Introduce exclusion patterns

The lsrc(1), rcup(1), and rcdn(1) commands now take any number of `-e`
flags, used to specify an exclusion pattern. This can also be controlled
via rcrc(5), the `EXCLUDES` variable.

An exclusion pattern specifies a file glob to skip. In the case of
lsrc(1), any file matching the glob is not listed; in rcup(1) it is not
symlinked; and in rcdn(1) it is not removed.

The file glob can be preceded by the name of a dotfiles directory
(separated from the file glob by a colon) to increase the specificity.

Useful for:

    rcdn -e rcrc
    rcup -d work-dotfiles -e bashrc
    rcup -d ~/.dotfiles -d wife-dotfiles -d sys-dotfiles -e wife-dotfiles:tigrc

1 files changed, 6 insertions, 1 deletions

diff --git a/bin/rcdn b/bin/rcdn
index 8695c63..66e064f 100755
--- a/bin/rcdn
+++ b/bin/rcdn
@@ -9,9 +9,11 @@ handle_command_line() {
   local version=0
   local dotfiles_dirs=
   local files=
+  local excludes=
 
-  while getopts Vqvt:d: opt; do
+  while getopts Vqve:t:d: opt; do
     case "$opt" in
+      e) excludes="$excludes $OPTARG";;
       t) arg_tags="$arg_tags $OPTARG" ;;
       v) verbosity=$(($verbosity + 1));;
       q) verbosity=$(($verbosity - 1));;
@@ -33,6 +35,9 @@ handle_command_line() {
   for dotfiles_dir in $dotfiles_dirs; do
     LS_ARGS="$LS_ARGS -d $dotfiles_dir"
   done
+  for exclude in $excludes; do
+    LS_ARGS="$LS_ARGS -e $exclude"
+  done
   LS_ARGS="$LS_ARGS $files"
 
   $DEBUG "LS_ARGS: $LS_ARGS"