if reader has used linux
then u may be knowing that when we type
a character and press tap twice the shell displays
the commands starting from those char's
is it possible to program it in unix

The bash shell allows this functionality.

Tab once will complete the filename/path if there is only one option....tab twice will list all options that meet that criteria.

Just change to bash shell.....or update your user profile to use bash. (bash is typically found in /usr/bin....but not always). If you type 'which bash' and get an answer it is in your path, and you can just use type bash to turn it on. Other than that - you may want to look at updating your .profile file to use bash.

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Pete