Is there a module or constant somewhere in Perl that gives the equivalent of Java's File.pathSeparatorChar? I've been looking everywhere but the name easily brings up things like / and \, used to separate elements in a single path. I want the thing you use to separate values in an environment variable containing paths (: in Unix, ; in Windows, and I have no idea if there are others on other platforms).
I believe you are looking for $Config{path_sep}:
use Config;
print "path separator for $^O is '$Config{path_sep}'\n";
path separator for cygwin is ':'
(I found this be grepping for split.*PATH in the perl source code)
If you want to actually do anything with the system PATH variable, then you probably want the Env::Path module, but that indeed gets the value for the separator from $Config::Config{path_sep}.
Note that it is cleaner to use the Config module as
use Config ();
and then access the hash using the fully-qualified %Config::Config, as otherwise the module silently imports %Config into your current namespace.
Related
I have a small perl script which collects file paths from an excel file and passes them through the command line to perltex which then compiles a pdf based on the files and paths chosen.
My problem is that the moment I introduce more complex file paths (which is necessary based on the network setup of the final user pool) perltex fails to find the file paths, cutting them at the space.
A MWE is a follows
#!/usr/bin/perl
use strict;
use warnings;
use 5.14.2;
use Text::Template;
use Spreadsheet::Read;
use Spreadsheet::ParseXLSX;
use utf8;
use charnames qw( :full :short );
use autodie;
my $row = 5;
my $col = 15;
my $File = "C:/Users/me/Desktop/Reporting-Static/Input-test1.xlsm";
my $parser = Spreadsheet::ParseXLSX->new();
my $workbook = $parser->parse($File);
my $worksheet = $workbook->worksheet("Input");
my $cell = $worksheet->get_cell($row, $col);
my $Filename = $cell->Value();
my $texfile = "C:/Users/me/Desktop/Reporting-Static/file.tex";
# can't find this file if there are spaces in the address
system("perltex", "--latex=pdflatex", "--nosafe", "--jobname=$Filename", "$texfile");
if ( $? == -1 )
{
print "command failed: $!\n";
}
else
{
printf "command exited with value %d", $? >> 8;
}
exit;
However, the moment I change the folder name to one with spaces eg. "Reporting Static" it fails to find the tex file.
I have read several other posts regarding this on stack exchange and other websites but for whatever reason the proposed solutions do not appear to work for me. I have tried
my $texfile = "C:/Users/me/Desktop/Reporting Static/file.tex";
my $texfile = C:/Users/me/Desktop/"Reporting Static"/file.tex;
my $texfile = "\"C:/Users/me/Desktop/"Reporting Static"/file.tex\"";
my $texfile = "\"C:/Users/me/Desktop/Reporting Static/file.tex\"";
my $texfile = "C:/Users/me/Desktop/Reporting^ Static/file.tex";
my $texfile = "C:/Users/me/Desktop/Reporting\^ Static/file.tex";
As well as a few other combinations or varioations of the above, all without success. I have also tried replacing the double quote with a single quote so that perl doesn't interpolate the contents.
I have also tried manually typing all of the above into the command prompt to check whether there was a small issue with the way perl passed the commands to the command line but still no luck.
I am aware that I can use the 'dir /X ~1 c:\' command to find system name allocations that avoid spaces but the idea is that the filename and location will be dynamic and change as a funtion of department and site, so I would prefer to avoid trying to write a script which will go and find this pathname and use it to replace all locations using spaces or other special characters.
The final idea that I had is that this problem could be connected ot the way that perltex passes it's arguments yet I am unable to find any documentation (that I can follow...) on the specifics of how this particular aspect of the file functions.
So my questions are, is there something I am missing not metioned in the other answers that I have read regarding how to correctly pass these paths to perltex, is there perhaps some sort of incompatiblity in how I'm trying to go about this, is this more probabl linked to perltex as opposed to perl or cmd or is there something completely different that I am unaware of that is stopping this from working???
EDIT:
from cmd prompt perltex returns a "unable to find path X, please enter another file location". Until now I hadn't really tested retyping the path by by entering 'C:/Users/me/Desktop/"Reporting Static"/file.tex' (no quotes at the beginning) it is subsequently accepted and runs. but initially passing it this path does not work, suggesting that some internal perltex code accepts the inital path differently to being repassed the same path after an error.... not quite sure what to make of this.
