On Mon, 2018-03-12 at 18:25 -0700, Rick Stevens wrote: > On 03/12/2018 03:37 PM, Patrick O'Callaghan wrote: > > On Tue, 2018-03-13 at 07:26 +1100, Stephen Morris wrote: > > > > 'du' with no parameters recursively lists all the subdirectories and > > > > their sizes, along with the grand total. When applied to my home > > > > directory, I get over 30,000 lines of output. That's almost never what > > > > I want. My usual call is 'du -hs'. > > > > > > > > poc > > > > > > Thanks Patrick, taking this a step further, it seems to me that the only > > > parameter for du that, to me, provides the correct file size is -b as > > > shown below. > > > > I think you have a misconception here. 'du' does not give file sizes, > > it gives disk usage. A 1-byte file takes up at least 1 disk block, so > > that's the size 'du' will give. I seem to remember that it also counts > > indirect blocks and other housekeeping that corresponds to the file > > without being included in the file's content, but I could be mistaken > > (though I'm fairly sure early versions did do that). > > du (with no flags) gives disk usage. As Patrick says, a 1-byte file > uses one disk block (which is generally 4KiB) and that's what du is > reporting (after all, "du" means "disk usage"). The "-b" flag means > "set the block size to 1 byte and show the apparent size", which is what > "ls -l" would report (there may be differences between du and ls if > sparse files are involved).
Good point about sparse files, which I'd forgotten in this context. A sparse file can be 10TB in size yet occupy only 1 disk block. 'du' will give the usage as 1 block and 'ls' will say it's 10TB. > Also, du walks down the entire current directory unless you give it > arguments to tell it what to look at. Note that the arguments you pass > it are interpreted by the _shell_, not "du" (even the man page says > "PATTERN is a shell pattern (not a regular expression)"). > > This is a common confusion point with many people. Unless you enclose > shell metacharacters in quotes (and dots and splats are metacharacters), > the shell WILL interpret them--sometimes in ways you aren't expecting! > By default, shell globbing does NOT expand filenames that start with a > dot (to the shell, a dot means "current directory"). Slight nit: '.' (on its own) means 'current directory' to the kernel, not to the Shell, i.e. it's wired into the system and doesn't depend on the command interpreter (in the same way that '/' is the path separator and cannot be changed). The use of dot-files as a way of hiding certain names is IIRC originally just a convention of 'ls' which the Shell adopted for consistency. poc _______________________________________________ users mailing list -- users@lists.fedoraproject.org To unsubscribe send an email to users-le...@lists.fedoraproject.org
