Perl Guru Forums: Perl Programming Help: Beginner: Noob ? about Regular Expressions

CGI/Perl Guide | Learning Center | Forums | Advertise | Login

Site Search: in


	MAIN INDEX	SEARCH POSTS	WHO'S ONLINE	LOG IN

Home: Perl Programming Help: Beginner:
Noob ? about Regular Expressions

200mg
New User

May 26, 2009, 7:52 AM

Post #1 of 3 (1611 views)

Noob ? about Regular Expressions	Can't Post

I am trying to run winzip via command line and then parse the output for the word "Error" and I am wondering why what I have will not work, I have purposefully placed a corrupted zip file into a folder containing several zip files and the wzunzip output says the word "Error" in the 2nd line, but when I try the following it just shows the output of running wzunzip and not the following part that should confirm the word "Error" is in the output.

Code

use warnings; 
use strict; 
 
$_ = print `wzunzip -o c:\\begperl\\zips\\*.zip`; 
if ($_ =~ /Error/) { 
    print "found the word 'error'\n"; 
                 }

Here is a sample of the wzunzip output, after playing with it for a while i think this is happening because it doesn't read past the empty lines, i think it's only reading "Zip file: c:\begperl\zips\1.zip" and then stops.

Code

Zip file: c:\begperl\zips\1.zip 
 
Error [c:\begperl\zips\1.zip]:  unrecoverable zip file read error 
 
Zip file: c:\begperl\zips\792112CL.ZIP 
 
unzipping 792112CL.LBL 
 
Zip file: c:\begperl\zips\792113CL.ZIP 
 
unzipping 792113CL.LBL 
 
Zip file: c:\begperl\zips\793489CF.ZIP 
 
unzipping 793489CF.LBL 
 
Zip file: c:\begperl\zips\793609CF054.ZIP

(This post was edited by 200mg on May 26, 2009, 8:34 AM)

1arryb
User

May 26, 2009, 1:42 PM

Post #2 of 3 (1601 views)

Re: [200mg] Noob ? about Regular Expressions [In reply to]	Can't Post

Hi 200mg,

You don't need the print to get the output of a command, so, if the standard output of winzip can contain /Error/, then:

Code

$_ = `winzip -o c:\\begperl\\zips\\*.zip`;

should suffice.

However, you shouldn't use the global '$_' variable for your own data. Better would be:

Code

my $ret = `winzip -o c:\\begperl\\zips\\*.zip`;

However, Perl backticks (``) only give you the standard output from the command. Since you are looking for an error string, you may only find it on the standard error file descriptor, not the standard output. If you were using L/Unix or running your script from a cygwin bash window, you could redirect stderr to stdout. Then /Error/ would be guaranteed to be in the backtick output:

Code

my $ret = `winzip -o c:\\begperl\\zips\\*.zip 2>&1`;

However, since you are really only interested in whether winzip succeeded, you might try:

Code

my $ret = `winzip -o c:\\begperl\\zips\\*.zip 2>&1`; 
if ( $? != 0 ) { 
    print "winzip failed. Error was:\n"; 
    print $ret; 
}

Whether this will work or not depends on whether winzip exits with an error status on failure (hint: RTM).

Cheers,

Larry

200mg
New User

May 26, 2009, 3:26 PM

Post #3 of 3 (1597 views)

Re: [1arryb] Noob ? about Regular Expressions [In reply to]	Can't Post

TY very much for your reply 1arryb.

Winzip does show the error in the regular backtick output & Winzip does not exit on error, instead it logs the error and then keeps on unzipping whatever files are left. What I am trying to do is make a script that is aware of corrupted zip files, deletes them and emails the originator that the file was corrupted and to please re-up the file. I waited too long to learn a prog. lang and decided I would start with perl. So far so good. I log the output to a txt file that I parse for the word "Error" and then print the line containing the word error to another file and make that text a variable. I will be able to pass that variable to a windows command to delete the file. Now I have to work on getting that captured filename into the subject line of an email. Here is what I have so far. I am a super noob at this so it probably looks bad to a guru but it works =)

Code

use warnings; 
use strict; 
 
open (MYFILE, '>c:\\begperl\\logs\\data.txt'); 
print `wzunzip -o c:\\begperl\\zips\\*.zip > c:\\begperl\\logs\\1.log`;         #Executes winzip and logs output to 1.log 
my $var1 = "Error";                                                             #Sets Search Criteria for "Error" 
while (<>) {print MYFILE if /$var1/;}                                           #(<>) Sets script to look for input file and Prints the line if Search Criteria has been met 
close (MYFILE); 
open FILE, "c:\\begperl\\logs\\data.txt" or die $!;                             #Opens data.txt file 
my $var2 = <FILE>;                                                              #Sets $var2 to text in data.txt 
if ($var2 =~ m/zips\\(.*?)]:/i){                                                #Searches for anything between /zips and ]: and sets that as the variable $1 
    print "$1" 
}

Search for (options)

Web Applications & Managed Hosting Powered by Gossamer Threads
Visit our Mailing List Archives