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Printing a "File Not Found" message in Perl.

P: 32
Hi - I know almost nothing about Perl but do program in other languages. I am looking at Perl that I have to modify slightly by printing a "file not found" message if a file is missing from the directory or the directory just above it (hence the 'find ..' ). Please help!

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  1. sub findText
  2. {
  3.   my @aray = 'find .. -name veryImprotant.txt -print';
  4.   my $var = shift @aray;
  5.   # I want to check if file is not found here maybe?
  6.   return $var;
  7. }
  8.  
Jul 10 '09 #1
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2 Replies


nithinpes
Expert 100+
P: 410
While running system commands, pass the command within reverse quotes( ` ). You have used single quotes, hence the command will not be run (it is passed as a string).

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  1. sub findText 
  2.   my @aray = `find .. -name veryImprotant.txt -print`; 
  3.   my $var = shift @aray; 
  4.   print "File not found \n" unless($var);
  5.   return $var; 
  6.  
Jul 28 '09 #2

numberwhun
Expert Mod 2.5K+
P: 3,503
@dissectcode2
Personally, I would take a different route. I would actually use the open() function to open the file and die if it didn't work. If it opened, make a log entry into a log and then close the file.

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  1. sub findText {
  2.     open(FILE, "../veryImportant.txt") or die "Cannot open file:  $!";
  3.  
  4.     print LOG "File: veryImportant.txt exists.  Continuing.";
  5.  
  6.     close(<FILE>);
  7. }
  8.  
Yes, the log file represented by the LOG file handle will have had to be previously opened, but that is no biggie. My point was to show you another way of doing it that didn't involve executing a system command. This, btw, would possibly work on Unix, Linux and maybe even Windows due to the lack of system level command execution.

Regards,

Jeff
Jul 28 '09 #3

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