REF REF
NAME
ref - Display a C function header
SYNOPSIS
ref [-t] [-c class]... [-f file]... tag
DESCRIPTION
ref quickly locates and displays the header of a function.
To do this, ref looks in the "tags" file for the line that
describes the function, and then scans the source file for
the function. When it locates the function, it displays an
introductory comment (if there is one), the function's
declaration, and the declarations of all arguments.
SEARCH METHOD
ref uses a fairly sophisticated tag look-up algorithm. If
you supply a filename via -f file, then elvis first scans
the tags file for a static tag from that file. This search
is limited to the tags file in the current directory.
If you supply a classname via -c class, then elvis searches
for a tag from that class. This search is not limited to
the current directory; You can supply a list of directories
in the environment variable TAGPATH, and ref will search
through the "tags" file in each directory until it finds a
tag in the desired class.
If that fails, ref will then try to look up an ordinary
global tag. This search checks all of the directories
listed in TAGPATH, too.
If you've given the -t flag, then ref will simply output the
tag line that it found, and then exit. Without -t, though,
ref will search for the tag line. It will try to open the
source file, which should be in the same directory as the
tags file where the tag was discovered. If the source file
doesn't exist, or is unreadable, then ref will try to open a
file called "refs" in that directory. Either way, ref will
try to locate the tag, and display whatever it finds.
INTERACTION WITH ELVIS
ref is used by elvis' shift-K command. If the cursor is
located on a word such as "splat", in the file "foo.c", then
elvis will invoke ref with the command "ref -f foo.c splat".
If elvis has been compiled with the -DEXTERNAL_TAGS flag,
then elvis will use ref to scan the tags files. This is
slower than the built-in tag searching, but it allows elvis
to access the more sophisticated tag lookup provided by ref.
Other than that, external tags should act exactly like
internal tags.
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REF REF
OPTIONS
-t Output tag info, instead of the function header.
-f file
The tag might be a static function in file. You can
use several -f flags to have ref consider static tags
from more than one file.
-c class
The tag might be a member of class class. You can use
several -c flags to have ref consider tags from more
than one class.
FILES
tags List of function names and their locations, generated
by ctags.
refs Function headers extracted from source files
(optional).
ENVIRONMENT
TAGPATH
List of directories to be searched. The elements in
the list are separated by either semicolons (for MS-
DOS, Atari TOS, and AmigaDos), or by colons (every
other operating system). For each operating system,
ref has a built-in default which is probably adequate.
NOTES
You might want to generate a "tags" file the directory that
contains the source code for standard C library on your
system. If licensing restrictions prevent you from making
the library source readable by everybody, then you can have
ctags generate a "refs" file, and make "refs" readable by
everybody.
If your system doesn't come with the library source code,
then perhaps you can produce something workable from the
lint libraries.
SEE ALSO
elvis(1), ctags(1)
AUTHOR
Steve Kirkendall
kirkenda@cs.pdx.edu
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