libbb: [x]fopen_for_{read,write} introduced and used.

 (by Valdimir)

function                                             old     new   delta
config_open2                                           -      41     +41
config_read                                          507     542     +35
find_pair                                            169     187     +18
fopen_for_write                                        -      14     +14
fopen_for_read                                         -      14     +14
find_main                                            406     418     +12
xfopen_for_write                                       -      10     +10
xfopen_for_read                                        -      10     +10
popstring                                            134     140      +6
parse_inittab                                        396     401      +5
next_token                                           923     928      +5
pack_gzip                                           1659    1661      +2
bb__parsespent                                       117     119      +2
fallbackSort                                        1719    1717      -2
evalvar                                             1376    1374      -2
qrealloc                                              36      33      -3
...
...
...
...
singlemount                                         4579    4569     -10
process_stdin                                        443     433     -10
patch_main                                          1111    1101     -10
ifupdown_main                                       2175    2165     -10
file_action_grep                                      90      80     -10
uuidcache_init                                       649     637     -12
hush_main                                            797     785     -12
read_config                                          230     217     -13
dpkg_main                                           3835    3820     -15
read_line_input                                     3134    3110     -24
sysctl_main                                          232     203     -29
config_open                                           40      10     -30
WARN_BAD_LINE                                         44       -     -44
login_main                                          1714    1575    -139
------------------------------------------------------------------------------
(add/remove: 5/1 grow/shrink: 8/74 up/down: 174/-737)        Total: -563 bytes

1 files changed, 5 insertions, 16 deletions

diff --git a/util-linux/hexdump.c b/util-linux/hexdump.c
index 4d2b0592b..8ac12f082 100644
--- a/util-linux/hexdump.c
+++ b/util-linux/hexdump.c
@@ -14,24 +14,13 @@
 
 /* This is a NOEXEC applet. Be very careful! */
 
-
 static void bb_dump_addfile(dumper_t *dumper, char *name)
 {
-        char *p;
-        FILE *fp;
-        char *buf;
-
-        fp = xfopen(name, "r");
-
-        while ((buf = xmalloc_fgetline(fp)) != NULL) {
-                p = skip_whitespace(buf);
-
-                if (*p && (*p != '#')) {
-                        bb_dump_add(dumper, p);
-                }
-                free(buf);
+        parser_t *parser = config_open2(name, xfopen_for_read);
+        while (config_read(parser, &name, 1, 1, "# \t", 0)) {
+                bb_dump_add(dumper, name);
         }
-        fclose(fp);
+        config_close(parser);
 }
 
 static const char *const add_strings[] = {
@@ -131,7 +120,7 @@ int hexdump_main(int argc, char **argv)
 
         do {
                 char *buf;
-                fp = xfopen(*argv, "r");
+                fp = xfopen_for_read(*argv);
  jump_in:
                 while ((buf = xmalloc_fgetline(fp)) != NULL) {
                         p = buf;