Need a regex or some other method to convert UNIX path to DOS path.
I have
C:/My Document/Photo.gif
Need
C:\My Document\Photo.gif
#!/usr/bin/perl
use strict; use warnings;
use File::Spec::Win32;
print File::Spec::Win32->canonpath('C:/My Document/Photo.gif'), "\n";
This is the regular expression
s/\//\\/g
First off, you do not normally need to do that mapping unless you are going to invoke something via cmd.exe; the Windows API is perfectly happy with slashes instead of backslashes in file names (but cmd.exe insists that slash starts an option).
Then, the direct answer to your question is perhaps:
my $file = "C:/My Documents/Photo.gif";
$file =~ s{/}{\\}g;
print "$file\n";
Just replace / with \. Though I must point out that you can use forward-slashes in Windows.
A bit superfluous, but you could use tr instead of a regex:
tr!\\!/!;
Related
I am trying to capture a sub-string from a string for that i am using regx but its is not working. The error which i am getting is Can't find Unicode property definition "o"
I am using Windows machine for running the below code.
Here is the code :
use strict;
use warnings;
my $path = 'C:\APTscripts\APStress\Logs\APStress_September-18---20.44.25\APTLogs\PostBootLogs\09-18-2014_15-18-32\UILogs_09-18-2014_15-50-43.txt';
my ($captured) = $path =~ /(.+?) \PostBootLogs/gx;
print "$captured\n";
You just need to escape the backslash in the pattern:
/(.+?) \\PostBootLogs/gx
You were inadvertently triggering the use of Unicode character properties with the use of \P.
As has already been demonstrated, you need to escape your literal backslashes in regular expressions.
my ($captured) = $path =~ /(.+?) \\PostBootLogs/x;
However, you can also accomplish this same task without a regex though if you use Path::Class or a similar file and directory managing module.
use Path::Class;
my $captured = file($path)->dir->parent->parent;
Is there a way in Perl to preserve and print all backslashes in a string variable?
For example:
$str = 'a\\b';
The output is
a\b
but I need
a\\b
The problem is can't process the string in any way to escape the backslashes because
I have to read complex regular expressions from a database and don't know in which combination and number they appear and have to print them exactly as they are on a web page.
I tried with template toolkit and html and html_entity filters. The only way it works so far is to use a single quoted here document:
print <<'XYZ';
a\\b
XYZ
But then I can't interpolate variables which makes this solution useless.
I tried to write a string to a web page, into file and on the shell, but no luck, always one backslash disappears. Maybe I am totally on the wrong track, but what is the correct way to print complex regular expressions including backslashes in all combinations and numbers without any changes?
In other words:
I have a database containing hundreds of regular expressions as string data. I want to read them with perl and print them on a web page exatly as they are in the database.
There are all the time changes to these regular expressions by many administrators so I don't know in advance how and what to escape.
A typical example would look like this:
'C:\\test\\file \S+'
but it could change the next day to
'\S+ C:\\test\\file'
Maybe a correct conclusion would be to escape every backslash exactly one time no matter in which combination and in which number it appears? This would mean it works to double them up. Then the problem isn't as big as I feared. I tested it on the bash and it works with two and even three backslashes in a row (4 backslaches print 2 ones and 6 backslashes print 3 ones).
The backslash only has significance to Perl when it occurs in Perl source code, e.g.: your assignment of a literal string to a variable:
my $str = 'a\\b';
However, if you read data from a file (or a database or socket etc) any backslashes in the data you read will be preserved without you needing to take any special steps.
my $str = 'a\\b';
print $str;
This prints a\\b.
Use
my $str = 'a\\\\b';
instead
It's a PITA, but you will just have to double up the backslashes, e.g.
a\\\\b
Otherwise, you could store the backslash in another variable, and interpolate that.
The minimum to get two slashes is (unfortunately) three slashes:
use 5.016;
my $a = 'a\\\b';
say $a;
The problem I tried to solve does not exist. I confused initializing a string directly in the code with using the html forms. Using a string inside the code preserving all backslashes is only possible either with a here document or by reading a textfile containing the string. But if I just use the html form on a web page to insert a string and use escapeHTML() from the CGI module it takes care of all and you can insert the most wired combinations of special characters. They all get displayed and preserved exactly as inserted. So I should have started directly with html and database operations instead of trying to examine things first
by using strings directly in the code. Anyway, thanks for your help.
