Add support for expanding to match language files.

We can expand the language names to match the extensions and the
magic recognition for those files. This means than many definitions
become a lot easier to set, as we may just specify which language
files to match.

common

@@ -83,19 +83,80 @@ function config() {
 ##
 # Expand a set of filenames from wildcards.
 #
+# This can be either:
+#   * A wildcarded filename in shell style.
+#     Examples: *.py foo/*.py
+#
+#   * A language name in braces to restrict to that type, followed by a directory to search within
+#     Examples: {python} {python}foo
+#
 # @param $@     filenames with wildcards
+#
+# @return filename per line on stdout
 function expand_filenames() {
-    (
-        # If nothing matches a wildcard string, return empty
-        shopt -s nullglob
+    local specs="$*"
+    local lang=''
+    local dir=''
+    local exts
+    local magic
+    local find_match
+    local spec
+
+    for spec in $specs ; do
+        if [[ "${spec:0:1}" == '{' ]] ; then
+            # This is a language specification
+            lang="${spec:1}"
+            lang="${lang%%\}*}"
+            dir="${spec#*\}}"
+            exts="$(call_if_function "${lang}_match_extensions")"
+            magic="$(call_if_function "${lang}_match_magic")"
+
+            # Construct the specification for find
+            find_match=()
+            for ext in $exts ; do
+                if [[ "${#find_match[@]}" != '0' ]] ; then
+                    find_match+=('-o')
+                fi
+                find_match+=('-name' "*.$ext")
+            done
+
+            # List all the requested extensions
+            if [[ "${#find_match[@]}" != '0' ]] ; then
+                find "./$dir" -type f "${find_match[@]}" \
+                    | (grep -E -v '(/\.|^\.//*ci/)' || true)
+            fi
+
+            # List all the files matching requested magic
+            if [[ "${magic}" != '' ]] ; then
+                if [[ "${#find_match[@]}" != '0' ]] ; then
+                    find_match=('!' '(' "${find_match[@]}" ')')
+                else
+                    find_match=()
+                fi
 
-        # Note: Cannot use 'shopt -s globstar' to allow '**' to be subdirectory match.
-        #       It isn't supported on OSX.
+                # Find files that do not match the extensions, are not in the
+                # special or hidden directories, and which match the magic
+                # output.
+                find "./$dir" -type f -size -100k "${find_match[@]}" -print0 \
+                    | (grep -E -Z -z -v '(/\.|^\.//*ci/)' || true) \
+                    | xargs -0 file -N -n -F':::' /dev/null \
+                    | sed -E "/${magic}/! d; s/::: .*//"
+            fi
+        else
+            (
+                # If nothing matches a wildcard string, return empty
+                shopt -s nullglob
 
-        eval echo "$*"
-    )
+                # Note: Cannot use 'shopt -s globstar' to allow '**' to be subdirectory match.
+                #       It isn't supported on OSX.
+
+                eval echo "$spec"
+            )
+        fi
+    done | sed '/^$/d ; s!//*!/!g ; s!^\./!!' | sort -u
 }
 
+
 ##
 # Find the tool configuration for a given action.
 #

common.perl

@@ -46,6 +46,16 @@ function perl_active() {
 }
 
 
+##
+# Matching functions for filename expansion.
+function perl_match_magic() {
+    echo -n 'Perl script'
+}
+function perl_match_extensions() {
+    echo -n 'pl pm'
+}
+
+
 ##
 # Help messages
 function perl_help_lint() {

common.python

@@ -94,6 +94,16 @@ function python_active() {
 }
 
 
+##
+# Matching functions for filename expansion.
+function python_match_magic() {
+    echo -n 'Python script'
+}
+function python_match_extensions() {
+    echo -n 'py'
+}
+
+
 ##
 # Help messages
 function python_help_any() {