mime - MIME library used within vile via perl interface
readmc *prog, *flag, @mailcaps; readmt *type, *desc, @mimetypes; mime "filename";
This library is written with a view to provide file type recognition capability to perl extensions written for vile and to open the appropriate application for viewing that file. It consists of three functions currently.
The "readmc" function reads the mailcap files provided as a list with the arguments, parses the files in that order and puts the results in the two global hashes keyed on the mime type, also passed with the arguments. The "prog" hash contains the application to invoke to view that file while the "flag" hash contains any flags provided for that mime-type in the mailcap file. The flags are used to recognize whether a plugin should be used to view the file or an external application should be used, as with netscape.
The "readmt" function reads the mime.types files provided as a list with the arguments, parses the files in that order and puts the results in the two global hashes keyed on the extension. The "type" hash contains which mime type does that extension belong to and the "desc" hash contains the description of the file type with that extension.
Both the above functions also keep a timestamp of last time each file was read and re-reads that file on re-invocation, only if it has changed since last read. This may not be required, but I left this in anyway since it might come in handy in certain situations since "mime" function calls the above routines with every invocation.
Finally, the "mime" function takes path to a file as an argument. If the absolute path is not provided, the path is assumed to be relative to the current directory (duh!). It uses the MAILCAP and MIMETYPES environment variables to figure out the appropriate plugin or application to invoke (in that order) depending on the file extension. The mime settings in files provided in MAILCAP and MIMETYPES environment variables can be overridden in the ~/.vile/mailcap and ~/.vile/mime.types files. The default action currently is to simply open the file in vile (maybe a more correct way would be to have a new plugin for displaying the file in vile attributed to the "*/*" mime type, but oh well...).
In case, the library decides that a plugin should be used to view the file, it simply calls the function provided as the plugin with the complete path to the file as the argument. The function should belong to the plugins package.
A sample plugin script for .gz files is provided along with this. Sample ~/.vile/mailcap and ~/.vile/mime.types files are also provided along with this script.
The mime parsing is not fully (or even partially?) RFC compliant. I have written this library by simply going through all the mailcap and mime.types files I found on my system. It works most satisfactorily for me and it should for anyone else, but I cannot guarantee anything.
The library recognizes wildcards in mime types to some extent. Which means if it cannot find a plugin or application to use for "image/gif", it will look for plugin or application for "image/*", then for "*/*" and finally for "*" mime type. But it will not honor wildcards of the format "ima*/gif" or "image/g*" (and I dont even know if the RFC allows such wildcards in mime types).
The library currently does not support the mailcap and mime.types files in the system-wide vile directory (where the help file resides).
MAILCAP contains the list of mailcap files to use in the proper order
MIMETYPES contains the list of mime type files to use in the proper order
J. Chris Coppick, once wrote: Having a Perl interpreter in vile is very slick. Kudos to everyone who made it happen.
Kuntal Daftary writes: Amen!
Kuntal Daftary (email@example.com), 1998