DOS BAT file equivalent to Unix basename command?

To expand on hobodave's and ars's answers, here's the relevant snippet of help from the for command:

In addition, substitution of FOR variable references has been enhanced.
You can now use the following optional syntax:

    %~I         - expands %I removing any surrounding quotes (")
    %~fI        - expands %I to a fully qualified path name
    %~dI        - expands %I to a drive letter only
    %~pI        - expands %I to a path only
    %~nI        - expands %I to a file name only
    %~xI        - expands %I to a file extension only
    %~sI        - expanded path contains short names only
    %~aI        - expands %I to file attributes of file
    %~tI        - expands %I to date/time of file
    %~zI        - expands %I to size of file
    %~$PATH:I   - searches the directories listed in the PATH
                   environment variable and expands %I to the
                   fully qualified name of the first one found.
                   If the environment variable name is not
                   defined or the file is not found by the
                   search, then this modifier expands to the
                   empty string

The modifiers can be combined to get compound results:

    %~dpI       - expands %I to a drive letter and path only
    %~nxI       - expands %I to a file name and extension only
    %~fsI       - expands %I to a full path name with short names only
    %~dp$PATH:I - searches the directories listed in the PATH
                   environment variable for %I and expands to the
                   drive letter and path of the first one found.
    %~ftzaI     - expands %I to a DIR like output line

In the above examples %I and PATH can be replaced by other valid
values.  The %~ syntax is terminated by a valid FOR variable name.
Picking upper case variable names like %I makes it more readable and
avoids confusion with the modifiers, which are not case sensitive.

I understand that the answer "you can't" is not good enough. So, if it really /has/ to be done in Real Mode DOS, then get the 4DOS command shell and accompanying programs and use it instead of COMMAND.COM

http://www.4dos.info/v4dos.htm

I haven't used it in years, but it was always /far/ better than COMMAND.COM If you search this page: http://www.4dos.info/4batfaq.htm for "basename" you will see there is a Real Mode DOS answer to your problem if using 4DOS /instead/ of COMMAND.COM

The only other solution path I can think of is to find or write a Real Mode .exe that performs basename.

COMMAND.COM, even in DOS 6.22 with all its supporting external commands, was always an incredibly crippled system for scripts/batch files. Note that the MinGW32 command line progs will be of no help. All that stuff is for Protected Mode (32 bit Windows). If you try it in DOS you'll just get the cryptic "This program cannot be run in DOS mode." or something similar.

For command-line

for /F %i in ("c:\foo\bar.txt") do @echo %~ni

For .bat Files

for /F %%i in ("c:\foo\bar.txt") do @echo %%~ni

output: bar

If the path contains a space, add in "delims=" like so:

for /F "delims=" %i in ("c:\foo\bar baz.txt") do @echo %~ni

output: bar baz

(Further Reading: http://www.computerhope.com/forhlp.htm )