revdep: new version 2.0

- rewrite in C++
- much improved speed
- new feature to add non-standard library locations, see the
  man-page for details

21 files changed, 1061 insertions, 1278 deletions

diff --git a/revdep/.gitignore b/revdep/.gitignore
new file mode 100644
index 0000000..a5638af
--- /dev/null
+++ b/revdep/.gitignore
@@ -0,0 +1,2 @@
+*.o
+revdep
diff --git a/revdep/LICENSE b/revdep/LICENSE
new file mode 120000
index 0000000..d24842f
--- /dev/null
+++ b/revdep/LICENSE
@@ -0,0 +1 @@
+COPYING
\ No newline at end of file
diff --git a/revdep/Makefile b/revdep/Makefile
index f7a1050..ecae89f 100644
--- a/revdep/Makefile
+++ b/revdep/Makefile
@@ -1,34 +1,30 @@
-VERSION := 1.1
-BINDIR  := /usr/bin
-MANDIR  := /usr/man/man1
-CFLAGS  ?= -O2
-CFLAGS  += -Wall -Wextra -Wno-unused-parameter -DVERSION='"$(VERSION)"'
-LDFLAGS += -static -lz -lelf
-CC      ?= cc
-
-%.o: %.c
-	$(CC) $(CFLAGS) -c $< -o $@
-
-all: program man
-
-program: revdep
-
-man: revdep.1
-
-revdep: main.o global.o utility.o package.o
-	$(CC) $^ $(LDFLAGS) -o $@
-
-revdep.1: revdep.man
-	txt2man -t revdep $< > $@
-
-install: revdep revdep.1
+VERSION  := 2.0
+BINDIR   := /usr/bin
+MANDIR   := /usr/man/man1
+ETCDIR   := /etc/revdep.d
+CXXFLAGS ?= -O2
+CXXFLAGS += -std=gnu++0x -Wall -Wextra -g -DVERSION='"$(VERSION)"'
+LDFLAGS  += -static -lelf
+SOURCES  := elf.cpp utility.cpp main.cpp pkg.cpp elf-cache.cpp
+OBJECTS  := $(patsubst %.cpp,%.o,$(SOURCES))
+
+all: revdep revdep.1
+
+install: all
 	install -d $(DESTDIR)$(BINDIR)
 	install -d $(DESTDIR)$(MANDIR)
+	install -d $(DESTDIR)$(ETCDIR)
 	install -m 0755 revdep $(DESTDIR)$(BINDIR)/
 	install -m 0644 revdep.1 $(DESTDIR)$(MANDIR)/
 
-dist: man
-	tar --transform s:^:revdep-$(VERSION)/: -c *.c *.h *.man *.1 COPYING Makefile | xz > revdep-$(VERSION).tar.xz
+dist: revdep.1
+	git archive --format tar --prefix revdep-$(VERSION)/ HEAD | xz > revdep-$(VERSION).tar.xz
+
+revdep: $(OBJECTS)
+	$(CXX) $(OBJECTS) $(LDFLAGS) -o revdep
+
+revdep.1: revdep.man
+	txt2man revdep.man > revdep.1
 
 clean:
-	rm -f *.o revdep #revdep.1
+	$(RM) $(OBJECTS) revdep
diff --git a/revdep/TODO b/revdep/TODO
new file mode 100644
index 0000000..bd1cc25
--- /dev/null
+++ b/revdep/TODO
@@ -0,0 +1,3 @@
+Add support for NODEFLIB?
+Add support for LD_LIBRARY_PATH?
+Add support for hardware capabilility directories?
diff --git a/revdep/elf-cache.cpp b/revdep/elf-cache.cpp
new file mode 100644
index 0000000..420f41d
--- /dev/null
+++ b/revdep/elf-cache.cpp
@@ -0,0 +1,187 @@
+// Copyright (C) 2016 James Buren
+//
+// This file is part of revdep.
+//
+// revdep is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// revdep is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with revdep.  If not, see <http://www.gnu.org/licenses/>.
+
+#include "elf-cache.h"
+#include <algorithm>
+#include <limits.h>
+#include <sys/auxv.h>
+#include <libgen.h>
+
+typedef std::pair <const std::string &, Elf *> ElfPair;
+typedef std::unordered_map <std::string, Elf *>::iterator ElfIter;
+
+static void deleteElement(ElfPair pair) {
+	delete pair.second;
+}
+
+static std::string resolveDirVars(const Elf *elf, const std::string &path) {
+	static const char *lib = "lib";
+	static const char *platform = (((char *) getauxval(AT_PLATFORM)) ? : "");
+	char dir[PATH_MAX];
+
+	snprintf(dir, sizeof(dir), "%s", elf->Path().c_str());
+	dirname(dir);
+
+	struct {
+		const char *name;
+		size_t length;
+		const char *s;
+	} vars[] = {
+		{        "$LIB",  4,      lib },
+		{      "${LIB}",  6,      lib },
+		{   "$PLATFORM",  9, platform },
+		{ "${PLATFORM}", 11, platform },
+		{     "$ORIGIN",  7,      dir },
+		{   "${ORIGIN}",  9,      dir },
+		{          NULL,  0,     NULL }
+	};
+	size_t replaces;
+	std::string out = path;
+
+	do {
+		replaces = 0;
+
+		for( size_t i = 0 ; vars[i].name != NULL ; ++i ) {
+			size_t j = out.find(vars[i].name);
+
+			if(j != std::string::npos) {
+				out.replace(j, vars[i].length, vars[i].s);
+				++replaces;
+			}
+		}
+	} while(replaces > 0);
+
+	return out;
+}
+
+static StringVector resolveRunPaths(const Elf *elf, const StringVector &paths) {
+	StringVector out;
+
+	for( size_t i = 0 ; i < paths.size() ; ++i ) {
+		out.push_back(resolveDirVars(elf, paths[i]));
+	}
+
+	return out;
+}
+
+bool ElfCache::findLibraryByDirs(const Elf *elf, const std::string &lib, const StringVector &dirs) {
+	for( size_t i = 0 ; i < dirs.size() ; ++i ) {
+		std::string path = dirs[i] + "/" + lib;
+		char realPath[PATH_MAX];
+
+		if(realpath(path.c_str(), realPath) == NULL) {
+			continue;
+		}
+
+		const Elf *elf2 = LookUp(realPath);
+
+		if(elf2 == NULL) {
+			continue;
+		}
+
+		if(!elf->Compatible(elf2[0])) {
+			continue;
+		}
+
+		return true;
+	}
+
+	return false;
+}
+
+bool ElfCache::findLibraryByPath(const Elf *elf, const std::string &lib) {
+	std::string path;
+
+	if(lib[0] == '/') {
+		path = lib;
+	} else {
+		char dir[PATH_MAX];
+
+		snprintf(dir, sizeof(dir), "%s", elf->Path().c_str());
+		dirname(dir);
+
+		path = dir + ("/" + lib);
+	}
+
+	char realPath[PATH_MAX];
+
+	if(realpath(path.c_str(), realPath) == NULL) {
+		return false;
+	}
+
+	const Elf *elf2 = LookUp(realPath);
+
+	if(elf2 == NULL) {
+		return false;
+	}
+
+	return elf->Compatible(elf2[0]);
+}
+
+ElfCache::~ElfCache() {
+	std::for_each(_data.begin(), _data.end(), deleteElement);
+}
+
+const Elf *ElfCache::LookUp(const std::string &path) {
+	ElfIter value = _data.find(path);
+
+	if(value != _data.end()) {
+		return value->second;
+	}
+
+	Elf *elf = new Elf(path);
+
+	if(!elf->Valid()) {
+		delete elf;
+		return NULL;
+	}
+
+	ElfPair pair = std::make_pair <const std::string &, Elf *&> (path, elf);
+	_data.insert(pair);
+
+	return elf;
+}
+
+bool ElfCache::FindLibrary(const Elf *elf, const Package &pkg, const std::string &lib, const StringVector &dirs) {
+	if(lib.find('/') != std::string::npos) {
+		return findLibraryByPath(elf, lib);
+	}
+
+	StringVector paths;
+
+	if(elf->RunPath().size() > 0) {
+		paths = resolveRunPaths(elf, elf->RunPath());
+		if(findLibraryByDirs(elf, lib, paths)) {
+			return true;
+		}
+	} else if(elf->RPath().size() > 0) {
+		paths = resolveRunPaths(elf, elf->RPath());
+		if(findLibraryByDirs(elf, lib, paths)) {
+			return true;
+		}
+	}
+
+	if(findLibraryByDirs(elf, lib, dirs)) {
+		return true;
+	}
+
+	if(pkg.Dirs().size() > 0 && findLibraryByDirs(elf, lib, pkg.Dirs())) {
+		return true;
+	}
+
+	return false;
+}
diff --git a/revdep/global.h b/revdep/elf-cache.h
index bfeaeb9..829d96a 100644
--- a/revdep/global.h
+++ b/revdep/elf-cache.h
@@ -1,4 +1,4 @@
-// Copyright (C) 2015 James Buren
+// Copyright (C) 2016 James Buren
 //
 // This file is part of revdep.
 //
@@ -17,17 +17,20 @@
 
