.de URL
\\$2 \(laURL: \\$1 \(ra\\$3
..
.if \n[.g] .mso www.tmac
.TH REDO-WHICHDO 1
.SH NAME
redo-whichdo \- print search paths for dofiles to build a
.I redo
target
.SH SYNOPSIS
.B redo-whichdo
.I target
.SH DESCRIPTION
.I redo(1)
is a tool for building files and for rebuilding them if any of their dependencies have changed.
.I redo-whichdo
prints all dofiles that
.I redo(1)
will look for to build the target.
If the exit code of
.I redo-whichdo
indicates success, the last filename is the filename of the dofile that
.I redo(1)
will actually use to build the target.
.PP
.I redo-whichdo
prints the filename for a dofile that
.I redo(1)
could use to build the target.
If the dofile exists,
.I redo-whichdo
exits with a status code indicating success.
If the dofile does not exist,
.I redo-whichdo
either repeats the previous action with a fallback filename or exits with a status code indicating error if
.I redo-whichdo
can not find a dofile to build the target.
.PP
If standard output is a terminal,
.I redo-whichdo
separates filenames by newline characters. Otherwise,
.I redo-whichdo
separates filenames by null characters.
Shell scripts that act on the output of
.I redo-whichdo
can pipe it to
.I xargs(1)
invoked with the
.B -0
option to handle the filenames.
.SH EXAMPLES
.PP
Consider a root directory containing only the three dofiles
.IR a.do ,
.IR default.b.do ,
.IR default.c.do ,
and a folder
.IR d .
For the targets,
.IR a ,
.IR a.b ,
and
.IR a.b.c ,
.IR d/a.b.c ,
the output of
.I redo-whichdo(1)
would be these:
.TP
.I a
.br
/a.do
.TP
.I a.b
.br
/a.b.do
.br
/default.b.do
.TP
.I a.b.c
.br
/a.b.c.do
.br
/default.b.c.do
.br
/default.c.do
.TP
.I d/a.b.c
.br
/d/a.b.c.do
.br
/d/default.b.c.do
.br
/d/default.c.do
.br
/d/default.do
.br
/default.b.c.do
.br
/default.c.do
.SH NOTES
.PP
A dofile used to build a target is a dependency of that target:
If
.I redo(1)
determines that the dofile used to build a target has changed, the target will be rebuilt.
.PP
All non-existent dofiles searched for while building a target are non-existence dependencies of that target:
If
.I redo(1)
finds that a previously searched for non-existent dofile exists, the target will be rebuilt.
.SH HISTORY
.I redo-whichdo
was designed by Avery Pennarun and Nils Dagsson Moskopp as part of Avery Pennarun's
.I redo
implementation and independently implemented by Nils Dagsson Moskopp.
.SH AUTHOR
.I redo-whichdo
and this man page were written by Nils Dagsson Moskopp.
.SH COPYRIGHT
Copyright © 2018-2019 Nils Dagsson Moskopp.
License AGPLv3+: GNU Affero GPL version 3 or later <http://www.gnu.org/licenses/agpl-3.0.html>.
This is free software: you are free to change and redistribute it. There is NO WARRANTY, to the extent permitted by law.
.SH SEE ALSO
.IR redo(1) ,
.IR redo-ifchange(1) ,
.IR redo-ifcreate(1) ,
.IR redo-targets(1)