NUM = getfilenum (NAME, P) returns an array of numbers indexing 
the filenames (or directory names) matching NAME from the current 
directory. The indices are searched in the strings following the 
substring P. Wildcards (*) and brackets ([], see rdir) may be used 
in NAME, including in intermediate pathnames. 
 
NUM = getfilenum (NAME, P, OPT), where OPT is 'dironly', 'fileonly' or 
'filedir', gets the numbers only from the directory names, file names, 
or both (by default), respectively. 
 

 
 
  If the files 'B01_t12.vec','B02_t18.vec', 'B03_t24.vec' are present 
  in the current directory, 
     getfilenum ('*.vec', '_t')   returns [12 18 24], 
     getfilenum ('*.vec', 'B')    returns [1 2 3]. 
 
  n=getfilenum('*/*.JPG','DSC') returns the indices of all the files 
  matching 'DSCxxx.JPG' in all directories. 
 

rdir, renumberfile.