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 encoun-
tered 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
DERP(1) DERP(1)
can be used to quickly find changes. If specified, files are
considered unchanged if the name, file size and the modifi-
cation 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 encoun-
tered.
HISTORY
Derp first appeared in 9front (November, 2012).