 #pragma once
 
-#include "package.h"
+#include "elf.h"
+#include "pkg.h"
+#include <unordered_map>
 
-typedef struct
-{
-	int verbose;
-} Global_Data;
+typedef std::unordered_map <std::string, Elf *> ElfMap;
 
-#ifdef _IN_GLOBAL_
-extern Global_Data rd;
-#else
-extern const Global_Data rd;
-#endif
+class ElfCache {
+private:
+	ElfMap _data;
+	bool findLibraryByDirs(const Elf *elf, const std::string &lib, const StringVector &dirs);
+	bool findLibraryByPath(const Elf *elf, const std::string &lib);
 
-extern int global_setup(int argc, char **argv, int *arg_start, PackageList *pkgs);
+public:
+	~ElfCache();
+	const Elf *LookUp(const std::string &path);
+	bool FindLibrary(const Elf *elf, const Package &pkg, const std::string &lib, const StringVector &dirs);
+};
diff --git a/revdep/elf.cpp b/revdep/elf.cpp
new file mode 100644
index 0000000..6335714
--- /dev/null
+++ b/revdep/elf.cpp
@@ -0,0 +1,177 @@
+// Copyright (C) 2016 James Buren
+//
+// This file is part of revdep.
+//
+// revdep is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// revdep is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with revdep.  If not, see <http://www.gnu.org/licenses/>.
+
+#include "elf.h"
+#include <stdexcept>
+#include <gelf.h>
+#include <fcntl.h>
+#include <unistd.h>
+
+__attribute__((constructor)) static void initialize() {
+	if(elf_version(EV_CURRENT) == EV_NONE) {
+		throw std::runtime_error("libelf initialization failure");
+	}
+}
+
+static bool isValidElf(Elf *elf, int &machine) {
+	GElf_Ehdr ehdr;
+
+	if(elf_kind(elf) != ELF_K_ELF) {
+		return false;
+	}
+
+	if(gelf_getehdr(elf, &ehdr) == NULL) {
+		return false;
+	}
+
+	switch(ehdr.e_type) {
+		case ET_EXEC: break;
+		case ET_DYN:  break;
+		default:      return false;
+	}
+
+	switch(ehdr.e_ident[EI_OSABI]) {
+		case ELFOSABI_NONE:  break;
+		case ELFOSABI_LINUX: break;
+		default:             return false;
+	}
+
+	switch(ehdr.e_machine) {
+#if   defined(__i386__)
+		case EM_386:    break;
+#elif defined(__x86_64__)
+		case EM_386:    break;
+		case EM_X86_64: break;
+#elif defined(__arm__)
+		case EM_ARM:    break;
+#else
+#error "unsupported architecture"
+#endif
+		default:        return false;
+	}
+
+	machine = ehdr.e_machine;
+
+	return true;
+}
+
+static bool getDynamicSection(Elf *elf, GElf_Shdr &shdr, Elf_Scn *&scn) {
+	size_t phdrnum;
+	size_t i;
+	GElf_Phdr phdr;
+
+	if(elf_getphdrnum(elf, &phdrnum) == -1) {
+		return false;
+	}
+
+	for( i = 0 ; i < phdrnum ; ++i ) {
+		if(gelf_getphdr(elf, i, &phdr) == NULL) {
+			continue;
+		}
+
+		if(phdr.p_type != PT_DYNAMIC) {
+			continue;
+		}
+
+		scn = gelf_offscn(elf, phdr.p_offset);
+
+		if(scn == NULL) {
+			continue;
+		}
+
+		if(gelf_getshdr(scn, &shdr) == NULL) {
+			continue;
+		}
+
+		if(shdr.sh_type == SHT_DYNAMIC) {
+			break;
+		}
+	}
+
+	return (i != phdrnum);
+}
+
+static bool readDynamicSection(Elf *elf, StringVector &needed, StringVector &rpath, StringVector &runpath) {
+	GElf_Shdr shdr;
+	Elf_Scn *scn = NULL;
+	Elf_Data *data;
+	size_t size;
+	GElf_Dyn dyn;
+
+	if(!getDynamicSection(elf, shdr, scn)) {
+		return false;
+	}
+
+	data = elf_getdata(scn, NULL);
+
+	if(data == NULL) {
+		return false;
+	}
+
+	size = shdr.sh_size / gelf_fsize(elf, ELF_T_DYN, 1, EV_CURRENT);
+
+	for( size_t i = 0 ; i < size ; ++i ) {
+		if(gelf_getdyn(data, i, &dyn) == NULL) {
+			break;
+		}
+
+		switch(dyn.d_tag) {
+			case DT_NEEDED:
+				needed.push_back(elf_strptr(elf, shdr.sh_link, dyn.d_un.d_val));
+				break;
+
+			case DT_RPATH:
+				split(elf_strptr(elf, shdr.sh_link, dyn.d_un.d_val), rpath, ':');
+				break;
+
+			case DT_RUNPATH:
+				split(elf_strptr(elf, shdr.sh_link, dyn.d_un.d_val), runpath, ':');
+				break;
+		}
+	}
+
+	return true;
+}
+
+Elf::Elf(const std::string &path) {
+	_initialized = false;
+
+	int fd = open(path.c_str(), O_RDONLY);
+
+	if(fd == -1) {
+		return;
+	}
+
+	Elf *elf = elf_begin(fd, ELF_C_READ_MMAP, NULL);
+
+	if(elf == NULL) {
+		close(fd);
+		return;
+	}
+
+	if(!isValidElf(elf, _machine) || !readDynamicSection(elf, _needed, _rpath, _runpath)) {
+		elf_end(elf);
+		close(fd);
+		return;
+	}
+
+	_path = path;
+	_initialized = true;
+
+	elf_end(elf);
+	close(fd);
+}
diff --git a/revdep/elf.h b/revdep/elf.h
new file mode 100644
index 0000000..f7b1860
--- /dev/null
+++ b/revdep/elf.h
@@ -0,0 +1,42 @@
+// Copyright (C) 2016 James Buren
+//
+// This file is part of revdep.
+//
+// revdep is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// revdep is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with revdep.  If not, see <http://www.gnu.org/licenses/>.
+
+#pragma once
+
+#include "utility.h"
+
+class Elf {
+private:
+	int _machine;
+	StringVector _needed;
+	StringVector _rpath;
+	StringVector _runpath;
+	std::string _path;
+	bool _initialized;
+
+public:
+	Elf(const std::string &path);
+
+	      int           Machine() const { return _machine;     }
+	const StringVector& Needed()  const { return _needed;      }
+	const StringVector& RPath()   const { return _rpath;       }
+	const StringVector& RunPath() const { return _runpath;     }
+	const std::string&  Path()    const { return _path;        }
+	      bool          Valid()   const { return _initialized; }
+
+	bool Compatible(const Elf &elf) const { return _machine == elf._machine; }
+};
diff --git a/revdep/global.c b/revdep/global.c
deleted file mode 100644
index 4730d3d..0000000
--- a/revdep/global.c
+++ /dev/null
@@ -1,116 +0,0 @@
-// Copyright (C) 2015 James Buren
-//
-// This file is part of revdep.
-//
-// revdep is free software: you can redistribute it and/or modify
-// it under the terms of the GNU General Public License as published by
-// the Free Software Foundation, either version 3 of the License, or
-// (at your option) any later version.
-//
-// revdep is distributed in the hope that it will be useful,
-// but WITHOUT ANY WARRANTY; without even the implied warranty of
-// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-// GNU General Public License for more details.
-//
-// You should have received a copy of the GNU General Public License
-// along with revdep.  If not, see <http://www.gnu.org/licenses/>.
-
-#define _IN_GLOBAL_
-#include "global.h"
-#include "utility.h"
-#include <stdlib.h>
-#include <stdio.h>
-#include <string.h>
-#include <unistd.h>
-#include <errno.h>
-#include <gelf.h>
-
-Global_Data rd =
-{
-	.verbose = 0
-};
-
-static void ignore_packages(char *list, PackageList *pkgs)
-{
-	char *s;
-	char *e;
-	Package *pkg;
-
-	for( s = list ; (e = strchr(s, ',')) != NULL ; s = e + 1 )
-	{
-		e[0] = '\0';
-
-		if((pkg = packages_search(pkgs, s)) != NULL)
-		{
-			pkg->ignore = 1;
-		}
-
-		e[0] = ',';
-	}
-
-	if((pkg = packages_search(pkgs, s)) != NULL)
