Reading a File Line by Line

Reading a File Line by Line

• An often used technique in CGI scripts for the manipulation of files is the reading of each line of a file. Perhaps we want to check each line for a keyword, or find every occurrence of some marker tag on a line and replace it with some other string. This process is done using a while loop as discussed previously. Consider this routine that will print out every line in a address file:

  open (ADDRESSES, "address.dat") || 
       &CgiDie ("Cannot open address.dat");
       while (<ADDRESSES>)
         {
         print "$_";
         }
       close (ADDRESSES);
  

• Thus, the script would print out every line in the file address.dat because "$_" is Perl's special name for "the current line" in this case.

Additional Resources:

• Perl
• Perl Resources
• Instant Web Scripts With CGI

Perl File Management
Table of Contents
Writing and Appending to Files