How do I accomplish renaming bulky indexed files to smaller number?

How do I accomplish renaming bulky indexed files to its smaller index number, with any kind of tools ?
That is to rename

1.c -> 0.c
2.c -> 1.c
...
7.c -> 6.c
8.c -> 7.c
9.c -> 8.c
...
...
(in large numbers of files.) Thank so much in advance

I'd solve and answer mine. on Windows cmd.exe console:

cmd /v /k
for /f %x in ('dir /b ??.c') do (set/a t=%~nx-1 &ren %x !t!.c)



rename to greater number; dir in reversed and +1, i.e. use:


dir /b /o-n
t =%~nx-1


Much better is to get TCC/LE more improved and sensible cmd.exe duplicate

I'd solve and answer mine. on Windows cmd.exe console:


cmd /v /k
for /f %x in ('dir /b ??.c') do (set/a t=%~nx-1 &ren %x !t!.c)


rename to greater number; dir in reversed and +1, i.e. use:


dir /b /o-n
t =%~nx+1


Much better is to get TCC/LE more improved and sensible cmd.exe duplicate

You can also do this in PowerShell:

Code:

foreach ($file in Get-ChildItem -Filter *.c -Recurse) {
  if ($file.fullname -match '\\([0-9]+?)\.c') {
    Rename-Item $file.fullname ([string]($matches[1]-1)+'.c')
  }
}