SYNOPSIS

"tv_grep [--help] [--output FILE] [--ignore-case|-i] (EXPR | REGEXP) [FILE...]"

DESCRIPTION

Reads XMLTV listings data and writes out data containing some of the programmes and channels from the original. Which programmes and channels are left in the output is controlled by the regexp or Boolean expression given.

Simple usage is tv_grep REGEXP [FILE...], where REGEXP is a Perl 5 regular expression (see perlre(1)). This finds all <programme> elements containing text matching the regexp. The channels are left unchanged, that is, all the <channel> elements are output.

For more advanced searches, you can specify a Boolean expression (which loosely follows the style of find(1)). There are many tests for matching programme content against a regular expression, a few for matching channels and programmes on those channels, and a few special tests.

OPTIONS

--output FILE write to FILE rather than standard output.

--ignore-case, -i treat all regular expression matches as case insensitive.

EXPRESSIONS

PROGRAMME CONTENT TESTS

The tests for programme content match against particular attributes or subelements of the <programme> element in the XML data. Each test is named the same as the attribute or element it matches. Those which take a regexp as an argument match if the programme contains at least one attribute or element of the same name whose content matches the regexp. Those which do not take a regexp match if the programme simply contains one or more attributes or elements of that name.

Some elements may or may not have content - they may just be empty. The regular expression '' (the empty string) matches any element, even one with empty content, while a nonempty regular expression matches only those with content.

For example, --desc Racing matches a programme if the programme has at least one <desc> element whose content contains 'Racing'. --stop '' (the second argument is the empty string) matches a programme if the programme gives a stop time.

There are some elements where only yes/no matching is possible, where you cannot give a regexp to query the element's content. For these the second '' argument is mandatory. For example --previously-shown '' will match programmes which have that element, but a test of --previously-shown foo will give an error because querying the content of previously-shown is not implemented. The additional empty-string argument is to leave room for future expansion.

The content tests are generated from the XMLTV file format. The current set of programme content tests is:

--audio ''

--category REGEXP

--channel REGEXP

--clumpidx REGEXP

--country REGEXP

--credits ''

--date REGEXP

--desc REGEXP

--episode-num ''

--icon ''

--keyword REGEXP

--language REGEXP

--last-chance REGEXP

--length ''

--new

--orig-language REGEXP

--pdc-start REGEXP

--premiere REGEXP

--previously-shown ''

--rating ''

--showview REGEXP

--star-rating ''

--start REGEXP

--stop REGEXP

--sub-title REGEXP

--subtitles ''

--title REGEXP

--url REGEXP

--video ''

--videoplus REGEXP

--vps-start REGEXP

While every attribute and subelement of <programme> elements is included in the above list, for some of them it is normally more convenient to use the special tests described below.

CHANNEL TESTS

There are two tests for channels. These filter both <programme> and <channel> elements: if a channel is filtered out then all programmes on that channel are too.

--channel-name REGEXP True if the channel has a <name> whose content matches REGEXP.

--channel-id CHANNEL_ID True if the channel's XMLTV id is exactly equal to CHANNEL_ID.

TIME TESTS

Normally you don't want to test time strings with a regular expression but rather compare them with some other time. There are two tests for this.

--on-after DATE True if the programme will be broadcast at or after DATE, or will be part of the way through broadcasting at DATE. (Note: a programme is considered to be broadcasting from its start time, up to but not including its stop time.) DATE can be given in any sane date format; but if you don't specify the timezone then UTC is assumed. To remove all the programmes you have already missed, try --on-after now.

--on-before DATE True if the programme will be broadcast wholly before DATE, or if it will be part of the way through broadcasting at DATE. To remove all the programmes that haven't yet begun broadcasting, try --on-before now. You can use --on-before and --on-after together to find all programmes which are broadcasting at a certain time.

Another way of thinking about these two tests is that --on-after now gives 'all programmes you could possibly still watch, although perhaps only catching the end'. --on-before now gives 'all programmes you could possibly have seen, even if only the start'.

--eval CODE Evaluate CODE as Perl code, use the return value to decide whether to keep the programme. The Perl code will be given the programme data in $_ in XMLTV.pm hash format (see XMLTV). The code can actually modify the programme passed in, which can be used for quick fixups. This option is not intended for normal use, but as an escape in case none of the existing tests is what you want. If you develop any useful bits of code, please submit them to be included as new tests.

LOGICAL OPERATORS

EXPR1 --and EXPR2, EXPR1 -and EXPR2, EXPR1 EXPR2

EXPR1 --or EXPR2, EXPR1 -or EXPR2

--not EXPR, -not EXPR, ! EXPR

Of these, 'not' binds tightest, affecting the following predicate only. 'and' is next, and 'or' binds loosest.

AUTHOR

Ed Avis, [email protected]