diff --git a/man/systemd-delta.xml b/man/systemd-delta.xml
new file mode 100644
index 00000000000..0e06b48fcc3
--- /dev/null
+++ b/man/systemd-delta.xml
@@ -0,0 +1,120 @@
+
+
+
+
+
+
+
+
+ systemd-delta
+ systemd
+
+
+
+ Developer
+ Lennart
+ Poettering
+ lennart@poettering.net
+
+
+
+
+
+ systemd-delta
+ 1
+
+
+
+ systemd-delta
+ Find overridden configuration files
+
+
+
+
+ systemd-delta OPTIONS SUFFIX
+
+
+
+
+ Description
+
+ systemd-delta may be used to
+ identify and compare configuration files in
+ /etc that override default
+ counterparts in /usr. The command
+ line argument can be one or more name of a subdirectories of
+ /etc or
+ /usr/lib to compare, such as
+ tmpfiles.d, sysctl.d or
+ systemd/system.
+
+ When no argument is specified a number of
+ well-known subdirectories are searched for overriden
+ files.
+
+
+
+ Options
+
+ The following options are understood:
+
+
+
+
+
+
+ Prints a short help
+ text and exits.
+
+
+
+
+
+ Prints a short version
+ string and exits.
+
+
+
+
+
+ Do not pipe output into a
+ pager.
+
+
+
+
+
+
+
+ Exit status
+
+ On success 0 is returned, a non-zero failure
+ code otherwise.
+
+
+
+ See Also
+
+ systemd1
+
+
+
+
diff --git a/src/delta/Makefile b/src/delta/Makefile
new file mode 120000
index 00000000000..d0b0e8e0086
--- /dev/null
+++ b/src/delta/Makefile
@@ -0,0 +1 @@
+../Makefile
\ No newline at end of file
diff --git a/src/delta/delta.c b/src/delta/delta.c
new file mode 100644
index 00000000000..65e720e4eb9
--- /dev/null
+++ b/src/delta/delta.c
@@ -0,0 +1,390 @@
+/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
+
+/***
+ This file is part of systemd.
+
+ Copyright 2012 Lennart Poettering
+
+ systemd is free software; you can redistribute it and/or modify it
+ under the terms of the GNU Lesser General Public License as published by
+ the Free Software Foundation; either version 2.1 of the License, or
+ (at your option) any later version.
+
+ systemd 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
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public License
+ along with systemd; If not, see .
+***/
+
+#include
+#include
+#include
+#include
+#include
+
+#include "hashmap.h"
+#include "util.h"
+#include "path-util.h"
+#include "log.h"
+#include "pager.h"
+#include "build.h"
+
+static bool arg_no_pager = false;
+
+static int equivalent(const char *a, const char *b) {
+ char *x, *y;
+ int r;
+
+ x = canonicalize_file_name(a);
+ if (!x)
+ return -errno;
+
+ y = canonicalize_file_name(b);
+ if (!y) {
+ free(x);
+ return -errno;
+ }
+
+ r = path_equal(x, y);
+ free(x);
+ free(y);
+
+ return r;
+}
+
+static int found_override(const char *top, const char *bottom) {
+ char *dest;
+ int k;
+ pid_t pid;
+
+ assert(top);
+ assert(bottom);
+
+ if (null_or_empty_path(top) > 0) {
