touch: support -r REF_FILE if ENABLE_DESKTOP (needed for blackfin compile)

function                                             old     new   delta
touch_main                                           136     221     +85

1 files changed, 39 insertions, 6 deletions

diff --git a/coreutils/touch.c b/coreutils/touch.c
index 0b58179e7..78ae4a5c3 100644
--- a/coreutils/touch.c
+++ b/coreutils/touch.c
@@ -21,24 +21,55 @@
 
 /* This is a NOFORK applet. Be very careful! */
 
+/* coreutils implements:
+ * -a   change only the access time
+ * -c, --no-create
+ *      do not create any files
+ * -d, --date=STRING
+ *      parse STRING and use it instead of current time
+ * -f   (ignored, BSD compat)
+ * -m   change only the modification time
+ * -r, --reference=FILE
+ *      use this file's times instead of current time
+ * -t STAMP
+ *      use [[CC]YY]MMDDhhmm[.ss] instead of current time
+ * --time=WORD
+ *      change the specified time: WORD is access, atime, or use
+ */
+
 int touch_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
 int touch_main(int argc ATTRIBUTE_UNUSED, char **argv)
 {
+#if ENABLE_DESKTOP
+        struct utimbuf timebuf;
+        char *reference_file = NULL;
+#else
+#define reference_file NULL
+#define timebuf        (*(struct utimbuf*)NULL)
+#endif
         int fd;
         int status = EXIT_SUCCESS;
-        int flags = getopt32(argv, "cf");
+        int flags = getopt32(argv, "c" USE_DESKTOP("r:")
+                                /*ignored:*/ "fma"
+                                USE_DESKTOP(, &reference_file));
 
-        flags &= 1; /* ignoring -f (BSD compat thingy) */
+        flags &= 1; /* only -c bit is left */
         argv += optind;
-
         if (!*argv) {
                 bb_show_usage();
         }
 
+        if (reference_file) {
+                struct stat stbuf;
+                xstat(reference_file, &stbuf);
+                timebuf.actime = stbuf.st_atime;
+                timebuf.modtime = stbuf.st_mtime;
+        }
+
         do {
-                if (utime(*argv, NULL)) {
-                        if (errno == ENOENT) {  /* no such file */
-                                if (flags) {    /* Creation is disabled, so ignore. */
+                if (utime(*argv, reference_file ? &timebuf : NULL)) {
+                        if (errno == ENOENT) { /* no such file */
+                                if (flags) { /* creation is disabled, so ignore */
                                         continue;
                                 }
                                 /* Try to create the file. */
@@ -46,6 +77,8 @@ int touch_main(int argc ATTRIBUTE_UNUSED, char **argv)
                                                   S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP | S_IROTH | S_IWOTH
                                                   );
                                 if ((fd >= 0) && !close(fd)) {
+                                        if (reference_file)
+                                                utime(*argv, &timebuf);
                                         continue;
                                 }
                         }