  file txt

User · Answer

you need to use    counter  not    counter  hence the reason it isn t working

User · Answer

usr bin perl use utf8                         use 5 10 1                       use strict                       use autodie                      use warnings FATAL   gt  q   all   binmode STDOUT       gt  q   utf8                    END   close   STDOUT                                         our     FOLIO         q   SnPmaster txt                open    FOLIO                                    END   close   FOLIO                                          binmode FOLIO        gt  q         crlf                                 encoding CP-1252        while   lt FOLIO gt      print                                      continue          015     LINE         exit                                                                                                                                                                                                                                                     END   unlink   FOLIO                   unlink   HOME      clri   HOME                    reboot

User · Answer

If you had use strict turned on  you would have found out that    foo doesn t make any sense    Here s how to do it   use strict  use warnings   my  file    SnPmaster txt   open my  info   file or die  Could not open  file        while  my  line    lt  info gt             print  line          last if       2     close  info    This takes advantage of the special variable    which keeps track of the line number in the current file   See perlvar   If you want to use a counter instead  use  my  count   0  while  my  line    lt  info gt             print  line          last if    count    2

User · Answer

In bash foo is the name of the variable  and   is an operator which means  get the value of    In perl  foo is the name of the variable

[perl] Perl read line by line

Examples related to perl