-	{
-		pkg->ignore = 1;
-	}
-}
-
-extern int global_setup(int argc, char **argv, int *arg_start, PackageList *pkgs)
-{
-	static const char options[] = ":vi:h";
-	int opt;
-
-	if(argc < 1 || argv == NULL || arg_start == NULL)
-	{
-		errno = EINVAL;
-		return -1;
-	}
-
-	if(elf_version(EV_CURRENT) == EV_NONE)
-	{
-		logger(LOG_BRIEF, "libelf: could not initialize version\n");
-		return -1;
-	}
-
-	while((opt = getopt(argc, argv, options)) != -1)
-	{
-		switch(opt)
-		{
-			case 'v':
-				++rd.verbose;
-				break;
-
-			case 'i':
-				ignore_packages(optarg, pkgs);
-				break;
-
-			case 'h':
-				logger(LOG_BRIEF,
-					"%s version %s\n"
-					"Usage: %s [-h] [-v|-vv|-vvv|-vvvv] [package...]\n"
-					"Where commands are:\n"
-					"\t-h    The option -h displays help.\n"
-					"\t-i    Comma-separated list of ports to ignore.\n"
-					"\t-v    Formatted listing.\n"
-					"\t-vv   Include erroneous files.\n"
-					"\t-vvv  Include precise file errors.\n"
-					"\t-vvvv Show debug/trace.\n",
-					argv[0],
-					VERSION,
-					argv[0]
-				);
-				return -1;
-
-			case '?':
-				logger(LOG_BRIEF, "%c: unknown option\n", optopt);
-				return -1;
-
-			case ':':
-				logger(LOG_BRIEF, "%c: missing argument\n", optopt);
-				return -1;
-		}
-	}
-
-	arg_start[0] = optind;
-
-	return 0;
-}
diff --git a/revdep/main.c b/revdep/main.c
deleted file mode 100644
index 5678b0c..0000000
--- a/revdep/main.c
+++ /dev/null
@@ -1,293 +0,0 @@
-// Copyright (C) 2015 James Buren
-//
-// This file is part of revdep.
-//
-// revdep is free software: you can redistribute it and/or modify
-// it under the terms of the GNU General Public License as published by
-// the Free Software Foundation, either version 3 of the License, or
-// (at your option) any later version.
-//
-// revdep is distributed in the hope that it will be useful,
-// but WITHOUT ANY WARRANTY; without even the implied warranty of
-// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-// GNU General Public License for more details.
-//
-// You should have received a copy of the GNU General Public License
-// along with revdep.  If not, see <http://www.gnu.org/licenses/>.
-
-#define _IN_MAIN_
-#include "main.h"
-#include "global.h"
-#include "package.h"
-#include "utility.h"
-#include <stdlib.h>
-#include <stdio.h>
-#include <string.h>
-#include <libgen.h>
-
-static int run_ld_on_file(Package *pkg, File *file)
-{
-	const char *ld;
-	char command[4096];
-	FILE *in;
-	char line[4096];
-	char libs[4096];
-	char *s;
-	char *e;
-	File *file2;
-	char dir[4096];
-	char dirs[4096];
-
-	inline int run_ld(void)
-	{
-		if((in = popen(command, "r")) == NULL)
-		{
-			logger(LOG_ERROR, "%s:%s: could not execute LD\n", pkg->name, file->path);
-			return -1;
-		}
-
-		libs[0] = '\0';
-
-		while(fgets(line, sizeof(line), in) != NULL)
-		{
-			if(strstr(line, "not found") != NULL)
-			{
-				if((s = strstr(line, "=>")) != NULL)
-				{
-					s[0] = '\0';
-				}
-
-				snprintf(libs + strlen(libs), sizeof(libs) - strlen(libs), "%s%s",
-					(libs[0] == '\0') ? "" : ":", strtrim(line));
-			}
-		}
-
-		pclose(in);
-
-		if(libs[0] == '\0')
-		{
-			return 0;
-		}
-
-		return 1;
-	}
-
-	logger(LOG_DEBUG, "%s:%s: checking file\n", pkg->name, file->path);
-
-	if(get_ld_for_file(pkg->name, file->path, &ld) == -1)
-	{
-		return 0;
-	}
-
-	logger(LOG_DEBUG, "%s:%s: is ELF\n", pkg->name, file->path);
-
-	snprintf(command, sizeof(command), "LD_TRACE_LOADED_OBJECTS=1 '%s' '%s'", ld, file->path);
-
-	switch(run_ld())
-	{
-		case  0:
-			return  0;
-		case -1:
-			return -1;
-		case  1:
-			break;
-	}
-
-	for( s = libs, dirs[0] = '\0' ; (e = strchr(s, ':')) != NULL ; s = e + 1 )
-	{
-		e[0] = '\0';
-
-		if((file2 = files_search(pkg->files, s, FILE_COMPARE_WITHIN)) != NULL)
-		{
-			snprintf(dir, sizeof(dir), "%s", file2->path);
-			snprintf(dirs + strlen(dirs), sizeof(dirs) - strlen(dirs), "%s%s",
-				(dirs[0] == '\0') ? "" : ":", dirname(dir));
-		}
-		else
-		{
-			logger(LOG_ERROR, "%s:%s: missing library\n", pkg->name, file->path);
-			return -1;
-		}
-
-		e[0] = ':';
-	}
-
-	if((file2 = files_search(pkg->files, s, FILE_COMPARE_WITHIN)) != NULL)
-	{
-		snprintf(dir, sizeof(dir), "%s", file2->path);
-		snprintf(dirs + strlen(dirs), sizeof(dirs) - strlen(dirs), "%s%s",
-			(dirs[0] == '\0') ? "" : ":", dirname(dir));
-	}
-	else
-	{
-		logger(LOG_ERROR, "%s:%s: missing library\n", pkg->name, file->path);
-		return -1;
-	}
-
-	snprintf(command, sizeof(command), "LD_TRACE_LOADED_OBJECTS=1 LD_LIBRARY_PATH=\"$LD_LIBRARY_PATH:%s\" '%s' '%s'", dirs, ld, file->path);
-
-	switch(run_ld())
-	{
-		case  0:
-			return  0;
-		case -1:
-			return -1;
-		case  1:
-			break;
-	}
-
-	logger(LOG_ERROR, "%s:%s: missing library\n", pkg->name, file->path);
-
-	return -1;
-}
-
-static int work_package(Package *pkg)
-{
-	unsigned int i;
-	FileList *files;
-	File *file;
-	int rv;
-
-	if(pkg->ignore)
-	{
-		return 0;
-	}
-
-	for( i = rv = 0, files = pkg->files ; i < files->length ; ++i )
-	{
-		file = &files->list[i];
-
-		if(run_ld_on_file(pkg, file) == -1)
-		{
-			logger(LOG_INFO_2, "%s:%s: error\n", pkg->name, file->path);
-
-			rv = -1;
-		}
-	}
-
-	return rv;
-}
-
-static void work_all_packages(PackageList *pkgs)
-{
-	unsigned int i;
-	Package *pkg;
-
-	logger(LOG_INFO_1,
-		"** checking %u ports\n"
-		"** check linking\n",
-		pkgs->length
-	);
-
-	for( i = 0 ; i < pkgs->length ; ++i )
-	{
-		pkg = &pkgs->list[i];
-
-		if(work_package(pkg) == -1)
-		{
-			const char *fmt;
-			int level;
-
-			if(rd.verbose == 0)
-			{
-				fmt = "%s\n";
-				level = LOG_BRIEF;
-			}
-			else
-			{
-				fmt = "%s: error\n";
-				level = LOG_INFO_1;
-			}
-
-			logger(level, fmt, pkg->name);
-		}
-		else
-		{
-			logger(LOG_INFO_1, "%s: ok\n", pkg->name);
-		}
-	}
-}
-
-static void work_specific_packages(PackageList *pkgs, int i, int argc, char **argv)
-{
-	char *name;
-	Package *pkg;
-
-	logger(LOG_INFO_1,
-		"** checking %d ports\n"
-		"** check linking\n",
-		argc - i
-	);
-
-	for( ; i < argc ; ++i )
-	{
-		name = argv[i];
-
-		if((pkg = packages_search(pkgs, name)) == NULL)
-		{
-			logger(LOG_INFO_1, "%s: cannot find package information\n", name);
-			continue;
-		}
-
-		if(work_package(pkg) == -1)
-		{
-			const char *fmt;
-			int level;
-
-			if(rd.verbose == 0)
-			{
-				fmt = "%s\n";
-				level = LOG_BRIEF;
-			}
-			else
-			{
-				fmt = "%s: error\n";
-				level = LOG_INFO_1;
-			}
-
-			logger(level, fmt, pkg->name);
-		}
-		else
-		{
-			logger(LOG_INFO_1, "%s: ok\n", pkg->name);
-		}
-	}
-}
-
-extern int main(int argc, char **argv)
-{
-	static const char DB[] = "/var/lib/pkg/db";
-	int start;
-	PackageList *pkgs;
-
-	pkgs = packages_load_from_database(DB);
-
-	if(pkgs == NULL)