EDIT:
The contents of #latexcmdline that I extracted
$VAR1 = [
'pdflatex',
'--jobname=--',
'\\makeatletter\\def\\plmac#tag{AYNNNUVKQVJGZKKPGPTH}\\def\\plmac#tofile{Perl.topl}\\def\\plmac#fromfile{Perl.frpl}\\def\\plmac#toflag{Perl.tfpl}\\def\\plmac#fromflag{Perl.ffpl}\\def\\plmac#doneflag{Perl.dfpl}\\def\\plmac#pipe{Perl.pipe}\\makeatother\\input C:/Users/me/Desktop/PERLTEST/Perl',
'Modules/RevuedeProjetDB.tex'
];
This was done by inserting
use File::Slurp;
use Data::Dumper;
write_file 'C:\Users\me\Desktop\PERLTEST\mydump.log', Dumper( \#latexcmdline );
before the exec command.
Update
I initially recommended that you should use String::ShellQuote but that module is for Linux only so I deleted my answer when I realised that your question was about the Windows system
It seems that there's also a Win32::ShellQuote which does the same thing for Windows, so I am renewing my suggestion
As I said before, the issue is that perltex itself doesn't properly handle paths containing whitespace, even if they are correctly passed as a single element of #ARGV. I believe the solution is to pass the path including enclosing quotes, although I have never been able to test this properly as I have no LaTex installation
Unfortunately, even if I pass qq{"$texfile"}, the quotes are still stripped before they reach the target program, so they must be protected in some way
You need the quote_system function from that module, which will prepare a list of strings so that they retain any quotation marks
Using a parameter of quote_system(qq{"$texfile"}) produces the correct result in my tests. It is the equivalent of passing qq{"\\"$texfile\\""} but less ugly
So your system call should be like this (with no modification to perltex.pl)
I have applied the same principle to $Filename as it may well be that this also contains whitespace
use Win32::ShellQuote 'quote_system';
system(quote_system(
'perltex',
'--latex=pdflatex',
'--nosafe',
qq{--jobname="$Filename"},
qq{"$texfile"},
));
Okay, well I have a solution of sorts
The issue, as I suspected, is that, although the path is passed as a single string to perltex.pl, the latter doesn't handle paths with spaces properly after it has received them
The temporary fix is to hack perltex.pl
Line 82 of my version of perltex.pl (there is no version number in the source) reads
$latexcmdline[$firstcmd] = "\\input $option";
If you change that to
$latexcmdline[$firstcmd] = qq{\\input "$option"};
then all should be well. However this is a solid fix only when it is distributed by the author of perltex. Meanwhile I am looking for a nicer solution from the calling side
There are two steps to solving this problem.
Work out how to get the correct arguments into an external
program.
Work out how to do that from a Perl program.
For step 1, I find a program like this to be useful.
#!/usr/bin/perl
use strict;
use warnings;
print "Received ", scalar #ARGV, " arguments:\n";
for (1 .. #ARGV) {
print "$_: $ARGV[$_ - 1]\n";
}
It just explains what arguments it receives on the command line. You can use this in place of "perltex" for testing purposes.
You'll see that if you give it an argument that contains spaces, then that is interpreted as the called program as multiple arguments. The way to get round that is to quote the argument that contains a space. And I seem to remember that Windows insists on double-quotes (for reasons that I can never remember).
So I think that you want this:
system('perltex', '--latex=pdflatex', '--nosafe', "--jobname=\"$Filename\"", "\"$texfile\"");
I've double-quoted both of the filenames. Of course, those escaped double-quote characters look really ugly, and Perl gives us qq(...) to make that look nicer.
system('perltex', '--latex=pdflatex', '--nosafe', qq(--jobname="$Filename"), qq("$texfile"));
If that's not quite right, then the program I showed earlier will make it easier to find the solution.
Update: Borodin's comment below about this making no difference to $texfile is accurate. The fact that we're passing a list to system() means that the shell isn't involved at all.
Is there a way to get an absolute path to the Perl executable for the current process?
$^X will give me the Perl executable name, but the doc states that it will sometimes be a relative path, and this seems to be true on OS X for example.
ExtUtils::MakeMaker seems to have some magic to find the absolute path, since the Makefile it generates on my OS X contains
PERL = /usr/local/bin/perl
FULLPERL = /usr/local/bin/perl
but I have no idea how it does this or whether the magic is readily accessible to others.
