---
name: "ident"
section: "1"
platform: "linux"
package: "rcs"
version: "5.10.1-3"
release: "Arch Linux 2026-11-01"
platforms: ["linux", "freebsd", "openbsd"]
url: "https://new.carta.tech/ident"
---

# ident(1)

identify RCS keyword strings in files

## 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 RCS command [**co**(1)](/co/1.md), 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 RCS'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 \<stdio.h\>**\
   **static char const rcsid\[\] =**\
  \
     **"$Id: f.c,v 5.4 1993/11/09 17:40:15 eggert Exp $";**\
   **int main() { return printf("%s\\n", 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 5.4 1993/11/09 17:40:15 eggert Exp $** **f.o:**\
       **$Id: f.c,v 5.4 1993/11/09 17:40:15 eggert Exp $**

If a C program defines a string like **rcsid** above but does not use it, [**lint**(1)](/lint/1.md) 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 RCS-supported keyword. This gives you information about nonstandard keywords like **$XConsortium$**.

The pattern normally requires a colon and a space immediately after the keyword and a space immediately before the terminating **$**, but for Subversion 1.2 (and later) compatibility, **ident** will also recognize the pattern **$***keyword***::** *text* **$** (i.e., two colons and a space) and the pattern **$***keyword***::** *text #***$** (likewise, with a hash before the terminating **$**). These are the fixed-width keyword syntax. To summarize, the three recognized patterns are:

-

  **$***keyword***:** *text* **$**\
   **$***keyword***::** *text* **$**\
   **$***keyword***::** *text #***$**\

## KEYWORDS

Here is the list of keywords currently maintained by [**co**(1)](/co/1.md). All times are given in Coordinated Universal Time (UTC, sometimes called GMT) by default, but if the files were checked out with **co**'s **-z***zone* 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 RCS file name, the revision number, the date and time, the author, the state, and the locker (if locked).

- **$Id$**

  Same as **$Header$**, except that the RCS file name is without directory components.

- **$Locker$**

  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 RCS file name without directory components.

- **$Revision$**

  The revision number assigned to the revision.

- **$Source$**

  The full RCS file name.

- **$State$**

  The state assigned to the revision with the **-s** option of [**rcs**(1)](/rcs/1.md) or [**ci**(1)](/ci/1.md).

[**co**(1)](/co/1.md) 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: 5.10.1; Release Date: 2022-02-03.\
 Copyright © 2010-2022 Thien-Thi Nguyen.\
 Copyright © 1990, 1992, 1993 Paul Eggert.\
 Copyright © 1982, 1988, 1989 Walter F. Tichy.\

## SEE ALSO

[**ci**(1)](/ci/1.md), [**co**(1)](/co/1.md), [**rcs**(1)](/rcs/1.md), [**rcsdiff**(1)](/rcsdiff/1.md), [**rcsmerge**(1)](/rcsmerge/1.md), [**rlog**(1)](/rlog/1.md), [**rcsfile**(5)](/rcsfile/5.md).

Walter F. Tichy, RCS--A System for Version Control, *Software--Practice & Experience* **15**, 7 (July 1985), 637-654.

The full documentation for RCS is maintained as a Texinfo manual. If the [**info**(1)](/info/1.md) and RCS programs are properly installed at your site, the command

-

  **info rcs**

should give you access to the complete manual. Additionally, the RCS homepage:

-

  **http://www.gnu.org/software/rcs/**

has news and links to the latest release, development site, etc.