I have a perl code where I access multiple txt files and produce output for them.
While I run the code, the output lines on the console are overwritten.
2015-04-21:12-04-54|getFilesInInputDir| ********** name : PEPORT **********
PEPORT4-21:12-04-54|readNFormOutputFile| name :
PEPORT" is : -04-54|readNFormOutputFile| Frequency for name "
Please note, that the second and third line it should have been like
2015-04-21:12-04-54|readNFormOutputFile| name : PEPORT
2015-04-21:12-04-54|readNFormOutputFile| Frequency for name "PEPORT"
Also, after this the code stops processing my files. The code seems fine. May I know what may be the possible cause for this.
Thanks.
Seems like CR/LF versus LF issue. Convert your input from MSWin to Linux by running dos2unix or fromdos, or remove the "\r" characters from within the Perl code.
As choroba says, I guess you are reading a file on Linux that has been generated on Windows. The easiest fix is to replace chomp with s/\s+\z//or s/\p{cntrl}+\z//
Or, if trailing spaces are significant, you can use s/[\r\n]+\z// or, if you are running version 10 or later of Perl 5, s/\R\z//
Related
I wrote a Perl script to convert from TEX format to JSON format.
Calling in the batch file:
perl -w C:\test\support.pl TestingSample.tex
This is working fine now.
Perl script having two types of input from another program (might be any platform/technology) one is file (*TEX) or else content (*TEX file) either this or that option.
How can I receive the full content as the input to the Perl script?
Now my Perl script is:
my $texfile = $ARGV[0]; my $texcnt = "";
readFileinString($texfile, \$texcnt);
I am trying to update:
perl -w C:/test/support.pl --input $texcnt" #Content is Input
I am receiving error message:
The command line is too long.
Could someone please advice?
First of all regarding the error you're getting:
Perl (or your shell) is complaining that your input argument is too long.
Parsing entire files as arguments to scripts is generally a bad idea anyway, for example quotation mark escaping etc. might not be handled and thus leave a wide open vulnarbility to your entire system!
So the solution to this is to modify your script so that it can take the file as an argument (if that isn't already the case) and if you really need to have an entire file's content parsed as an argument I'd really advise you to create a temporary file in /tmp/ (if on Linux) or in your %TEMP% directory on Windows and parse the file the content into the file and after that give your support.pl script the new temp file as an argument.
I am currently working on a project but I have one big problem. I have some picture with a whitespace in the name and I want to do a montage. The problem is that I can't rename my picture and my code is like that :
$pic1 = qq(picture one.png);
$pic2 = qq(picture two.png);
my $cmd = "C:\...\montage.exe $pic1 $pic2 output.png";
system($cmd);
but because of the whitespace montage.exe doesn't work. How can I execute my code without renaming all my pictures?
Thanks a lot for your answer!
You can properly quote the filenames within the string you pass to system, as #Borodin shows in his answer. Something like: system("montage.exe '$pic1' '$pic2'")
However, A more reliable and safer solution is to pass the arguments to montage.exe as extra parameters in the system call:
system('montage.exe', $pic2, $pic2, 'output.png')
Now you don't have to worry about nesting the correct quotes, or worry about files with unexpected characters. Not only is this simpler code, but it avoids malicious injection issues, should those file names ever come from a tainted source. Someone could enter | rm *, but your system call will not remove all your files for you.
Further, in real life, you probably are not going to have a separate scalar variable for each file name. You'll have them in an array. This makes your system call even easier:
system('montage.exe', #filenames, 'output.png')
Not only is that super easy, but it avoids the pitfall of having a command line too long. If your filenames have nice long paths (maybe 50-100 characters), a Windows command line will exceed the max command length after around 100 files. Passing the arguments through system() instead of in one big string avoids that limitation.