EDIT: Thanks Borodin for the $Config{perlpath} tip. Grepping for this in ExtUtils, I found this tidbit in ExtUtils::MM_Unix::_fixin_replace_shebang, which I guess is what MakeMaker uses to replace #!perl with the correct shebang line.
if ( $Config{startperl} =~ m,^\#!.*/perl, ) {
$interpreter = $Config{startperl};
$interpreter =~ s,^\#!,,;
}
else {
$interpreter = $Config{perlpath};
}
I think what you're looking for is $Config{perlpath}.
If you want your code to be very portable you may have to append a file type to that value; this is described in the perlport documentation. Otherwise all you need is this:
use Config;
my $perl = $Config{perlpath};
You can get it via the core Config module.
use Config;
say $Config{perl5}; # current perl binary
I think that should always contain an absolute path, but I can't guarantee it.
Perl includes the core module File::Spec which can translate relative paths to absolute paths.
my $full_path_to_perl = File::Spec->rel2abs($^X);
For perl6 (raku): $*EXECUTABLE-NAME contains full path of the currently running Raku interpreter (like sys.executable for Python)
To get the full command line:
say ($*EXECUTABLE-NAME, $*PROGRAM-NAME, |#*ARGS).join(' ');
More in Variable Documentation
I have a main program mytool.pl to be run from the command line. There are several auxillary scripts special1.pl, special2.pl, etc. which each contain a couple subroutines and a hash, all identically named across scripts. Let's suppose these are named MySpecialFunction(), AnotherSpecialFunction() and %SpecialData.
I'd like for mytool to include/use/import the contents of one of the special*.pl files, only one, according to a command line option. For example, the user will do:
bash> perl mytool.pl --specialcase=5
and mytools will use MySpecialFunction() from special5.pl, and ignore all other special*.pl files.
Is this possible and how to do it?
It's important to note that the selection of which special file to use is made at runtime, so adding a "use" at the top of mytool.pl probably isn't the right thing to do.
Note I am a long-time C programmer, not a perl expert; I may be asking something obvious.
This is for a one-off project that will turn to dust in only a month. Neither mytool.pl nor special?.pl (nor perl itself) will be of interest beyond the end of this short project. Therefore, we don't care for solutions that are elaborate or require learning some deep magic. Quick and dirty preferred. I'm guessing that Perl's module mechanism is overkill for this, but have no idea what the alternatives are.
You can use a hash or array to map values of specialcase to .pl files and require or do them as needed.
#!/usr/bin/env perl
use strict; use warnings;
my #handlers = qw(one.pl two.pl);
my ($case) = #ARGV;
$case = 0 unless defined $case;
# check that $case is within range
do $handlers[$case];
print special_function(), "\n";
When you use a module, Perl just require's the module in a BEGIN block (and imports the modules exported items). Since you want to change what script you load at runtime, call require yourself.
if ($special_case_1) {
require 'special1.pl';
# and go about your business
}
Here's a good reference on when to use use vs. require.
I created a perl script that uses abs_path but it doesn't correctly handle the home directory (represented by '~')
EG if I try to call abs_path("~/mystuff");
it returns undef
Can I make abs_path correctly handle the home directory? And if not, is there an alternative I can use?
#!/usr/bin/perl
use File::HomeDir;
print File::HomeDir->my_home;
The reason that abs_path doesn't handle it correctly is that "~" is a shell construct. Perl doesn't know anything about what "~" means - it literally treats it as "a directory named 'tilde'(~) under current working directory".
Any program to which "~" is supplied as a parameter would actually get a real directory path from shell instead.
To be able to use home directories from Perl, on Unix you can use $ENV{HOME} instead of "~" for your own home directory; or for other users use (getpwnam($user))[7]; there's no clean cross-platform way to do either.
A second approach is to use shell for dirty work in a system call:
my $expanded_home_dir = `cd ~/mydir/; pwd`;
UPDATE:
First, a very good recipe for outright replacement of tilde-home-strings is in "Perl Cookbook" (2d ed), ch. 7.3 "Expanding tildes in filenames".
Second, as daxim mentioned in comments, since Perl 5.6, CORE::glob() is actually automatically replaced with File::Glob::bsd_glob() which supports POSIX's GLOB_TILDE flag and therefore can expand tildes for you.
Interestingly enough, both bsd_glob (in C code, as per Perlmonks), and File::HomeDir mentioned wisely by Andrew Clark, use precisely the same logic underneath as the Cookbook's recipe 7.3 ($ENV{HOME}||$ENV{LOGDIR}||(getpwnam($<))[7]) for Unix environments.
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.