You can use the following regular expression to form your string correctly:
my $str = 'a\\b';
$str =~ s/\\/\\\\/g;
print "$str\n";
This prints a\\b.
EDIT:
You can use non-interpolating here-document instead:
my $str = <<'EOF';
a\\b
EOF
print "$str\n";
This still prints a\\b.
Grant's answer provided the hint I needed. Some of the other answers did not match Perl's operation on my system so ...
#!/usr/bin/perl
use warnings;
use strict;
my $var = 'content';
print "\'\"\N{U+0050}\\\\\\$var\n";
print <<END;
\'\"\N{U+0050}\\\\\\$var\n
END
print '\'\"\N{U+0050}\\\\\\$var\n'.$/;
my $str = '\'\"\N{U+0050}\\\\\\$var\n';
print $str.$/;
print #ARGV;
print $/;
Called from bash ... using the bash means of escaping in quotes which changes \' to '\''.
jamie#debian:~$ ./ft.pl '\'\''\"\N{U+0050}\\\\\\$var\n'
'"P\\\content
'"P\\\content
'\"\N{U+0050}\\\$var\n
'\"\N{U+0050}\\\$var\n
\'\"\N{U+0050}\\\\\\$var\n
The final line, with six backslashes in the middle, was what I had expected. Reality differed.
So:
"in here \" is interpolated
in HEREDOC \ is interpolated
'in single quotes only \' is interpolated and only for \ and ' (are there more?)
my $str = 'same limited \ interpolation';
perl.pl 'escape using bash rules' with #ARGV is not interpolated
my $c= 'ODD_`!"£$%^&*(){}][##;:/?.>,<|\'
I want to replace all of them into as special character
how achiveve this in faster way ..
my $c= 'ODD_\`\!\"\£\$\%\^\&\*\(\)\{\}\]\[\#\,\;\:\/\?\.\>\,\<\|\\'
Use quotemeta:
#!/usr/bin/env perl
use warnings; use strict;
my $c = 'ODD_`!"£$%^&*(){}][##;:/?.>,<|\\';
print quotemeta($c), "\n";
Note that your definition of $c would not compile as you have to escape \ even in single quoted strings.
While I think that Sinan's answer is correct for what I am assuming you need (based on your list of characters to escape), for completeness I will add the module URI::Escape which escapes the metacharacters in HTML text. It does seem that it has some facility to specify the unsafe characters though, so perhaps it could help you too.
I've had a search around, and from my perspective using backticks is the only way I can solve this problem. I'm trying to call the mdls command from Perl for each file in a directory to find it's last accessed time. The issue I'm having is that in the file names I have from find I have unescaped spaces which bash obviously doesn't like. Is there an easy way to escape all of the white space in my file names before passing them to mdls. Please forgive me if this is an obvious question. I'm quite new to Perl.
my $top_dir = '/Volumes/hydrogen/FLAC';
sub wanted { # Learn about sub routines
if ($File::Find::name) {
my $curr_file_path = $File::Find::name. "\n";
`mdls $curr_file_path`;
print $_;
}
}
find(\&wanted, $top_dir);
If you are JUST wanting "last access time" in terms of of the OS last access time, mdls is the wrong tool. Use perl's stat. If you want last access time in terms of the Mac registered application (ie, a song by Quicktime or iTunes) then mdls is potentially the right tool. (You could also use osascript to query the Mac app directly...)
Backticks are for capturing the text return. Since you are using mdls, I assume capturing and parsing the text is still to come.
So there are several methods:
Use the list form of system and the quoting is not necessary (if you
don't care about the return text);
Use String::ShellQuote to escape the file name before sending to sh;
Build the string and enclose in single quotes prior to sending to sending to the shell. This is harder than it sounds because files names with single quotes defeats your quotes! For example, sam's song.mp4 is a legal file name, but if you surround with single quotes you get 'sam's song.mp4' which is not what you meant...
