cp: add -u/--update and --remove-destination

Based on the patch by wdlkmpx@gmail.com

function                                             old     new   delta
copy_file                                           1546    1644     +98
add_partition                                       1270    1362     +92
ask_and_unlink                                        95     133     +38
do_iproute                                           132     157     +25
decode_one_format                                    710     715      +5
cp_main                                              369     374      +5
ubirename_main                                       198     202      +4
read_package_field                                   232     230      -2
bb_make_directory                                    421     412      -9
packed_usage                                       30505   30476     -29
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 7/3 up/down: 267/-40)           Total: 227 bytes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

1 files changed, 17 insertions, 7 deletions

diff --git a/include/libbb.h b/include/libbb.h
index fd40ef74c..a21f4204a 100644
--- a/include/libbb.h
+++ b/include/libbb.h
@@ -351,7 +351,7 @@ extern char *strrstr(const char *haystack, const char *needle) FAST_FUNC;
 //TODO: supply a pointer to char[11] buffer (avoid statics)?
 extern const char *bb_mode_string(mode_t mode) FAST_FUNC;
 extern int is_directory(const char *name, int followLinks) FAST_FUNC;
-enum {  /* DO NOT CHANGE THESE VALUES!  cp.c, mv.c, install.c depend on them. */
+enum {  /* cp.c, mv.c, install.c depend on these values. CAREFUL when changing them! */
         FILEUTILS_PRESERVE_STATUS = 1 << 0, /* -p */
         FILEUTILS_DEREFERENCE     = 1 << 1, /* !-d */
         FILEUTILS_RECUR           = 1 << 2, /* -R */
@@ -361,15 +361,25 @@ enum {	/* DO NOT CHANGE THESE VALUES!  cp.c, mv.c, install.c depend on them. */
         FILEUTILS_MAKE_SOFTLINK   = 1 << 6, /* -s */
         FILEUTILS_DEREF_SOFTLINK  = 1 << 7, /* -L */
         FILEUTILS_DEREFERENCE_L0  = 1 << 8, /* -H */
+        /* -a = -pdR (mapped in cp.c) */
+        /* -r = -dR  (mapped in cp.c) */
+        /* -P = -d   (mapped in cp.c) */
+        FILEUTILS_VERBOSE         = (1 << 12) * ENABLE_FEATURE_VERBOSE, /* -v */
+        FILEUTILS_UPDATE          = 1 << 13, /* -u */
 #if ENABLE_SELINUX
-        FILEUTILS_PRESERVE_SECURITY_CONTEXT = 1 << 9, /* -c */
-        FILEUTILS_SET_SECURITY_CONTEXT = 1 << 10,
+        FILEUTILS_PRESERVE_SECURITY_CONTEXT = 1 << 14, /* -c */
 #endif
-        FILEUTILS_IGNORE_CHMOD_ERR = 1 << 11,
-        /* -v */
-        FILEUTILS_VERBOSE         = (1 << 12) * ENABLE_FEATURE_VERBOSE,
+        FILEUTILS_RMDEST          = 1 << (15 - !ENABLE_SELINUX), /* --remove-destination */
+        /*
+         * Hole. cp may have some bits set here,
+         * they should not affect remove_file()/copy_file()
+         */
+#if ENABLE_SELINUX
+        FILEUTILS_SET_SECURITY_CONTEXT = 1 << 30,
+#endif
+        FILEUTILS_IGNORE_CHMOD_ERR = 1 << 31,
 };
-#define FILEUTILS_CP_OPTSTR "pdRfilsLH" IF_SELINUX("c")
+#define FILEUTILS_CP_OPTSTR "pdRfilsLHarPvu" IF_SELINUX("c")
 extern int remove_file(const char *path, int flags) FAST_FUNC;
 /* NB: without FILEUTILS_RECUR in flags, it will basically "cat"
  * the source, not copy (unless "source" is a directory).