Rdproto reads and interprets the named proto file relative to
the root directory root.
Each line of the proto file specifies a file to copy. Blank lines
and lines beginning with # are ignored. Indentation (usually tabs)
is significant, with each level of indentation corresponding to
a level in the file tree. Fields within a line are separated by
white space. The first field is the last path element in the destination
file tree. The second field specifies the permissions. The third
field is the owner of the file, and the fourth is the group owning
the file. The fifth field is the name of the file from which to
copy; this file is read from the current name space, not the source
file tree. All fields except the first are optional. Specifying
permissions, owner, or group causes rdproto to fetch the corresponding
information from the file rather than override it. (This is the
default behavior when the fields are not present; explicitly specifying
– is useful when one wishes to set, say, the file owner without
setting the permissions.)
Names beginning with a $ are expanded as environment variables.
If the first file specified in a directory is *, all of the files
in that directory are considered listed. If the first file is
+, all of the files are copied, and all subdirectories are recursively
considered listed. All files are considered relative to root.
For each file named by the proto, enm is called with new pointing
at the name of the file (without the root prefix), old pointing
at the name of the source file (with the root prefix, when applicable),
and Dir at the desired directory information for the new file.
Only the name, uid, gid, mode, mtime, and length fields
are guaranteed to be valid. The argument a is the same argument
passed to rdproto; typically it points at some extra state used
by the enumeration function.
When files or directories do not exist or cannot be read by rdproto,
it formats a warning message, calls warn, and continues processing;
if warn is nil, rdproto prints the warning message to standard
Rdproto returns zero if proto was processed, –1 if it could not