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Manual Pages  — VGRINDEFS

NAME

vgrindefs – language definition data base for vgrind(1)

CONTENTS

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 Ta Type Description

ab Ta str
regular expression for the start of an alternate comment

ae Ta str
regular expression for the end of an alternate comment

pb Ta str
regular expression for start of a procedure

bb Ta str
regular expression for start of a lexical block

be Ta str
regular expression for the end of a lexical block

cb Ta str
regular expression for the start of a comment

ce Ta str
regular expression for the end of a comment

sb Ta str
regular expression for the start of a string

se Ta str
regular expression for the end of a string

lb Ta str
regular expression for the start of a character constant

le Ta str
regular expression for the end of a character constant

nc Ta str
regular expression for a non-comment (see below)

tl Ta bool
present means procedures are only defined at the top lexical level

oc Ta bool
present means upper and lower case are equivalent

kw Ta 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.

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.

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.

SEE ALSO

troff(1), vgrind(1)

HISTORY

The vgrindefs file format appeared in BSD 4.2 .

VGRINDEFS (5) June 6, 1993

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Please direct any comments about this manual page service to Ben Bullock.

Ken Thompson was once asked by a reporter what he would have changed about Unix if he had it all to do over again. His answer: “I would spell creat with an ‘e.'”