term% cat index.txt DERP(1) General Commands Manual 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 de‐
scribing 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 use‐
ful 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).
DERP(1)