Do not depend on readlink(1) or -q

Solaris 10 lacks readlink(1). Additionally, its different grep(1) and
diff(1) do not take a `-q` flag.

Use a Perl one-liner instead of readlink(1) which is missing on Solaris 10.
Also because /usr/bin/grep and diff(1) don't understand the `-q` option, make
them go quiet by redirecting stdout to `/dev/null` instead.

The Perl dependency only exists in the test suite, so it does not incur
a runtime penalty for end users.

This is to work around the fact that readlink(1) is missing on Solaris.
The tradeoff is: on Solaris, installing third-party software (readlink)
is a pain, whereas on e.g. FreeBSD installing third-party software
(Perl) is simple and common.

5 files changed, 10 insertions, 20 deletions

diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index 59d240d..31eb49b 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -57,6 +57,9 @@ The test suite uses [cram][]. It is an integration suite, meaning the
 programs are exercised from the outside and assertions are made only on
 their output or effects.
 
+The test suite requires Perl with the `Cwd` module. It expects to find Perl as
+`perl` in `$PATH`.
+
 All tests can be run like so:
 
     $ make check
diff --git a/bin/lsrc.in b/bin/lsrc.in
index 47ae889..fcf5fbe 100755
--- a/bin/lsrc.in
+++ b/bin/lsrc.in
@@ -118,7 +118,7 @@ show_file() {
     output="$output:$sigil"
   fi
 
-  if echo "$DEST_STACK:" | grep -vq ":$dest_file:"; then
+  if echo "$DEST_STACK:" | grep -v ":$dest_file:" >/dev/null; then
     DEST_STACK="$DEST_STACK:$dest_file"
     $PRINT "$output"
   else
@@ -167,7 +167,7 @@ dotfiles_dir_excludes() {
   $DEBUG "  with excludes: $excludes"
 
   for exclude in $excludes; do
-    if echo "$exclude" | grep -q ':'; then
+    if echo "$exclude" | grep ':' >/dev/null; then
       dotfiles_dir_pat="$(echo "$exclude" | sed 's/:.*//')"
       file_glob="$(echo "$exclude" | sed 's/.*://')"
 
diff --git a/bin/rcup.in b/bin/rcup.in
index f818258..bdae664 100755
--- a/bin/rcup.in
+++ b/bin/rcup.in
@@ -123,11 +123,11 @@ replace_file() {
 }
 
 is_nested() {
-  echo "$1" | sed "s:$DEST_DIR/::" | grep -q '/'
+  echo "$1" | sed "s:$DEST_DIR/::" | grep '/' >/dev/null
 }
 
 is_identical() {
-  diff -q -s "$1" "$2" > /dev/null
+  diff -c "$1" "$2" > /dev/null 2>&1
 }
 
 handle_dir() {
diff --git a/share/rcm.sh.in b/share/rcm.sh.in
index 2ce68d4..d8fc19e 100644
--- a/share/rcm.sh.in
+++ b/share/rcm.sh.in
@@ -51,7 +51,7 @@ echo_stderr() {
 }
 
 is_relative() {
-  echo "$1" | grep -vq '^/'
+  echo "$1" | grep -v '^/' >/dev/null
 }
 
 version() {
diff --git a/test/helper.sh b/test/helper.sh
index d26749c..5016cf8 100644
--- a/test/helper.sh
+++ b/test/helper.sh
@@ -35,21 +35,8 @@ refute() {
 
 resolved_path() {
   local original_path="$1"
-  local actual_path="$original_path"
-  local actual_basename="$(basename "$original_path")"
-
-  cd "$(dirname "$original_path")"
-
-  while [ -L "$actual_basename" ]; do
-    actual_path="$(readlink "$actual_basename")"
-    actual_basename="$(basename "$actual_path")"
-
-    cd "$(dirname "$actual_path")"
-  done
-
-  local current_directory="$(pwd -P)"
-
-  printf "%s/%s\n" "$current_directory" "$actual_basename"
+  perl -e \
+    "use Cwd realpath; print realpath(\"$original_path\") . \"\\n\";" 
 }
 
 assert_linked() {