-	{
-		logger(LOG_BRIEF, "%s: could not open the database\n", DB);
-		return EXIT_FAILURE;
-	}
-
-	packages_sort(pkgs);
-	packages_sort_all_files(pkgs);
-
-	if(global_setup(argc, argv, &start, pkgs) == -1)
-	{
-		return EXIT_FAILURE;
-	}
-
-	logger(LOG_INFO_1, "** calculating deps\n");
-
-	if(start == argc)
-	{
-		work_all_packages(pkgs);
-	}
-	else
-	{
-		work_specific_packages(pkgs, start, argc, argv);
-	}
-
-	packages_free(pkgs);
-
-	return EXIT_SUCCESS;
-}
diff --git a/revdep/main.cpp b/revdep/main.cpp
new file mode 100644
index 0000000..0b000b5
--- /dev/null
+++ b/revdep/main.cpp
@@ -0,0 +1,260 @@
+// Copyright (C) 2016 James Buren
+//
+// This file is part of revdep.
+//
+// revdep is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// revdep is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with revdep.  If not, see <http://www.gnu.org/licenses/>.
+
+#include "main.h"
+#include "pkg.h"
+#include "elf-cache.h"
+#include <algorithm>
+#include <unistd.h>
+#include <stdarg.h>
+
+enum {
+	BRIEF,
+	INFO1,
+	INFO2,
+	ERROR,
+	DEBUG
+};
+
+static std::string PKG_DB_PATH = "/var/lib/pkg/db";
+static std::string LD_CONF_PATH = "/etc/ld.so.conf";
+static std::string RD_CONF_PATH = "/etc/revdep.d";
+static StringVector ignores;
+static int level = BRIEF;
+static PackageVector pkgs;
+static StringVector dirs;
+static ElfCache ec;
+
+static void logger(int lvl, const char *fmt, ...) __attribute__((format(printf,2,3)));
+
+static void logger(int lvl, const char *fmt, ...) {
+	if(lvl > level) {
+		return;
+	}
+
+	va_list args;
+
+	va_start(args, fmt);
+
+	vfprintf(stdout, fmt, args);
+
+	va_end(args);
+}
+
+static bool parseArgs(int argc, char **argv) {
+	static const char OPTIONS[] = ":hd:c:r:i:v";
+	int opt;
+
+	while((opt = getopt(argc, argv, OPTIONS)) != -1) {
+		switch(opt) {
+			case 'h':
+				logger(BRIEF, "%s version %s\n", argv[0], VERSION);
+				logger(BRIEF, "Usage: %s [-h] [-v|-vv|-vvv|-vvvv] [package...]\n", argv[0]);
+				logger(BRIEF, "Where commands are:\n");
+				logger(BRIEF, "\t-h    The option -h displays help\n");
+				logger(BRIEF, "\t-d    Specify an alternate location for the package database\n");
+				logger(BRIEF, "\t-c    Specify an alternate location for ld.so.conf\n");
+				logger(BRIEF, "\t-r    Specify an alternate directory for revdep package config\n");
+				logger(BRIEF, "\t-i    Comma-separated list of ports to ignore\n");
+				logger(BRIEF, "\t-v    Formatted listing\n");
+				logger(BRIEF, "\t-vv   Include erroneous files\n");
+				logger(BRIEF, "\t-vvv  Include precise file errors\n");
+				logger(BRIEF, "\t-vvvv Show debug/trace\n");
+				return false;
+
+			case 'd':
+				PKG_DB_PATH = optarg;
+				break;
+
+			case 'c':
+				LD_CONF_PATH = optarg;
+				break;
+
+			case 'i':
+				split(optarg, ignores, ',');
+				break;
+
+			case 'r':
+				RD_CONF_PATH = optarg;
+				break;
+
+			case 'v':
+				++level;
+				break;
+
+			case ':':
+				logger(BRIEF, "%c: missing argument\n", optopt);
+				return false;
+
+			case '?':
+				logger(BRIEF, "%c: invalid option\n", optopt);
+				return false;
+		}
+	}
+
+	return true;
+}
+
+static void ignorePackages(PackageVector &pkgs, const StringVector &ignores) {
+	for( size_t i = 0 ; i < ignores.size() ; ++i ) {
+		PackageVector::iterator pkg = std::find(pkgs.begin(), pkgs.end(), ignores[i]);
+
+		if(pkg == pkgs.end()) {
+			continue;
+		}
+
+		pkg->Ignore();
+	}
+}
+
+static bool workFile(const Package &pkg, const std::string &file) {
+	bool rv = true;
+
+	logger(DEBUG, "%s:%s: checking file\n", pkg.Name().c_str(), file.c_str());
+
+	if(!IsFile(file)) {
+		return rv;
+	}
+
+	const Elf *elf = ec.LookUp(file);
+
+	if(elf == NULL) {
+		return rv;
+	}
+
+	logger(DEBUG, "%s:%s: is ELF\n", pkg.Name().c_str(), file.c_str());
+
+	for( size_t i = 0 ; i < elf->Needed().size() ; ++i ) {
+		const std::string &lib = elf->Needed()[i];
+
+		if(!ec.FindLibrary(elf, pkg, lib, dirs)) {
+			logger(ERROR, "%s:%s:%s: missing library\n", pkg.Name().c_str(), file.c_str(), lib.c_str());
+			rv = false;
+		}
+	}
+
+	return rv;
+}
+
+static bool workPackage(const Package &pkg) {
+	bool rv = true;
+
+	if(pkg.Ignore()) {
+		return rv;
+	}
+
+	for( size_t i = 0 ; i < pkg.Files().size() ; ++i ) {
+		const std::string &file = pkg.Files()[i];
+
+		if(!workFile(pkg, file)) {
+			logger(INFO2, "%s:%s: error\n", pkg.Name().c_str(), file.c_str());
+			rv = false;
+		}
+	}
+
+	return rv;
+}
+
+static void workAllPackages(const PackageVector &pkgs) {
+	logger(INFO1, "** checking %zu ports\n", pkgs.size());
+	logger(INFO1, "** checking linking\n");
+
+	for( size_t i = 0 ; i < pkgs.size() ; ++i ) {
+		const Package &pkg = pkgs[i];
+
+		if(!workPackage(pkg)) {
+			int lvl;
+			const char *fmt;
+
+			if(level > BRIEF) {
+				lvl = INFO1;
+				fmt = "%s: error\n";
+			} else {
+				lvl = BRIEF;
+				fmt = "%s\n";
+			}
+
+			logger(lvl, fmt, pkg.Name().c_str());
+		} else {
+			logger(INFO1, "%s: ok\n", pkg.Name().c_str());
+		}
+	}
+}
+
+static void workSpecificPackages(const PackageVector &pkgs, int i, int argc, char **argv) {
+	logger(INFO1, "** checking %d ports\n", argc - i);
+	logger(INFO1, "** checking linking\n");
+
+	for( ; i < argc ; ++i ) {
+		const std::string name = argv[i];
+		PackageVector::const_iterator pkg = std::find(pkgs.begin(), pkgs.end(), name);
+
+		if(pkg == pkgs.end()) {
+			logger(INFO1, "%s: cannot find package information\n", name.c_str());
+			continue;
+		}
+
+		if(!workPackage(pkg[0])) {
+			int lvl;
+			const char *fmt;
+
+			if(level > BRIEF) {
+				lvl = INFO1;
+				fmt = "%s: error\n";
+			} else {
+				lvl = BRIEF;
+				fmt = "%s\n";
+			}
+
+			logger(lvl, fmt, pkg->Name().c_str());
+		} else {
+			logger(INFO1, "%s: ok\n", pkg->Name().c_str());
+		}
+	}
+}
+
+int main(int argc, char **argv) {
+	if(!parseArgs(argc, argv)) {
+		return 1;
+	}
+
+	if(!ReadPackages(PKG_DB_PATH, pkgs)) {
+		logger(BRIEF, "%s:%s: failed to read package database\n", argv[0], PKG_DB_PATH.c_str());
+		return 1;
+	}
+
+	if(!ReadLdConf(LD_CONF_PATH, dirs, 10)) {
+		logger(BRIEF, "%s:%s: failed to read ld conf\n", argv[0], LD_CONF_PATH.c_str());
+		return 1;
+	}
+
+	dirs.push_back("/lib");
+	dirs.push_back("/usr/lib");
+
+	ReadPackageDirs(RD_CONF_PATH, pkgs);
+	ignorePackages(pkgs, ignores);
+
+	logger(INFO1, "** calculating deps\n");
+
+	if(optind == argc) {
+		workAllPackages(pkgs);
+	} else {
+		workSpecificPackages(pkgs, optind, argc, argv);
+	}
+
+	return 0;
+}
diff --git a/revdep/main.h b/revdep/main.h
index 6c4aabf..fa5b964 100644
--- a/revdep/main.h
+++ b/revdep/main.h
@@ -1,4 +1,4 @@
-// Copyright (C) 2015 James Buren
+// Copyright (C) 2016 James Buren
 //
 // This file is part of revdep.
 //
@@ -17,4 +17,4 @@
 
