You can use
du, to report on the size of directories or files, but when my file is smaller than the block size I don’t see the output I expect.
With a small file, this should be the size of the number of characters.
$ echo 'Every Good Boy Deserves Fudge' > staff.txt
$ cat staff.txt | wc -c
But when I use
du to examine file, I don’t see 30.
$ du -h staff.txt
du measures in block sizes because in general if any part of a block is used, then for the purposes of the operating system the entire block is used.
You can tell
du to care only about the size of the file with
--apparent-size which is only apparent because between the beginning and end of the file the OS can’t tell which bytes are in use or are not in use.
$ du --apparent-size staff.txt
When reporting apparent size it rounds up to kilobytes, or
To get the actual size of the file, you can use
-b which is the same as
$ du -b staff.txt