[PATCH] cp: add -u/--update and --remove-destination

[wdlkmpx]

This matches the behavior of GNU coreutils
---
 coreutils/cp.c    | 14 +++++++++++---
 include/libbb.h   |  2 ++
 libbb/copy_file.c | 22 ++++++++++++++++++++++
 3 files changed, 35 insertions(+), 3 deletions(-)

diff --git a/coreutils/cp.c b/coreutils/cp.c
index 247ed0f..cd947be 100644
--- a/coreutils/cp.c
+++ b/coreutils/cp.c
@@ -31,6 +31,7 @@
 //usage:     "\n	-f	Overwrite"
 //usage:     "\n	-i	Prompt before overwrite"
 //usage:     "\n	-l,-s	Create (sym)links"
+//usage:     "\n	-u	Copy if SOURCE file is newer than the destination"
 
 #include "libbb.h"
 #include "libcoreutils/coreutils.h"
@@ -53,8 +54,10 @@ int cp_main(int argc, char **argv)
 		OPT_r = 1 << (sizeof(FILEUTILS_CP_OPTSTR)),
 		OPT_P = 1 << (sizeof(FILEUTILS_CP_OPTSTR)+1),
 		OPT_v = 1 << (sizeof(FILEUTILS_CP_OPTSTR)+2),
+		OPT_u = 1 << (sizeof(FILEUTILS_CP_OPTSTR)+3),
 #if ENABLE_FEATURE_CP_LONG_OPTIONS
-		OPT_parents = 1 << (sizeof(FILEUTILS_CP_OPTSTR)+3),
+		OPT_parents = 1 << (sizeof(FILEUTILS_CP_OPTSTR)+4),
+		OPT_rmdest  = 1 << (sizeof(FILEUTILS_CP_OPTSTR)+5),
 #endif
 	};
 
@@ -76,10 +79,12 @@ int cp_main(int argc, char **argv)
 		"recursive\0"      No_argument "R"
 		"symbolic-link\0"  No_argument "s"
 		"verbose\0"        No_argument "v"
-		"parents\0"        No_argument "\xff"
+		"update\0"         No_argument "u"
+		"parents\0"        No_argument "\xfe"
+		"remove-destination\0" No_argument "\xff"
 		;
 #endif
-	flags = getopt32(argv, FILEUTILS_CP_OPTSTR "arPv");
+	flags = getopt32(argv, FILEUTILS_CP_OPTSTR "arPvu");
 	/* Options of cp from GNU coreutils 6.10:
 	 * -a, --archive
 	 * -f, --force
@@ -161,6 +166,9 @@ int cp_main(int argc, char **argv)
 				bb_error_msg_and_die("with --parents, the destination must be a directory");
 			}
 		}
+		if (flags & OPT_rmdest) {
+			flags |= FILEUTILS_RMDEST;
+		}
 #endif
 
 		/* ...if neither is a directory...  */
diff --git a/include/libbb.h b/include/libbb.h
index fd40ef7..ece5f32 100644
--- a/include/libbb.h
+++ b/include/libbb.h
@@ -368,6 +368,8 @@ enum {	/* DO NOT CHANGE THESE VALUES!  cp.c, mv.c, install.c depend on them. */
 	FILEUTILS_IGNORE_CHMOD_ERR = 1 << 11,
 	/* -v */
 	FILEUTILS_VERBOSE         = (1 << 12) * ENABLE_FEATURE_VERBOSE,
+	FILEUTILS_UPDATE          = 1 << 13, /* -u */
+	FILEUTILS_RMDEST          = 1 << 14, /* cp --remove-destination */
 };
 #define FILEUTILS_CP_OPTSTR "pdRfilsLH" IF_SELINUX("c")
 extern int remove_file(const char *path, int flags) FAST_FUNC;
diff --git a/libbb/copy_file.c b/libbb/copy_file.c
index a4be875..44031f2 100644
--- a/libbb/copy_file.c
+++ b/libbb/copy_file.c
@@ -208,6 +208,28 @@ int FAST_FUNC copy_file(const char *source, const char *dest, int flags)
 			/* retval = -1; - WRONG! copy *WAS* made */
 		}
 		goto preserve_mode_ugid_time;
+	} else {
+		/* Not a directory */
+		if (dest_exists) {
+			if (flags & FILEUTILS_UPDATE) {
+				if (source_stat.st_mtime <= dest_stat.st_mtime) {
+					return 0; /* source file must be newer */
+				}
+			}
+			if (flags & FILEUTILS_RMDEST) {
+				if (unlink(dest) < 0) {
+					if (flags & FILEUTILS_VERBOSE) {
+						printf("can't remove '%s'\n", dest);
+					}
+					return -1;
+				} else {
+					if (flags & FILEUTILS_VERBOSE) {
+						printf("removed '%s'\n", dest);
+					}
+					dest_exists = 0;
+				}
+			}
+		}
 	}
 
 	if (flags & (FILEUTILS_MAKE_SOFTLINK|FILEUTILS_MAKE_HARDLINK)) {
-- 
2.8.3