Alternatively, you can pass the arguments to montage.exe as a list (instead of concatenating them all into a string):
use strict;
use warnings;
my $pic1 = qq(picture one.png);
my $pic2 = qq(picture two.png);
my #cmd = ("C:\...\montage.exe", $pic1, $pic2, "output.png");
system(#cmd);
You need to put quotes around the file names that have spaces. You also need to escape the backslashes
my $cmd = qq{C:\\...\\montage.exe "$pic1" "$pic2" output.png};
In unix systems, the best approach is the multi-argument form of system because 1) it avoids invoking a shell, and 2) that's the format accepted by the OS call. Neither of those are true in Windows. The OS call to spawn a program expects a command line, and system's attempt to form this command line is sometimes incorrect. The safest approach is to use Win32::ShellQuote.
use Win32::ShellQuote qw( quote_system );
system quote_system("C:\\...\\montage.exe", $pic1, $pic2, "output.png");
I have a CGI script that's used by our employees to fetch logs from servers that they don't have direct access to. For reasons I won't go into, after a recent update to our app some of these logs now have characters like linefeeds, tabs, backslashes, etc. translated into their text equivalents. As such, I've modified the CGI script to invoke the following to convert these back to their original values:
perl -i -pe 's/\\r/\r/g && s/\\n/\n/g && s/\\t/\t/g && s/\\\//\//g' $filename
I was just informed that some people are now getting out of memory errors when they try to fetch logs that are fairly large (a few hundred MB).
My question: How does perl manage memory when an inline command like this is invoked? Is it reading the whole file in, processing it, then writing it out, or is it creating a temporary file, processing the lines from the input file one at a time then replacing the file once complete?
This is using perl 5.10.1 on a 64-bit Amazon linux instance.
The -p switch creates a while(<>){...; print} loop to iterate on each “line” in your input file.
If all of your newlines have been converted into "\\n", then your file would just be a single very long line. Therefore, your command would be loading the entire file into memory to perform your fix.
To avoid that, you'll have to intentionally buffer the file using either sysread or $/.
It would probably be easiest to create an actual script instead of a one-liner to do the work. However, if you know that all of your newlines are converted, then one simple fix would be to use $/ = "\\n"
As a secondary note, your regex is flawed. You're currently listing out your translations s/// using a shortcut operator. If any one of the earlier regexes doesn't match for a particular line, then no other translations would be attempted. You should instead use simple semicolons to separate your regexes:
's/\\r/\r/g; s/\\n/\n/g; s/\\t/\t/g; s|\\/|/|g'
There is a line in a library that I can't take out:
put oResults format "x(80)" skip.
I have a program that is calling the library that doesn't have a default output so this line errors out.
I know I can just send output in my program somewhere but I want to fix it so you don't have to have a output. Seek function maybe?
EDIT: 10.2b
I only get an error in unix.
In a unix environment this line:
put oResults format "x(80)" skip.
errors out.
but if you put a:
if seek(output) <> ? then
put oResults format "x(80)" skip.
it doesn't error.
in a unix environment line:
put oResults format "x(80)" skip.
errors out.
but if you put a:
if seek(output) <> ? then
put oResults format "x(80)" skip.
it doesn't error.
You are running in batch mode. You should always be redirecting your output at the OS level when you run in batch mode. Something like this:
bpro -p test.p > errors.out 2>&1
Not redirecting output will pretty much always lead to the error that you are seeing.
If you are embedding the bpro, mbpro or _progres -b or whatever command in a script that needs to show that output or otherwise work with it you would typically use "cat" or "tail -f" on the output file.
While using tar->write() I am getting errors while using complex file names.
The code is:
my $filename= $archive_type."_".$from_date_time."_".$to_date_time."tar";
$tar->write($filename);
The error i get is:
Could not create filehandle for 'postProcessProbe_2010/6/23/3_2010/6/23/7.tar':
No such file or directory at test.pl line 24
If I change the $filename to a simple string like out.tar everything works.
Well, / is the directory separator on *nix systems (and, internally Windows treats / and \ interchangeably) and I believe tar files, regardless of platform use it internally as the directory separator.
I do not think you can create file names containing / on either *nix or Windows based systems. Even if you could, that would probably create a whole bunch of headaches down the road.
It would be better in my humble opinion to switch to a saner date format such as YYYYMMDD.
Also, you are using string concatenation when sprintf would have been much clearer:
my $filename= sprintf '%s_%s_%s.tar', $archive_type, $from_date_time, , $to_date_time;