 #pragma once
 
-extern int main(int argc, char **argv);
+int main(int argc, char **argv);
diff --git a/revdep/package.c b/revdep/package.c
deleted file mode 100644
index 4acb723..0000000
--- a/revdep/package.c
+++ /dev/null
@@ -1,303 +0,0 @@
-// Copyright (C) 2015 James Buren
-//
-// This file is part of revdep.
-//
-// revdep is free software: you can redistribute it and/or modify
-// it under the terms of the GNU General Public License as published by
-// the Free Software Foundation, either version 3 of the License, or
-// (at your option) any later version.
-//
-// revdep is distributed in the hope that it will be useful,
-// but WITHOUT ANY WARRANTY; without even the implied warranty of
-// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-// GNU General Public License for more details.
-//
-// You should have received a copy of the GNU General Public License
-// along with revdep.  If not, see <http://www.gnu.org/licenses/>.
-
-#define _IN_PACKAGE_
-#include "package.h"
-#include "utility.h"
-#include <stdlib.h>
-#include <stdio.h>
-#include <string.h>
-#include <errno.h>
-#include <search.h>
-
-extern PackageList *packages_load_from_database(const char *path)
-{
-	char *text;
-	unsigned int length;
-	char name[1024];
-	char version[1024];
-	char pathname[1024];
-	PackageList *pkgs;
-	Package *pkg;
-	FileList *files;
-	File *file;
-
-	if(path == NULL || path[0] == '\0')
-	{
-		errno = EINVAL;
-		return NULL;
-	}
-
-	void parse_callback(int record, int field, char *start, char *end)
-	{
-		if(field == 0)
-		{
-			snprintf(name, sizeof(name), "%.*s", (int) (end - start), start);
-		}
-		else if(field == 1)
-		{
-			snprintf(version, sizeof(version), "%.*s", (int) (end - start), start);
-		}
-		else if(field == 2)
-		{
-			snprintf(pathname, sizeof(pathname), "/%.*s", (int) (end - start), start);
-
-			files = new(FileList, 1);
-			files->length = 0;
-			files->size = 256;
-			files->list = new(File, files->size);
-
-			file = &files->list[files->length];
-			file->path = xstrdup(pathname);
-			file->key = string_crc32(pathname);
-			++files->length;
-
-			if(pkgs->length == pkgs->size)
-			{
-				pkgs->size *= 2;
-				pkgs->list = renew(pkgs->list, Package, pkgs->size);
-			}
-
-			pkg = &pkgs->list[pkgs->length];
-			pkg->name = xstrdup(name);
-			pkg->version = xstrdup(version);
-			pkg->files = files;
-			pkg->key = string_crc32(name);
-			pkg->ignore = 0;
-			++pkgs->length;
-		}
-		else
-		{
-			snprintf(pathname, sizeof(pathname), "/%.*s", (int) (end - start), start);
-
-			if(files->length == files->size)
-			{
-				files->size *= 2;
-				files->list = renew(files->list, File, files->size);
-			}
-
-			file = &files->list[files->length];
-			file->path = xstrdup(pathname);
-			file->key = string_crc32(pathname);
-			++files->length;
-		}
-	}
-
-	if(open_file_in_memory(path, &text, &length) == -1)
-	{
-		return NULL;
-	}
-
-	pkgs = new(PackageList, 1);
-	pkgs->length = 0;
-	pkgs->size = 256;
-	pkgs->list = new(Package, pkgs->size);
-
-	if(parse_file_in_memory(text, parse_callback) == -1)
-	{
-		packages_free(pkgs);
-		close_file_in_memory(text, length);
-		return NULL;
-	}
-
-	if(pkgs->length == 0)
-	{
-		packages_free(pkgs);
-		close_file_in_memory(text, length);
-		return NULL;
-	}
-
-	close_file_in_memory(text, length);
-
-	return pkgs;
-}
-
-extern void packages_free(PackageList *pkgs)
-{
-	unsigned int i;
-	Package *pkg;
-
-	if(pkgs == NULL)
-		return;
-
-	for( i = 0 ; i < pkgs->length ; ++i )
-	{
-		pkg = &pkgs->list[i];
-		free(pkg->name);
-		free(pkg->version);
-		files_free(pkg->files);
-	}
-
-	free(pkgs->list);
-
-	free(pkgs);
-}
-
-extern void packages_sort(PackageList *pkgs)
-{
-	if(pkgs == NULL)
-		return;
-
-	int package_compare(const void *A, const void *B)
-	{
-		const Package *a = A;
-		const Package *b = B;
-
-		if(a->key < b->key)
-			return -1;
-
-		if(a->key > b->key)
-			return 1;
-
-		return 0;
-	}
-
-	qsort(pkgs->list, pkgs->length, sizeof(Package), package_compare);
-}
-
-extern void packages_sort_all_files(PackageList *pkgs)
-{
-	unsigned int i;
-	FileList *files;
-
-	if(pkgs == NULL)
-		return;
-
-	for( i = 0 ; i < pkgs->length ; ++i )
-	{
-		files = pkgs->list[i].files;
-		files_sort(files);
-	}
-}
-
-extern Package *packages_search(PackageList *pkgs, const char *name)
-{
-	unsigned int key;
-
-	if(pkgs == NULL || name == NULL || name[0] == '\0')
-	{
-		errno = EINVAL;
-		return NULL;
-	}
-
-	int package_compare(const void *A, const void *B)
-	{
-		const unsigned int *a = A;
-		const Package *b = B;
-
-		if(a[0] < b->key)
-			return -1;
-
-		if(a[0] > b->key)
-			return 1;
-
-		return 0;
-	}
-
-	key = string_crc32(name);
-
-	return bsearch(&key, pkgs->list, pkgs->length, sizeof(Package), package_compare);
-}
-
-extern void files_sort(FileList *files)
-{
-	if(files == NULL)
-		return;
-
-	int file_compare(const void *A, const void *B)
-	{
-		const File *a = A;
-		const File *b = B;
-
-		if(a->key < b->key)
-			return -1;
-
-		if(a->key > b->key)
-			return 1;
-
-		return 0;
-	}
-
-	qsort(files->list, files->length, sizeof(File), file_compare);
-}
-
-extern void files_free(FileList *files)
-{
-	unsigned int i;
-	File *file;
-
-	if(files == NULL)
-		return;
-
-	for( i = 0 ; i < files->length ; ++i )
-	{
-		file = &files->list[i];
-		free(file->path);
-	}
-
-	free(files->list);
-
-	free(files);
-}
-
-extern File *files_search(FileList *files, const char *key, int compare_type)
-{
-	unsigned int hash;
-	size_t n;
-
-	if(files == NULL || key == NULL || key[0] == '\0')
-	{
-		errno = EINVAL;
-		return NULL;
-	}
-
-	int file_compare_exact(const void *A, const void *B)
-	{
-		const unsigned int *a = A;
-		const File *b = B;
-
-		if(a[0] < b->key)
-			return -1;
-
-		if(a[0] > b->key)
-			return 1;
-
-		return 0;
-	}
-
-	int file_compare_within(const void *A, const void *B)
-	{
-		const char *a = A;
-		const File *b = B;
-
-		return (strstr(b->path, a) == NULL);
-	}
-
-	switch(compare_type)
-	{
-		case FILE_COMPARE_EXACT:
-			hash = string_crc32(key);
-			return bsearch(&hash, files->list, files->length, sizeof(File), file_compare_exact);
-
-		case FILE_COMPARE_WITHIN:
-			n = files->length;
-			return lfind(key, files->list, &n, sizeof(File), file_compare_within);
-
-		default:
-			return NULL;
-	}
-}
diff --git a/revdep/package.h b/revdep/package.h
deleted file mode 100644
index 1254fb3..0000000
--- a/revdep/package.h
+++ /dev/null
@@ -1,62 +0,0 @@
-// Copyright (C) 2015 James Buren
-//
-// This file is part of revdep.
-//
-// revdep is free software: you can redistribute it and/or modify
-// it under the terms of the GNU General Public License as published by
-// the Free Software Foundation, either version 3 of the License, or
-// (at your option) any later version.
-//
-// revdep is distributed in the hope that it will be useful,
-// but WITHOUT ANY WARRANTY; without even the implied warranty of
-// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-// GNU General Public License for more details.
-//
-// You should have received a copy of the GNU General Public License
-// along with revdep.  If not, see <http://www.gnu.org/licenses/>.
-
-#pragma once
-
-typedef struct
-{
-	char *path;
-	unsigned int key;
-} File;
-
-typedef struct
-{
-	File *list;
-	unsigned int length;
-	unsigned int size;
-} FileList;
-
-typedef struct
-{
-	char *name;
-	char *version;
-	FileList *files;
-	unsigned int key;
-	unsigned int ignore;
-} Package;
-
-typedef struct
-{
-	Package *list;
-	unsigned int length;
-	unsigned int size;
-} PackageList;
-
-enum
-{
-	FILE_COMPARE_EXACT,
-	FILE_COMPARE_WITHIN
-};
-
-extern PackageList *packages_load_from_database(const char *path);
-extern void packages_free(PackageList *pkgs);
-extern void packages_sort(PackageList *pkgs);
-extern void packages_sort_all_files(PackageList *pkgs);
-extern Package *packages_search(PackageList *pkgs, const char *name);
-extern void files_sort(FileList *files);
-extern void files_free(FileList *files);
-extern File *files_search(FileList *files, const char *key, int compare_type);