+ printf(ANSI_HIGHLIGHT_RED_ON "[MASK]" ANSI_HIGHLIGHT_OFF " %s → %s\n", top, bottom);
+ goto finish;
+ }
+
+ k = readlink_malloc(top, &dest);
+ if (k >= 0) {
+ if (equivalent(dest, bottom) > 0)
+ printf(ANSI_HIGHLIGHT_GREEN_ON "[EQUIVALENT]" ANSI_HIGHLIGHT_OFF " %s → %s\n", top, bottom);
+ else
+ printf(ANSI_HIGHLIGHT_ON "[REDIRECT]" ANSI_HIGHLIGHT_OFF " %s → %s\n", top, bottom);
+
+ free(dest);
+ goto finish;
+ }
+
+ printf(ANSI_HIGHLIGHT_ON "[OVERRIDE]" ANSI_HIGHLIGHT_OFF " %s → %s\n", top, bottom);
+
+ putchar('\n');
+
+ fflush(stdout);
+
+ pid = fork();
+ if (pid < 0) {
+ log_error("Failed to fork off diff: %m");
+ return -errno;
+ } else if (pid == 0) {
+ execlp("diff", "diff", "-us", "--", bottom, top, NULL);
+ log_error("Failed to execute diff: %m");
+ _exit(1);
+ }
+
+ wait_for_terminate(pid, NULL);
+
+ putchar('\n');
+
+finish:
+
+ return 0;
+}
+
+static int enumerate_dir(Hashmap *top, Hashmap *bottom, const char *path) {
+ DIR *d;
+ int r = 0;
+
+ assert(top);
+ assert(bottom);
+ assert(path);
+
+ d = opendir(path);
+ if (!d) {
+ if (errno == ENOENT)
+ return 0;
+
+ log_error("Failed to enumerate %s: %m", path);
+ return -errno;
+ }
+
+ for (;;) {
+ struct dirent *de, buf;
+ int k;
+ char *p;
+
+ k = readdir_r(d, &buf, &de);
+ if (k != 0) {
+ r = -k;
+ goto finish;
+ }
+
+ if (!de)
+ break;
+
+ if (!dirent_is_file(de))
+ continue;
+
+ p = join(path, "/", de->d_name, NULL);
+ if (!p) {
+ r = -ENOMEM;
+ goto finish;
+ }
+
+ path_kill_slashes(p);
+
+ k = hashmap_put(top, path_get_file_name(p), p);
+ if (k >= 0) {
+ p = strdup(p);
+ if (!p) {
+ r = -ENOMEM;
+ goto finish;
+ }
+ } else if (k != -EEXIST) {
+ free(p);
+ r = k;
+ goto finish;
+ }
+
+ free(hashmap_remove(bottom, path_get_file_name(p)));
+ k = hashmap_put(bottom, path_get_file_name(p), p);
+ if (k < 0) {
+ free(p);
+ r = k;
+ goto finish;
+ }
+ }
+
+finish:
+ closedir(d);
+
+ return r;
+}
+
+static int process_suffix(const char *prefixes, const char *suffix) {
+ const char *p;
+ char *f;
+ Hashmap *top, *bottom;
+ int r = 0, k;
+ Iterator i;
+ int n_found = 0;
+
+ assert(prefixes);
+ assert(suffix);
+
+ top = hashmap_new(string_hash_func, string_compare_func);
+ if (!top) {
+ r = -ENOMEM;
+ goto finish;
+ }
+
+ bottom = hashmap_new(string_hash_func, string_compare_func);
+ if (!bottom) {
+ r = -ENOMEM;
+ goto finish;
+ }
+
+ NULSTR_FOREACH(p, prefixes) {
+ char *t;
+
+ t = join(p, "/", suffix, NULL);
+ if (!t) {
+ r = -ENOMEM;
+ goto finish;
+ }
+
+ k = enumerate_dir(top, bottom, t);
+ if (k < 0)
+ r = k;
+
+ log_debug("Looking at %s", t);
+ free(t);
+ }
+
+ HASHMAP_FOREACH(f, top, i) {
+ char *o;
+
+ o = hashmap_get(bottom, path_get_file_name(f));
+ assert(o);
+
+ if (path_equal(o, f))
+ continue;
+
+ k = found_override(f, o);
