How to rename some file of same pattern in shell scripting

Question

I want to write a code is shell scripting which will rename all the files of extension .txt in a current directory to extension .c .Suppose my current directory contains some 10

Answer 1

for f in *.txt; do echo mv "$f" "${f%.txt}.c"; done

Remove "echo" when you're satisfied it's working. See the bash manual for the meaning of "%" here.