diff --git a/revdep/pkg.cpp b/revdep/pkg.cpp
new file mode 100644
index 0000000..f79a872
--- /dev/null
+++ b/revdep/pkg.cpp
@@ -0,0 +1,111 @@
+// Copyright (C) 2016 James Buren
+//
+// This file is part of revdep.
+//
+// revdep is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// revdep is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with revdep.  If not, see <http://www.gnu.org/licenses/>.
+
+#include "pkg.h"
+#include <fstream>
+#include <algorithm>
+#include <dirent.h>
+
+Package::Package(const std::string &name, const std::string &version, const StringVector &files) {
+	_name = name;
+	_version = version;
+	_files = files;
+	_dirs = {};
+	_ignore = false;
+}
+
+static Package readPackage(std::istream &in) {
+	std::string line;
+	size_t fields = 0;
+	std::string name;
+	std::string version;
+	StringVector files;
+
+	while(getline(in, line) && line != "") {
+		switch(++fields) {
+			case 1:                  name = line; break;
+			case 2:               version = line; break;
+			default: files.push_back("/" + line); break;
+		}
+	}
+
+	if(fields < 2) {
+		return Package("", "", files);
+	}
+
+	return Package(name, version, files);
+}
+
+bool ReadPackages(const std::string &path, PackageVector &pkgs) {
+	std::ifstream fin;
+
+	fin.open(path.c_str());
+
+	if(!fin.is_open()) {
+		return false;
+	}
+
+	while(true) {
+		Package pkg = readPackage(fin);
+
+		if(pkg.Name() == "" && pkg.Version() == "") {
+			break;
+		}
+
+		pkgs.push_back(pkg);
+	}
+
+	fin.close();
+
+	return (pkgs.size() > 0);
+}
+
+void ReadPackageDirs(const std::string &path, PackageVector &pkgs) {
+	DIR *dir;
+
+	dir = opendir(path.c_str());
+
+	if(dir == NULL) {
+		return;
+	}
+
+	struct dirent de, *res;
+
+	while(readdir_r(dir, &de, &res) == 0 && res != NULL) {
+		if(de.d_type != DT_REG) {
+			continue;
+		}
+
+		StringVector dirs;
+
+		ReadRdConf(path + "/" + de.d_name, dirs);
+
+		if(dirs.size() == 0) {
+			continue;
+		}
+
+		PackageVector::iterator pkg = std::find(pkgs.begin(), pkgs.end(), de.d_name);
+
+		if(pkg == pkgs.end()) {
+			continue;
+		}
+
+		pkg->Dirs(dirs);
+	}
+
+	closedir(dir);
+}
diff --git a/revdep/pkg.h b/revdep/pkg.h
new file mode 100644
index 0000000..d3e299b
--- /dev/null
+++ b/revdep/pkg.h
@@ -0,0 +1,47 @@
+// Copyright (C) 2016 James Buren
+//
+// This file is part of revdep.
+//
+// revdep is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// revdep is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with revdep.  If not, see <http://www.gnu.org/licenses/>.
+
+#pragma once
+
+#include "utility.h"
+
+class Package {
+private:
+	std::string _name;
+	std::string _version;
+	StringVector _files;
+	StringVector _dirs;
+	bool _ignore;
+
+public:
+	Package(const std::string &name, const std::string &version, const StringVector &files);
+
+	const std::string&  Name()                         const { return _name;    }
+	const std::string&  Version()                      const { return _version; }
+	const StringVector& Files()                        const { return _files;   }
+	const StringVector& Dirs()                         const { return _dirs;    }
+	      void          Dirs(const StringVector &dirs)       { _dirs = dirs;    }
+	      bool          Ignore()                       const { return _ignore;  }
+	      void          Ignore()                             { _ignore = true;  }
+
+	bool operator == (const std::string &name) const { return _name == name; }
+};
+
+typedef std::vector <Package> PackageVector;
+
+bool ReadPackages(const std::string &path, PackageVector &pkgs);
+void ReadPackageDirs(const std::string &path, PackageVector &pkgs);
diff --git a/revdep/revdep.1 b/revdep/revdep.1
index 2719435..27e1d62 100644
--- a/revdep/revdep.1
+++ b/revdep/revdep.1
@@ -1,38 +1,52 @@
-." Text automatically generated by txt2man
-.TH revdep  "March 11, 2015" "" ""
+.\"Text automatically generated by txt2man
+.TH untitled  "23 February 2016" "" ""
 .SH NAME
-\fBrevdep \fP- checks for missing / wrong libraries of installed packages using ldd
+\fBrevdep \fP- checks for missing libraries of installed packages
 .SH SYNOPSIS
 .nf
 .fam C
 \fBrevdep\fP [\fB-h\fP] [\fB-v\fP|\fB-vv\fP|\fB-vvv\fP|\fB-vvvv\fP] [package\.\.\.]
 .fam T
 .fi
+.fam T
+.fi
 .SH DESCRIPTION
-Revdep checks for missing / wrong libraries of installed packages using
-\fBldd\fP(1).
+\fBrevdep\fP checks for missing libraries of installed packages using elfutils'
+libelf and the same algorithm that \fBld.so\fP(8) uses.
 .SH OPTIONS
 .TP
 .B
 \fB-h\fP
-The option \fB-h\fP displays help.
+The option \fB-h\fP displays help
+.TP
+.B
+\fB-d\fP
+Specify an alternate location for the package database
+.TP
+.B
+\fB-c\fP
+Specify an alternate location for ld.so.conf
+.TP
+.B
+\fB-r\fP
+Specify an alternate directory for \fBrevdep\fP package config
 .TP
 .B
 \fB-i\fP
-Comma-separated list of ports to ignore.
+Comma-separated list of ports to ignore
 .TP
 .B
 \fB-v\fP
-Formatted listing.
+Formatted listing
 .TP
 .B
 \fB-vv\fP
-Include errorous files.
+Include errorous files
 .TP
 .B
 \fB-vvv\fP
-Include precise file errors.
-\fB-vvvv\fP Show debug/trace.
+Include precise file errors
+\fB-vvvv\fP Show debug/trace
 .SH EXAMPLE
 Try this command to list broken packages:
 .PP
@@ -41,10 +55,27 @@ $ \fBrevdep\fP
 Use this command to rebuild packages on your system:
 .PP
 # prt-get update \fB-fr\fP $(\fBrevdep\fP)
+.SH ADDITIONAL LIBRARY DIRECTORIES
+Upon startup, \fBrevdep\fP searches the /etc/revdep.d directory for files named
+after ports. If any are found, any directories (assumed to be absolute
+pathes and delimited by newlines) within the file are added to a list of
+port specific directories to search if a library dependency is not found
+in one of the many standard locations (as specified by \fBld.so\fP(8)).
+.PP
+If a port is discovered to have library dependencies that are in a
+non-standard location, then a file, as specified above, should be created.
+.PP
+For example, if the port "firefox" has a "libxul.so" dependency in a
+the non-standard directory "/usr/lib/firefox" then a file named "firefox"
+should be created under "/etc/revdep.d" with a single line containing
+"/usr/lib/firefox". This will tell \fBrevdep\fP where to find firefox's "libxul.so"
+when looking for its library dependencies, reducing one source of false
+positives. Ideally, this file would be included with the port's own packaging
+as well.
 .SH NOTES
-C rewrite inspired by Johannes Winkelmann's <jw@tks6.net> shell \fBrevdep\fP.
+C++ rewrite inspired by Johannes Winkelmann's <jw@tks6.net> shell \fBrevdep\fP.
 Contributed to design Danny Rawlins <contact@romster.me>.
 .SH SEE ALSO
-\fBldd\fP(1), \fBprt-get\fP(8), \fBpkginfo\fP(8)
+\fBld.so\fP(8), \fBprt-get\fP(8), \fBpkginfo\fP(1)
 .SH AUTHOR
 James Buren, ryuo @ freenode 
diff --git a/revdep/revdep.man b/revdep/revdep.man
index 744277c..63c26c0 100644
--- a/revdep/revdep.man
+++ b/revdep/revdep.man
@@ -1,17 +1,20 @@
 NAME
-revdep - checks for missing / wrong libraries of installed packages using ldd
+revdep - checks for missing libraries of installed packages
 SYNOPSIS
 revdep [-h] [-v|-vv|-vvv|-vvvv] [package...]
 DESCRIPTION
-Revdep checks for missing / wrong libraries of installed packages using
-ldd(1).
+revdep checks for missing libraries of installed packages using elfutils'
+libelf and the same algorithm that ld.so(8) uses.
 OPTIONS
--h    The option -h displays help.
--i    Comma-separated list of ports to ignore.
--v    Formatted listing.
--vv   Include errorous files.
--vvv  Include precise file errors.
--vvvv Show debug/trace.
+-h    The option -h displays help
+-d    Specify an alternate location for the package database
+-c    Specify an alternate location for ld.so.conf
+-r    Specify an alternate directory for revdep package config
+-i    Comma-separated list of ports to ignore
+-v    Formatted listing
+-vv   Include errorous files
+-vvv  Include precise file errors
+-vvvv Show debug/trace
 EXAMPLE
 Try this command to list broken packages:
  
