3 derp \- directory-examining recursive compare
17 recursively compares the two directories
21 using a third common backup directory
23 as reference. The changes found are printed
24 to standard output, one per line, with the file
25 status describing either sides actions followed
26 by tabulator and the relative file path which might
27 be empty in case when the changed files refers to the
28 ones given at program arguments.
30 The possible status codes:
41 Both sides added different files with the
53 File was changed differently in
78 Errors are printed to standard error unless
80 option is specified. The program is terminated
81 when errors are encountered unless the
83 option is given. This can be useful if files
84 are not accessible due to file permission or
89 option will consider changes of file owner and group.
90 When omitted, file ownership is ignored.
94 option sets the octal mask
96 of bits to check in the file permissions. The default
97 ignores file permissions.
99 When modification times are comparable then the
101 option can be used to quickly find changes. If specified,
102 files are considered unchanged if the name, file size and
103 the modification time matches. This is useful when
104 comparing /n/dump archives on the same fileserver.
106 Files are considered the same if they are from the
111 matches. For directories, the access time is also
112 compared. If the access time was disabled on the
113 fileserver, then all directories need to be compared
118 Some filesystems like
120 do not always return exact file size in stat, so
121 the length check can be disabled with the
125 .B /sys/src/cmd/derp.c
133 The exit status is set to 'errors' when
134 errors were encountered.
137 first appeared in 9front (November, 2012).