binfmt,tmpfiles,modules-load,sysctl: rework the various early-boot services that work on .d/ directories

This unifies much of the logic behind them:

- All four will now ofllow the rule that the earlier file and earlier
  assignment in the .d/ directories wins. Before, sysctl was the only
  outlier, where the later setting always won.

- All four now support getopt() and --help on the command line.

- All four can now handle specification of configuration file names on
  the command line to apply. The tools will automatically find them, and
  apply them. Previously only tmpfiles could do that. This is useful for
  %post scripts in RPMs and suchlike.

- This fixes various error path issues in conf_files_list()

1 files changed, 3 insertions, 0 deletions

diff --git a/src/shared/util.h b/src/shared/util.h
index d926b01919..cd13457528 100644
--- a/src/shared/util.h
+++ b/src/shared/util.h
@@ -568,6 +568,9 @@ char *strip_tab_ansi(char **p, size_t *l);
 
 int on_ac_power(void);
 
+int search_and_fopen(const char *path, const char *mode, const char **search, FILE **_f);
+int search_and_fopen_nulstr(const char *path, const char *mode, const char *search, FILE **_f);
+
 #define FOREACH_LINE(f, line, on_error)                         \
         for (char line[LINE_MAX]; !feof(f); )                   \
                 if (!fgets(line, sizeof(line), f)) {            \