scp gives "not a regular file"
I just tested this and found at least 3 situations in which scp will return not a regular file:
- File is actually a directory
- File is a named pipe (a.k.a. FIFO)
- File is a device file
Case #1 seems most likely. If you meant to transfer an entire directory structure with scp use the -r option to indicate recursive copy.
"/home/pictures/file.fits" must name an actual filesystem object on the remote server. If it didn't, scp would have given a different error message.
I see that FITS is an image format. I suppose "/home/pictures/file.fits" is the name of a directory on the remote server, containing FITS files or something like that.
To copy a directory with scp, you have to supply the "-r" flag:
scp -r aa@aa:/home/pictures/file.fits .