VGRINDEFS(5)

NAME
vgrindefs - language definition data base for vgrind(1)

SYNOPSIS
vgrindefs

DESCRIPTION
The vgrindefs file contains all language definitions for vgrind(1). The data base is very similar to termcap(5).

FIELDS
The following table names and describes each field.

Name Type Description
ab | str | regular expression for the start of an alternate comment
ae | str | regular expression for the end of an alternate comment
pb | str | regular expression for start of a procedure
bb | str | regular expression for start of a lexical block
be | str | regular expression for the end of a lexical block
cb | str | regular expression for the start of a comment
ce | str | regular expression for the end of a comment
sb | str | regular expression for the start of a string
se | str | regular expression for the end of a string
lb | str | regular expression for the start of a character constant
le | str | regular expression for the end of a character constant
nc | str | regular expression for a non-comment (see below)
tl | bool | present means procedures are only defined at the top lexical level
oc | bool | present means upper and lower case are equivalent
kw | str | a list of keywords separated by spaces

Non-comments are required to describe a certain context where a sequence that would normally start a comment loses its special meaning. A typical example for this can be found in Perl, where comments are normally starting with ‘#’, while the string ‘$#’ is an operator on an array.

EXAMPLES
The following entry, which describes the C language, is typical of a language entry.

    C|c::pb=^\d?*?\d?\p\d?\(\a?\):bb={:be=}:cb=/*:ce=*/:sb=":se=\e":\
    :lb=':le=\e':tl:\
    :kw=asm auto break case char continue default do double else enum\
    extern float for fortran goto if int long register return short\
    sizeof static struct switch typedef union unsigned while #define\
    #else #endif #if #ifdef #ifndef #include #undef # define else endif\
    if ifdef ifndef include undef:

Note that the first field is just the language name (and any variants of it). Thus the C language could be specified to vgrind(1) as "c" or "C".

Entries may continue onto multiple lines by giving a \ as the last character of a line. Capabilities in vgrindefs are of two types: Boolean capabilities which indicate that the language has some particular feature and string capabilities which give a regular expression or keyword list.

REGULAR EXPRESSIONS
Vgrindefs uses regular expression which are very similar to those of ex(1) and lex(1). The characters `^', `$', `:' and `\' are reserved characters and must be "quoted" with a preceding ‘\’ if they are to be included as normal characters. The metasymbols and their meanings are:

$   the end of a line

^   the beginning of a line

\d  a delimiter (space, tab, newline, start of line)

\a  matches any string of symbols (like .* in lex)

\p  matches any alphanumeric name. In a procedure definition (pb) the string that matches this symbol is used as the procedure name.

()  grouping

|   alternation

?   last item is optional

\e  preceding any string means that the string will not match an input string if the input string is preceded by an escape character (\). This is typically used for languages (like C) which can include the string delimiter in a string by escaping it.

Unlike other regular expressions in the system, these match words and not characters. Hence something like "(tramp|steamer)flies?" would match "tramp", "steamer", "trampflies", or "steamerflies".

KEYWORD LIST
The keyword list is just a list of keywords in the language separated by spaces. If the "oc" boolean is specified, indicating that upper and lower case are equivalent, then all the keywords should be specified in lower case.

FILES
/usr/share/misc/vgrindefs
    File containing terminal descriptions.

SEE ALSO
vgrind(1), troff(1)

HISTORY
The vgrindefs file format appeared in 4.2BSD.