Use open to open a pipe to the output of the child process like this: open my $fh, '-|', "mdls", "$curr_file" or die "$!";
Example of String::ShellQuote:
use strict; use warnings;
use String::ShellQuote;
use File::Find;
my $top_dir = '/Users/andrew/music/iTunes/iTunes Music/Music';
sub wanted {
if ($File::Find::name) {
my $curr_file = "$File::Find::name";
my $rtr;
return if -d;
my $exec="mdls ".shell_quote($curr_file);
$rtr=`$exec`;
print "$rtr\n\n";
}
}
find(\&wanted, $top_dir);
Example of pipe:
use strict; use warnings;
use String::ShellQuote;
use File::Find;
my $top_dir = '/Users/andrew/music/iTunes/iTunes Music/Music';
sub wanted {
if ($File::Find::name) {
my $curr_file = "$File::Find::name";
my $rtr;
return if -d;
open my $fh, '-|', "mdls", "$curr_file" or die "$!";
{ local $/; $rtr=<$fh>; }
close $fh or die "$!";
print "$rtr\n\n";
}
}
find(\&wanted, $top_dir);
If you're sure the filenames don't contain newlines (either CR or LF), then pretty much all Unix shells accept backslash quoting, and Perl has the quotemeta function to apply it.
my $curr_file_path = quotemeta($File::Find::name);
my $time = `mdls $curr_file_path`;
Unfortunately, that doesn't work for filenames with newlines, because the shell handles a backslash followed by a newline by deleting both characters instead of just the backslash. So to be really safe, use String::ShellQuote:
use String::ShellQuote;
...
my $curr_file_path = shell_quote($File::Find::name);
my $time = `mdls $curr_file_path`;
That should work on filenames containing anything except a NUL character, which you really shouldn't be using in filenames.
Both of these solutions are for Unix-style shells only. If you're on Windows, proper shell quoting is much trickier.
If you just want to find the last access time, is there some weird Mac reason you aren't using stat? When would it be worse than kMDItemLastUsedDate?
my $last_access = ( stat($file) )[8];
It seems kMDItemLastUsedDate isn't always updated to the last access time. If you work with a file through the terminal (e.g. cat, more), kMDItemLastUsedDate doesn't change but the value that comes back from stat is right. touch appears to do the right thing in both cases.
It looks like you need stat for the real answer, but mdls if you're looking for access through applications.
You can bypass the shell by expressing the command as a list, combined with capture() from IPC::System::Simple:
use IPC::System::Simple qw(capture);
my $output = capture('mdls', $curr_file_path);
Quote the variable name inside the backticks:
`mdls "$curr_file_path"`;
`mdls '$curr_file_path'`;
I can only imagine I'm not searching correctly; this seems like an obvious question to be asked here. My apologies if this is a duplicate.
I'm writing a Perl program that will take a filename as a command-line argument. I need to convert the filename (or the filename with a relative path attached) to an absolute path (specifically to work with Win32::OLE).
I tried using Cwd's 'abs_path', and that almost does what I want, but it returns it using a Unix-style path instead of a Win32 one.
Is there a module that will convert the path, or perhaps a better module to use in the first place?
I use rel2abs from File::Spec. You have to be careful though: that might call getdcwd from Cwd, and it will assume that you want the current working directory for the current drive. If the file is on some other drive, you'll have to fix that up yourself or supply the second argument to set the base path.
use File::Spec::Functions qw(rel2abs);
print rel2abs($ARGV[0]), "\n";
my($foo) = abs_path($some_file);
$foo =~ s{/}{\\}g;
print "FOO: $foo\n";
I use Cwd's abs_path and then use a regex to convert the slashes when I really need it done. But I've found that for most uses, Unix-style slashes work just fine. It's only for the occasional "pass a filename to that annoyingly limited program" that I end up needing to convert the slashes.
use Cwd 'abs_path';
my $path = abs_path($rel_path);
# and only if necessary...
$path =~ s'[/\\]+'\\'g; # use Windows-style slashes
$path =~ s'^\\'\\\\'; # handle network path
But then.. I use a lot of network paths, with or without a mapped drive reference. Your mileage may vary.