REDO-WHICHDO(1)

NAME
redo-whichdo - show redo's search path for a .do file

SYNOPSIS
redo-whichdo <target>

DESCRIPTION
redo(1) and redo-ifchange(1) build their targets by executing a ".do file" script with appropriate arguments. .do files are searched starting from the directory containing the target, and if not found there, up the directory tree until a match is found.

To help debugging your scripts when redo is using an unexpected .do file, or to write advanced scripts that "proxy" from one .do file to another, you can use redo-whichdo to see the exact search path that redo uses.

The output format lists potential .do files, one per line, in order of preference, separated by newline characters, and stopping once a matching .do file has been found. If the return code is zero, the last line is a .do file that actually exists; otherwise the entire search path has been exhausted (and printed).

EXAMPLE
Here's a typical search path for a source file (x/y/a.b.o). Because the filename contains two dots (.), at each level of the hierarchy, redo needs to search default.b.o.do, default.o.do, and default.do. ```sh $ redo-whichdo x/y/a.b.o; echo $?

        x/y/a.b.o.do
        x/y/default.b.o.do
        x/y/default.o.do
        x/y/default.do
        x/default.b.o.do
        x/default.o.do
        x/default.do
        default.b.o.do
        default.o.do
        0

`` You might useredo-whichdoto delegate from one .do script to another, using code like the following. This gets a little tricky because not only are you finding a new .do file, but you havecdto the .do file directory and adjust$1and$2` appropriately.

        ofile=$PWD/$3
        x1=$1
        cd "$SRCDIR"
        redo-whichdo "$x1" | {
            ifcreate=
            while read dopath; do
                if [ ! -e "$dopath" ]; then
                    ifcreate="$ifcreate $dopath"
                else
                    redo-ifcreate $ifcreate
                    redo-ifchange "$dopath"
                    dofile=${dopath##*/}
                    dodir=${dopath%$dofile}
                    # Create updated $1 and $2 for the new .do file
                    x1_rel=${x1#$dodir}
                    ext=${dofile##*default}
                    if [ "$ext" != "$dofile" ]; then
                        ext=${ext%.do}
                    else
                        ext=''
                    fi
                    x2_rel=${x1#$dodir}
                    x2_rel=${x2_rel%$ext}
                    cd "$dodir"
                    set -- "$x1_rel" "$x2_rel" "$ofile"
                    . "./$dofile"
                    exit
                fi
            done
            exit 3
        }

REDO
Part of the redo(1) suite.

CREDITS
The original concept for redo was created by D. J. Bernstein and documented on his web site (http://cr.yp.to/redo.html). This independent implementation was created by Avery Pennarun and you can find its source code at http://github.com/apenwarr/redo.

SEE ALSO
redo(1), redo-ifchange(1), redo-ifcreate(1)

AUTHOR
Avery Pennarun <apenwarr@gmail.com>