DERP(1)DERP(1)
NAME
derp – directory-examining recursive compare
SYNOPSIS
derp
[
-qcutDL
] [
-p
perms
]
myfile
oldfile
yourfile
DESCRIPTION
Derp
recursively compares the two directories
myfile
and
yourfile
using a third common backup directory
oldfile
as reference. The changes found are printed
to standard output, one per line, with the file
status describing either sides actions followed
by tabulator and the relative file path which might
be empty in case when the changed files refers to the
ones given at program arguments.
The possible status codes:
an
File added in
myfile
na
File added in
yourfile
aa!
Both sides added different files with the
same name
mn
File was modified in
myfile
nm
File was modified in
yourfile
mm!
File was changed differently in
myfile
and
yourfile
dn
File was deleted in
myfile
nd
File was deleted in
yourfile
md!
File was modified in
myfile
but deleted in
yourfile
dm!
File was modified in
yourfile
but deleted in
myfile
Errors are printed to standard error unless
-q
option is specified. The program is terminated
when errors are encountered unless the
-c
option is given. This can be useful if files
are not accessible due to file permission or
media corruption.
The
-u
option will consider changes of file owner and group.
When omitted, file ownership is ignored.
The
-p
option sets the octal mask
perms
of bits to check in the file permissions. The default
ignores file permissions.
When modification times are comparable then the
-t
option can be used to quickly find changes. If specified,
files are considered unchanged if the name, file size and
the modification time matches. This is useful when
comparing /n/dump archives on the same fileserver.
Files are considered the same if they are from the
same mount and their
qid
(see
stat(5))
matches. For directories, the access time is also
compared. If the access time was disabled on the
fileserver, then all directories need to be compared
using the
-D
option.
Some filesystems like
hgfs(4)
do not always return exact file size in stat, so
the length check can be disabled with the
-L
option.
SOURCE
/sys/src/cmd/derp.c
SEE ALSO
cmp(1),
diff(1),
history(1),
fs(4),
hgfs(4)
DIAGNOSTICS
The exit status is set to ’errors’ when
errors were encountered.
HISTORY
Derp
first appeared in 9front (November, 2012).