5 \fBbackup\fR [\fB\-djmnorstvz\fR] \fIdir1 dir2\fR
20 # At top level, only directories are backed up
23 # Do not copy junk: \fI *.Z, *.bak, a.out, core\fR, etc
26 # If device full, prompt for new diskette
29 # Do not backup top-level directories
32 # Do not copy \fI*.o\fR files
38 # Do not copy \fI*.s\fR files
41 # Preserve creation times
44 # Verbose; list files being backed up
47 # Compress the files on the backup medium
51 # Backup current directory compressed
53 .B backup /bin /usr/bin
54 # Backup bin from RAM disk to hard disk
57 \fIBackup\fR (recursively) backs up the contents of a given directory and its
58 subdirectories to another part of the file system.
59 It has two typical uses.
60 First, some portion of the file system can be backed up onto 1 or more
62 When a diskette fills up, the user is prompted for a new one.
63 The backups are in the form of mountable file systems.
64 Second, a directory on RAM disk can be backed up onto hard disk.
65 If the target directory is empty, the entire source directory is copied
66 there, optionally compressed to save space.
67 If the target directory is an old backup, only those files in the target
68 directory that are older than similar names in the source directory are
70 \fIBackup\fR uses times for this purpose, like \fImake\fR.
71 Calling \fIBackup\fR as \fIRestore\fR is equivalent to using the -r option;
72 this replaces newer files in the target directory with older files from the
73 source directory, uncompressing them if necessary. The target directory
74 contents are thus returned to some previous state.