Name

Perl::Syntax -- Syntax Check Perl files and strings

Summary

This module syntax checks Perl files and strings. It is identical to running perl -c ..., but output doesn't go by default to STDOUT.

You run his like this from a command line:

    $ perl -MPerl::Syntax perl-program.pl
    $ perl -MPerl::Syntax -e 'your perl code' 

which is like:

    $ perl -c perl-program.pl 2>/dev/null
    $ perl -MPerl::Syntax -e 'your perl code' 2>/dev/null

Or from inside Perl:

     system($^X, '-M', 'Perl::Syntax', $perl_program);
     system("$^X -M Perl::Syntax $perl_program");
     # check $? 

By default, no output is produced. You will get a zero return code if everything checks out or nonzero if there was a syntax error.

To capture output to a file, you can specify a file name by adding an equal sign after "Perl::Syntax" like this:

    perl -MPerl::Syntax=/tmp/output-file.txt perl-program.pl 

or inside PerL:

     system($^X, '-M', 'Perl::Syntax=/tmp/outfile-file.txt', $perl_program);

File /tmp/output-file.txt will have either the messages Perl normally produces on STDERR:

    XXXX syntax OK

or

    syntax error at XXXX line DDDD ...
    ...

Examples

     use English;
     my @prefix = ($EXECUTABLE_NAME, '-MPerl::Syntax');

     # test this Perl code to see if it is syntactically correct;
     system(@prefix, __FILE__); 
     print "Yep, we're good" unless $? >> 8;

     # test of invalid Perl code: 
     system(@prefix, '-e', '$Incomplete + $Expression +'; 
     print "Try again" if $? >> 8;

     # Show capturing output
     system($EXECUTABLE_NAME, '-MPerl::Syntax=/tmp/Syntax.log', __FILE__);
     # results are in /tmp/Syntax.log

Bugs/Caveats

There doesn't seem to be much benefit here over using perl -c with STDERR redirected. What I really want is a kind of eval that just does the syntax checking.

Author

Rocky Bernstein

See Also

-c switch from perlrun#Command-Switches

Copyright

Copyright (C) 2012 Rocky Bernstein <rocky@cpan.org>

This program is distributed WITHOUT ANY WARRANTY, including but not limited to the implied warranties of merchantability or fitness for a particular purpose.

The program is free software. You may distribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation (either version 2 or any later version) and the Perl Artistic License as published by O'Reilly Media, Inc. Please open the files named gpl-2.0.txt and Artistic for a copy of these licenses.

cpanm Perl::Syntax

perl -MCPAN -e shell
install Perl::Syntax