identd Linux Service

identd service:

Identification through TCP connection. It returns user information to a remote host that a user is requesting a service from.
Now lets see the manual of identd service.
Manual identd:
Name
ident - identify RCS keyword strings in files
Synopsis
ident [ -q ] [ -V ] [ file ... ]
Description
ident searches for all instances of the pattern $keyword: text $ in the named files or, if no files are named, the standard input.
These patterns are normally inserted automatically by the command co(1), but can also be inserted manually. The option -q suppresses the warning given if there are no patterns in a file. The option -V prints ident's version number.
ident works on text files as well as object files and dumps. For example, if the C program in f.c contains
#include
static char const rcsid[] =
"$Id: f.c,v $";
int main() { return printf("%s ", rcsid) == EOF; }
and f.c is compiled into f.o, then the command
ident f.c f.o
will output
f.c: $Id: f.c,v $f.o: $Id: f.c,v $If a C program defines a string like
rcsid above but does not use it, lint(1) may complain, and some C compilers will optimize away the string. The most reliable solution is to have the program use the rcsid string, as shown in the example above.
ident finds all instances of the $keyword: text $ pattern, even if keyword is not actually an -supported keyword. This gives you information about nonstandard keywords like $XConsortium$.
Keywords
Here is the list of keywords currently maintained by co(1). All times are given in Coordinated Universal Time (, sometimes called GMT ) by default, but if the files were checked out with co's -zzone option, times are given with a numeric time zone indication appended.
$Author$
The login name of the user who checked in the revision.
$Date$
The date and time the revision was checked in.
$Header$
A standard header containing the full pathname of the file, the revision number, the date and time, the author, the state, and the locker (if locked).
$Id$
Same as $Header$, except that the filename is without a path.
$Locker$
The login name of the user who locked the revision (empty if not locked).
$Log$
The log message supplied during checkin. For ident's purposes, this is equivalent to $RCSfile$.
$Name$
The symbolic name used to check out the revision, if any.
$RCSfile$
The name of the file without a path.
$Revision$
The revision number assigned to the revision.
$Source$
The full pathname of the file.
$State$
The state assigned to the revision with the -s option of rcs(1) or ci(1).
co(1) represents the following characters in keyword values by escape sequences to keep keyword strings well-formed.

char    escape sequence
tab        \t
newline    \n
space      \040
$          \044
\          \\

Identification
Author: Walter F. Tichy.
Manual Page Revision: ; Release Date: .
Copyright © 1982, 1988, 1989 Walter F. Tichy.
Copyright © 1990, 1992, 1993 Paul Eggert.
See Also
ci(1), co(1), rcs(1), rcsdiff(1), rcsintro(1), rcsmerge(1), rlog(1), rcsfile(5)
Walter F. Tichy, A System for Version Control, SoftwarePractice & Experience 15, 7 (July 1985), 637-654.
REFERENCED BY
cvs(1), netcdf(3), netcdf_f77(3), netcdf_f90(3), rcsclean(1)