@@ -20,10 +23,27 @@ $ revdep
 Use this command to rebuild packages on your system:
  
 # prt-get update -fr $(revdep)
+ADDITIONAL LIBRARY DIRECTORIES
+Upon startup, revdep searches the /etc/revdep.d directory for files named
+after ports. If any are found, any directories (assumed to be absolute
+pathes and delimited by newlines) within the file are added to a list of
+port specific directories to search if a library dependency is not found
+in one of the many standard locations (as specified by ld.so(8)).
+
+If a port is discovered to have library dependencies that are in a
+non-standard location, then a file, as specified above, should be created.
+
+For example, if the port "firefox" has a "libxul.so" dependency in a
+the non-standard directory "/usr/lib/firefox" then a file named "firefox"
+should be created under "/etc/revdep.d" with a single line containing
+"/usr/lib/firefox". This will tell revdep where to find firefox's "libxul.so"
+when looking for its library dependencies, reducing one source of false
+positives. Ideally, this file would be included with the port's own packaging
+as well.
 NOTES
-C rewrite inspired by Johannes Winkelmann's <jw@tks6.net> shell revdep.
+C++ rewrite inspired by Johannes Winkelmann's <jw@tks6.net> shell revdep.
 Contributed to design Danny Rawlins <contact@romster.me>.
 SEE ALSO
-ldd(1), prt-get(8), pkginfo(8)
+ld.so(8), prt-get(8), pkginfo(1)
 AUTHOR
 James Buren, ryuo @ freenode 
diff --git a/revdep/utility.c b/revdep/utility.c
deleted file mode 100644
index 67247e1..0000000
--- a/revdep/utility.c
+++ /dev/null
@@ -1,416 +0,0 @@
-// Copyright (C) 2015 James Buren
-//
-// This file is part of revdep.
-//
-// revdep is free software: you can redistribute it and/or modify
-// it under the terms of the GNU General Public License as published by
-// the Free Software Foundation, either version 3 of the License, or
-// (at your option) any later version.
-//
-// revdep is distributed in the hope that it will be useful,
-// but WITHOUT ANY WARRANTY; without even the implied warranty of
-// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-// GNU General Public License for more details.
-//
-// You should have received a copy of the GNU General Public License
-// along with revdep.  If not, see <http://www.gnu.org/licenses/>.
-
-#define _IN_UTILITY_
-#include "utility.h"
-#include "global.h"
-#include <stdlib.h>
-#include <stdio.h>
-#include <stdarg.h>
-#include <stdint.h>
-#include <string.h>
-#include <unistd.h>
-#include <fcntl.h>
-#include <sys/stat.h>
-#include <sys/mman.h>
-#include <errno.h>
-#include <gelf.h>
-#include <zlib.h>
-
-extern void *xmalloc(unsigned int bytes)
-{
-	void *p;
-
-	if(bytes == 0)
-	{
-		logger(LOG_BRIEF, "%s: bytes is zero\n", __func__);
-		abort();
-	}
-	
-	if((p = malloc(bytes)) == NULL)
-	{
-		logger(LOG_BRIEF, "%s: out of memory\n", __func__);
-		abort();
-	}
-
-	return p;
-}
-
-extern void *xrealloc(void *p, unsigned int bytes)
-{
-	if(p == NULL)
-	{
-		logger(LOG_BRIEF, "%s: p is NULL\n", __func__);
-		abort();
-	}
-
-	if(bytes == 0)
-	{
-		logger(LOG_BRIEF, "%s: bytes is zero\n", __func__);
-		abort();
-	}
-
-	if((p = realloc(p, bytes)) == NULL)
-	{
-		logger(LOG_BRIEF, "%s: out of memory\n", __func__);
-		abort();
-	}
-
-	return p;
-}
-
-extern char *xstrdup(const char *in)
-{
-	char *out;
-
-	if(in == NULL)
-	{
-		logger(LOG_BRIEF, "%s: s is NULL\n", __func__);
-		abort();
-	}
-
-	if((out = strdup(in)) == NULL)
-	{
-		logger(LOG_BRIEF, "%s: out of memory\n", __func__);
-		abort();
-	}
-
-	return out;
-}
-
-extern void logger(int level, const char *fmt, ...)
-{
-	va_list args;
-
-	if(level > rd.verbose)
-		return;
-
-	va_start(args, fmt);
-
-	vfprintf(stdout, fmt, args);
-
-	va_end(args);
-}
-
-extern char *strtrim(char *s)
-{
-	static const char SPACE[] = " \t\r\n\v\f";
-	unsigned int left;
-	unsigned int middle;
-	//unsigned int right;
-
-	left = strspn(s, SPACE);
-
-	middle = strcspn(s + left, SPACE);
-
-	//right = strspn(s + left + middle, SPACE);
-
-	memmove(s, s + left, middle);
-
-	s[middle] = '\0';
-
-	return s;
-}
-
-extern unsigned int string_crc32(const char *s)
-{
-	unsigned int hash;
-
-	if(s == NULL || s[0] == '\0')
-	{
-		errno = EINVAL;
-		return -1;
-	}
-
-	hash = crc32(0, Z_NULL, 0);
-
-	hash = crc32(hash, (Bytef *) s, strlen(s) + 1);
-
-	return hash;
-}
-
-extern int open_file_in_memory(const char *path, char **text, unsigned int *length)
-{
-	struct stat st;
-	int fd;
-
-	if(path == NULL || path[0] == '\0' || text == NULL || length == NULL)
-	{
-		errno = EINVAL;
-		return -1;
-	}
-
-	if((fd = open(path, O_RDONLY)) == -1)
-	{
-		return -1;
-	}
-
-	if(fstat(fd, &st) == -1)
-	{
-		close(fd);
-		return -1;
-	}
-
-	if((text[0] = mmap(NULL, st.st_size, PROT_READ, MAP_PRIVATE, fd, 0)) == NULL)
-	{
-		close(fd);
-		return -1;
-	}
-
-	// We don't need to keep the fd around.
-	close(fd);
-
-	length[0] = st.st_size;
-	
-	return 0;
-}
-
-extern void close_file_in_memory(char *text, unsigned int length)
-{
-	if(text == NULL || length == 0)
-		return;
-
-	munmap(text, length);
-}
-
-extern int parse_file_in_memory(char *text, parse_cb_t cb)
-{
-	static const char RS[] = "\n\n";
-	static const char FS[] = "\n";
-	char *r_start;
-	char *r_end;
-	char *f_start;
-	char *f_end;
-	int record;
-	int field;
-
-	if(text == NULL || text[0] == '\0' || cb == NULL)
-	{
-		errno = EINVAL;
-		return -1;
-	}
-
-	inline int next_record(void)
-	{
-		// Test for EOF.
-		// Return EOF if so.
-		if(r_start[0] == '\0')
-			return -1;
-
-		// Test for RS.
-		// Skip RS if so.
-		if(strncmp(r_start, RS, strlen(RS)) == 0)
-			r_start += strlen(RS);
-
-		// Find the RS.
-		// If RS is not found, then use the end of the file.
-		if((r_end = strstr(r_start, RS)) == NULL)
-			r_end = r_start + strlen(r_start);
-
-		return 0;
-	}
-
-	inline int next_field(void)
-	{
-		// Test for RS and EOF.
-		// Return EOF if either is found.
-		if(strncmp(f_start, RS, strlen(RS)) == 0 || strcmp(f_start, FS) == 0 || f_start[0] == '\0')
-			return -1;
-
-		// Test for FS.
-		// Skip FS if so.
-		if(f_start[0] == FS[0])
-			f_start += 1;
-
-		// Find the FS.
-		// If FS is not found, then use the end of the file.
-		if((f_end = strchr(f_start, FS[0])) == NULL)
-			f_end = f_start + strlen(f_start);
-
