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diff --git a/doc/perltest.txt b/doc/perltest.txt new file mode 100644 index 0000000..bb1a52a --- /dev/null +++ b/doc/perltest.txt @@ -0,0 +1,42 @@ +The perltest program +-------------------- + +The perltest.pl script tests Perl's regular expressions; it has the same +specification as pcretest, and so can be given identical input, except that +input patterns can be followed only by Perl's lower case modifiers and certain +other pcretest modifiers that are either handled or ignored: + + /+ recognized and handled by perltest + /++ the second + is ignored + /8 recognized and handled by perltest + /J ignored + /K ignored + /W ignored + /S ignored + /SS ignored + /Y ignored + +The pcretest \Y escape in data lines is removed before matching. The data lines +are processed as Perl double-quoted strings, so if they contain " $ or @ +characters, these have to be escaped. For this reason, all such characters in +the Perl-compatible testinput1 file are escaped so that they can be used for +perltest as well as for pcretest. The special upper case pattern modifiers such +as /A that pcretest recognizes, and its special data line escapes, are not used +in the Perl-compatible test file. The output should be identical, apart from +the initial identifying banner. + +The perltest.pl script can also test UTF-8 features. It recognizes the special +modifier /8 that pcretest uses to invoke UTF-8 functionality. The testinput4 +and testinput6 files can be fed to perltest to run compatible UTF-8 tests. +However, it is necessary to add "use utf8; require Encode" to the script to +make this work correctly. I have not managed to find a way to handle this +automatically. + +The other testinput files are not suitable for feeding to perltest.pl, since +they make use of the special upper case modifiers and escapes that pcretest +uses to test certain features of PCRE. Some of these files also contain +malformed regular expressions, in order to check that PCRE diagnoses them +correctly. + +Philip Hazel +January 2012 |