+ if (k < 0)
+ r = k;
+
+ n_found ++;
+ }
+
+finish:
+ if (top)
+ hashmap_free_free(top);
+ if (bottom)
+ hashmap_free_free(bottom);
+
+ return r < 0 ? r : n_found;
+}
+
+static int process_suffix_chop(const char *prefixes, const char *suffix) {
+ const char *p;
+
+ assert(prefixes);
+ assert(suffix);
+
+ if (!path_is_absolute(suffix))
+ return process_suffix(prefixes, suffix);
+
+ /* Strip prefix from the suffix */
+ NULSTR_FOREACH(p, prefixes) {
+ if (startswith(suffix, p)) {
+ suffix += strlen(p);;
+ suffix += strspn(suffix, "/");
+ return process_suffix(prefixes, suffix);
+ }
+ }
+
+ log_error("Invalid suffix specification %s.", suffix);
+ return -EINVAL;
+}
+
+static void help(void) {
+
+ printf("%s [OPTIONS...] [SUFFIX...]\n\n"
+ "Find overridden configuration files.\n\n"
+ " -h --help Show this help\n"
+ " --version Show package version\n"
+ " --no-pager Do not pipe output into a pager\n",
+ program_invocation_short_name);
+}
+
+static int parse_argv(int argc, char *argv[]) {
+
+ enum {
+ ARG_NO_PAGER = 0x100,
+ ARG_VERSION
+ };
+
+ static const struct option options[] = {
+ { "help", no_argument, NULL, 'h' },
+ { "version", no_argument, NULL, ARG_VERSION },
+ { "no-pager", no_argument, NULL, ARG_NO_PAGER },
+ { NULL, 0, NULL, 0 }
+ };
+
+ int c;
+
+ assert(argc >= 1);
+ assert(argv);
+
+ while ((c = getopt_long(argc, argv, "h", options, NULL)) >= 0) {
+
+ switch (c) {
+
+ case 'h':
+ help();
+ return 0;
+
+ case ARG_VERSION:
+ puts(PACKAGE_STRING);
+ puts(DISTRIBUTION);
+ puts(SYSTEMD_FEATURES);
+ return 0;
+
+ case ARG_NO_PAGER:
+ arg_no_pager = true;
+ break;
+
+ case '?':
+ return -EINVAL;
+
+ default:
+ log_error("Unknown option code %c", c);
+ return -EINVAL;
+ }
+ }
+
+ return 1;
+}
+
+int main(int argc, char *argv[]) {
+
+ const char prefixes[] =
+ "/etc\0"
+ "/run\0"
+ "/usr/local/lib\0"
+ "/usr/local/share\0"
+ "/usr/lib\0"
+ "/usr/share\0"
+#ifdef HAVE_SPLIT_USR
+ "/lib\0"
+#endif
+ ;
+
+ const char suffixes[] =
+ "sysctl.d\0"
+ "tmpfiles.d\0"
+ "modules-load.d\0"
+ "systemd/system\0"
+ "systemd/user\0"
+ "binfmt.d\0"
+ "udev/rules.d\0"
+ "modprobe.d\0";
+
+ int r = 0, k;
+ int n_found = 0;
+
+ log_parse_environment();
+ log_open();
+
+ r = parse_argv(argc, argv);
+ if (r <= 0)
+ goto finish;
+
+ if (!arg_no_pager)
+ pager_open();
+
+ if (optind < argc) {
+ int i;
+
+ for (i = optind; i < argc; i++) {
+ k = process_suffix_chop(prefixes, argv[i]);
+ if (k < 0)
+ r = k;
+ else
+ n_found += k;
+ }
+
+ } else {
+ const char *n;
+
+ NULSTR_FOREACH(n, suffixes) {
+ k = process_suffix(prefixes, n);
+ if (k < 0)
+ r = k;
+ else
+ n_found += k;
+ }
+ }
+
+ if (r >= 0)
+ printf("\n%i overriden configuration files found.\n", n_found);
+
+finish:
+ pager_close();
+
+ return r < 0 ? EXIT_FAILURE : EXIT_SUCCESS;
+}