-		return 0;
-	}
-
-	for( r_start = text, record = 0 ; next_record() == 0 ; r_start = r_end, ++record )
-	{
-		for( f_start = r_start, field = 0 ; next_field() == 0 ; f_start = f_end, ++field )
-		{
-			cb(record, field, f_start, f_end);
-		}
-	}
-
-	return 0;
-}
-
-extern int get_ld_for_file(const char *pkg, const char *path, const char **ld)
-{
-	struct stat st;
-	int fd = -1;
-	Elf *elf = NULL;
-	GElf_Ehdr ehdr;
-	size_t i;
-	size_t phdrnum;
-	GElf_Phdr phdr;
-	int rv = -1;
-
-	if(pkg == NULL || pkg[0] == '\0' || path == NULL || path[0] == '\0' || ld == NULL)
-	{
-		errno = EINVAL;
-		goto bail;
-	}
-
-	if(lstat(path, &st) == -1)
-	{
-		logger(LOG_ERROR, "%s:%s: could not stat file\n", pkg, path);
-		goto bail;
-	}
-
-	if(!S_ISREG(st.st_mode))
-	{
-		goto bail;
-	}
-
-	if((fd = open(path, O_RDONLY)) == -1)
-	{
-		logger(LOG_ERROR, "%s:%s: could not open file\n", pkg, path);
-		goto bail;
-	}
-
-	if((elf = elf_begin(fd, ELF_C_READ_MMAP, NULL)) == NULL)
-	{
-		goto bail;
-	}
-
-	if(elf_kind(elf) != ELF_K_ELF)
-	{
-		goto bail;
-	}
-
-	if(gelf_getehdr(elf, &ehdr) == NULL)
-	{
-		goto bail;
-	}
-
-	// Check if file is executable or shared library
-	switch(ehdr.e_type)
-	{
-		case ET_EXEC:
-			break;
-
-		case ET_DYN:
-			break;
-
-		default:
-			goto bail;
-	}
-
-	// Check if file has SYSTEMV or LINUX ABI
-	switch(ehdr.e_ident[EI_OSABI])
-	{
-		case ELFOSABI_NONE:
-			break;
-
-		case ELFOSABI_LINUX:
-			break;
-
-		default:
-			goto bail;
-	}
-
-	// Check if file is supported by this host's architecture
-	switch(ehdr.e_machine)
-	{
-
-#if defined(__i386__) || defined(__x86_64__)
-		case EM_386:
-			break;
-#endif
-
-#if defined(__x86_64__)
-		case EM_X86_64:
-			break;
-#endif
-
-#if defined(__arm__)
-		case EM_ARM:
-			break;
-#endif
-
-		default:
-			goto bail;
-
-	}
-
-	// Check if file has a dynamic section
-	if(elf_getphdrnum(elf, &phdrnum) == -1)
-	{
-		goto bail;
-	}
-
-	for( i = 0 ; i < phdrnum ; ++i )
-	{
-		if(gelf_getphdr(elf, i, &phdr) != NULL && phdr.p_type == PT_DYNAMIC)
-		{
-			break;
-		}
-	}
-
-	// If true, then a dynamic section was not found.
-	if(i == phdrnum)
-	{
-		goto bail;
-	}
-
-	// Check if file has a known LD binary
-	switch(ehdr.e_ident[EI_CLASS])
-	{
-
-#if defined(__i386__)
-		case ELFCLASS32:
-			ld[0] = "/lib/ld-linux.so.2";
-			break;
-#elif defined(__x86_64__)
-		case ELFCLASS32:
-			ld[0] = "/lib32/ld-linux.so.2";
-			break;
-		case ELFCLASS64:
-			ld[0] = "/lib/ld-linux-x86-64.so.2";
-			break;
-#elif defined(__arm__)
-		case ELFCLASS32:
-			ld[0] = "/lib/ld-linux-armhf.so.3";
-			break;
-#else
-#error "Unsupported Architecture"
-#endif
-
-		default:
-			goto bail;
-
-	}
-
-	rv = 0;
-
-bail:
-
-	if(elf != NULL)
-		elf_end(elf);
-
-	if(fd != -1)
-		close(fd);
-
-	return rv;
-}
diff --git a/revdep/utility.cpp b/revdep/utility.cpp
new file mode 100644
index 0000000..24fd12f
--- /dev/null
+++ b/revdep/utility.cpp
@@ -0,0 +1,108 @@
+// Copyright (C) 2016 James Buren
+//
+// This file is part of revdep.
+//
+// revdep is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// revdep is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with revdep.  If not, see <http://www.gnu.org/licenses/>.
+
+#include "utility.h"
+#include <fstream>
+#include <glob.h>
+#include <sys/stat.h>
+
+void split(const std::string &in, StringVector &out, char delimiter) {
+	size_t i = 0;
+	size_t j = in.find(delimiter);
+
+	while(j != std::string::npos) {
+		out.push_back(in.substr(i, j - i));
+		i = ++j;
+		j = in.find(delimiter, j);
+	}
+
+	out.push_back(in.substr(i));
+}
+
+void ReadRdConf(const std::string &path, StringVector &dirs) {
+	std::ifstream fin;
+
+	fin.open(path.c_str());
+
+	if(!fin.is_open()) {
+		return;
+	}
+
+	std::string line;
+
+	while(getline(fin, line)) {
+		if(line[0] != '#' && line.length() > 0) {
+			dirs.push_back(line);
+		}
+	}
+
+	fin.close();
+}
+
+bool ReadLdConf(const std::string &path, StringVector &dirs, int maxDepth) {
+	if(maxDepth <= 0) {
+		return false;
+	}
+
+	std::ifstream fin;
+
+	fin.open(path.c_str());
+
+	if(!fin.is_open()) {
+		return false;
+	}
+
+	std::string line;
+
+	while(getline(fin, line)) {
+		if(line[0] == '#') {
+			continue;
+		}
+
+		if(line.compare(0, 8, "include ") == 0) {
+			glob_t g;
+
+			if(glob(line.substr(8).c_str(), 0, NULL, &g) == 0) {
+				for( size_t i = 0 ; i < g.gl_pathc ; ++i ) {
+					if(!ReadLdConf(g.gl_pathv[i], dirs, maxDepth - 1)) {
+						globfree(&g);
+						fin.close();
+						return false;
+					}
+				}
+			}
+
+			globfree(&g);
+		} else if(line.length() > 0) {
+			dirs.push_back(line);
+		}
+	}
+
+	fin.close();
+
+	return true;
+}
+
+bool IsFile(const std::string &path) {
+	struct stat st;
+
+	if(lstat(path.c_str(), &st) == -1) {
+		return false;
+	}
+
+	return S_ISREG(st.st_mode);
+}
diff --git a/revdep/utility.h b/revdep/utility.h
index 34c02b1..b79484e 100644
--- a/revdep/utility.h
+++ b/revdep/utility.h
@@ -1,4 +1,4 @@
-// Copyright (C) 2015 James Buren
+// Copyright (C) 2016 James Buren
 //
 // This file is part of revdep.
 //
@@ -17,27 +17,12 @@
 
 #pragma once
 
-#define new(T,N)     ((T*)xmalloc(sizeof(T)*(N)))
-#define renew(P,T,N) ((T*)xrealloc((P),sizeof(T)*(N)))
+#include <vector>
+#include <string>
 
-typedef void (*parse_cb_t) (int record, int field, char *start, char *end);
+typedef std::vector <std::string> StringVector;
 
-enum
-{
-	LOG_BRIEF,
-	LOG_INFO_1,
-	LOG_INFO_2,
-	LOG_ERROR,
-	LOG_DEBUG
-};
-
-extern void *xmalloc(unsigned int bytes);
-extern void *xrealloc(void *p, unsigned int bytes);
-extern char *xstrdup(const char *in);
-extern void logger(int level, const char *fmt, ...) __attribute__((format(printf,2,3)));
-extern char *strtrim(char *s);
-extern unsigned int string_crc32(const char *s);
-extern int open_file_in_memory(const char *path, char **text, unsigned int *length);
-extern void close_file_in_memory(char *text, unsigned int length);
-extern int parse_file_in_memory(char *text, parse_cb_t cb);
-extern int get_ld_for_file(const char *pkg, const char *path, const char **ld);
+void split(const std::string &in, StringVector &out, char delimiter);
+void ReadRdConf(const std::string &path, StringVector &dirs);
+bool ReadLdConf(const std::string &path, StringVector &dirs, int maxDepth);
+bool IsFile(const std::string &path);