fastrm - quickly remove a set of files
fastrm [ -d ] [ -e ] [ -uN ] [ -sM ] [ -cI ] base_directory
Fastrm reads a list of files, one per line, from its standard input and
removes them. If a file is not an absolute pathname, it is taken
relative to the directory specified on the command line. The
base_directory parameter must be a simple absolute pathname — that is,
it must not contain any ‘‘/./’’ or ‘‘/../’’ references.
Fastrm is designed to be faster than the typical ‘‘| xargs rm’’
pipeline. For example, fastrm will usually chdir(2) into a directory
before removing files from it. If the input is sorted, this means that
most files to be removed will be simple names.
Fastrm assumes that its input is valid and that it is safe to just do
an unlink(2) call for each item to be removed. As a safety measure, if
fastrm is run by root it will first stat(2) the item to make sure that
it is not a directory before unlinking it.
-d If the ‘‘-d’’ flag is used then no files are removed. Instead a
list of the files to be removed, in debug form, is printed on
the standard output. Each line contains either the current
directory of fastrm at the time it would do the unlink, and then
the path name it would pass to unlink(2) as two fields separated
by white space and a ‘‘/’’, or the absolute path name (a single
field) of files it would unlink using the absolute path name.
-e If the ‘‘-e’’ flag is used, fastrm will treat an empty input
file (stdin) as an error. This is most useful when fastrm is
last in a pipeline after a preceding sort(1) as if the sort
fails, there will usually be no output to become input of
-u If the ‘‘-u’’ flag is used, then fastrm makes further
assumptions about its work environment; in particular, that
there are no symbolic links in the target tree. This flag also
suggests that it is probably faster to reference the path
../../../ rather than start from the root and come down.
(Note that this probably isn’t true on systems that have a namei
cache, which usually holds everything except ..). The
optional N is an integer that specifies the maximum number of
.. segments to use — paths that would use more than this
use the absolute path name (from the root) instead. If the
‘‘-u’’ flag is given without a value, ‘‘-u1’’ is assumed.
-s If the ‘‘-s’’ flag is used, then fastrm will perform the unlinks
from one directory — that is when a group of files in one
directory appear in the input consecutively — in the order that
the files appear in the directory from which they are to be
removed. The intent of this flag is that on systems that have a
per-process directory cache, finding files in the directory
should be faster. It can have smaller benefits on other
systems. The optional M is an integer that specifies the number
of files that must be going to be removed from one directory
before the files will be ordered. If the ‘‘-s’’ flag is given
without a value, ‘‘-s5’’ is assumed. When the directory
reordering is in use fastrm will avoid attempting to unlink
files that it can’t see in the directory, which can speed it
appreciably when many of the file names have already been
-c The ‘‘-c’’ flag may be given to instruct fastrm when it should
chdir(2). If the number of files to be unlinked from a
directory is at least I then fastrm will chdir and unlink the
files from in the directory. Otherwise it will build a path
relative to its current directory. If ‘‘-c’’ is given without
the optional integer I then ‘‘-c1’’ is assumed, which will cause
fastrm to always use chdir. If ‘‘-c’’ is not used at all, then
‘‘-c3’’ is assumed. Use ‘‘-c0’’ to prevent fastrm from ever
-a -r There are also ‘‘-a’’ and ‘‘-r’’ options, which do nothing at
all, except allow you to say ‘‘fastrm -usa’’ ‘‘fastrm -ussr’’ or
‘‘fastrm -user’’. These happen to often be convenient sets of
options to use.
Fastrm exits with a status of zero if there were no problems, or one if
something went wrong. Attempting to remove a file that does not exist
is not considered a problem. If the program exits with a non-zero
status, it is probably a good idea to feed the list of files into an
‘‘xargs rm’’ pipeline.
This is revision 1.3, dated 1996/10/29.