mv: implement -n option

function                                             old     new   delta
mv_longopts                                           23      36     +13
mv_main                                              510     520     +10
packed_usage                                       27218   27225      +7

Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com>

2 files changed, 33 insertions, 25 deletions

diff --git a/coreutils/mv.c b/coreutils/mv.c
index 7f49d5bab..245639bd0 100644
--- a/coreutils/mv.c
+++ b/coreutils/mv.c
@@ -16,15 +16,30 @@
 #include "libbb.h"
 #include "libcoreutils/coreutils.h"
 
+//usage:#define mv_trivial_usage
+//usage:       "[-fin] SOURCE DEST\n"
+//usage:       "or: mv [-fin] SOURCE... DIRECTORY"
+//usage:#define mv_full_usage "\n\n"
+//usage:       "Rename SOURCE to DEST, or move SOURCE(s) to DIRECTORY\n"
+//usage:     "\nOptions:"
+//usage:     "\n        -f      Don't prompt before overwriting"
+//usage:     "\n        -i      Interactive, prompt before overwrite"
+//usage:     "\n        -n      Don't overwrite an existing file"
+//usage:
+//usage:#define mv_example_usage
+//usage:       "$ mv /tmp/foo /bin/bar\n"
+
 #if ENABLE_FEATURE_MV_LONG_OPTIONS
 static const char mv_longopts[] ALIGN1 =
         "interactive\0" No_argument "i"
         "force\0"       No_argument "f"
+        "no-clobber\0"  No_argument "n"
         ;
 #endif
 
 #define OPT_FILEUTILS_FORCE       1
 #define OPT_FILEUTILS_INTERACTIVE 2
+#define OPT_FILEUTILS_NOCLOBBER   4
 
 int mv_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
 int mv_main(int argc, char **argv)
@@ -40,10 +55,11 @@ int mv_main(int argc, char **argv)
 #if ENABLE_FEATURE_MV_LONG_OPTIONS
         applet_long_options = mv_longopts;
 #endif
-        // Need at least two arguments
-        // -f unsets -i, -i unsets -f
-        opt_complementary = "-2:f-i:i-f";
-        flags = getopt32(argv, "fi");
+        /* Need at least two arguments.
+         * If more than one of -f, -i, -n is specified , only the final one
+         * takes effect (it unsets previous options). */
+        opt_complementary = "-2:f-in:i-fn:n-fi";
+        flags = getopt32(argv, "fin");
         argc -= optind;
         argv += optind;
         last = argv[argc - 1];
@@ -68,18 +84,22 @@ int mv_main(int argc, char **argv)
                 }
 
  DO_MOVE:
-                if (dest_exists
-                 && !(flags & OPT_FILEUTILS_FORCE)
-                 && ((access(dest, W_OK) < 0 && isatty(0))
-                    || (flags & OPT_FILEUTILS_INTERACTIVE))
-                ) {
-                        if (fprintf(stderr, "mv: overwrite '%s'? ", dest) < 0) {
-                                goto RET_1;     /* Ouch! fprintf failed! */
-                        }
-                        if (!bb_ask_confirmation()) {
+                if (dest_exists) {
+                        if (flags & OPT_FILEUTILS_NOCLOBBER)
                                 goto RET_0;
+                        if (!(flags & OPT_FILEUTILS_FORCE)
+                         && ((access(dest, W_OK) < 0 && isatty(0))
+                            || (flags & OPT_FILEUTILS_INTERACTIVE))
+                        ) {
+                                if (fprintf(stderr, "mv: overwrite '%s'? ", dest) < 0) {
+                                        goto RET_1;     /* Ouch! fprintf failed! */
+                                }
+                                if (!bb_ask_confirmation()) {
+                                        goto RET_0;
+                                }
                         }
                 }
+
                 if (rename(*argv, dest) < 0) {
                         struct stat source_stat;
                         int source_exists;
diff --git a/include/usage.src.h b/include/usage.src.h
index f5ddd7ba5..e1810c977 100644
--- a/include/usage.src.h
+++ b/include/usage.src.h
@@ -2695,18 +2695,6 @@ INSERT
        "ras3 reset retension rewind rewoffline seek setblk setdensity\n" \
        "setpart tell unload unlock weof wset" \
 
-#define mv_trivial_usage \
-       "[-fi] SOURCE DEST\n" \
-       "or: mv [-fi] SOURCE... DIRECTORY"
-#define mv_full_usage "\n\n" \
-       "Rename SOURCE to DEST, or move SOURCE(s) to DIRECTORY\n" \
-     "\nOptions:" \
-     "\n        -f      Don't prompt before overwriting" \
-     "\n        -i      Interactive, prompt before overwrite" \
-
-#define mv_example_usage \
-       "$ mv /tmp/foo /bin/bar\n"
-
 #define nameif_trivial_usage \
        "[-s] [-c FILE] [{IFNAME MACADDR}]"
 #define nameif_full_usage "\n\n" \