touch: add SUSv3 options -a and -m

Add missing -a and -m options to be fully SUSv3 compliant.

function                                             old     new   delta
touch_main                                           415     510     +95
packed_usage                                       33824   33865     +41
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 2/0 up/down: 136/0)             Total: 136 bytes

v2: Ignore -a/-m if not ENABLE_FEATURE_TOUCH_SUSV3.

Signed-off-by: Xabier Oneca <xoneca@gmail.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

1 files changed, 45 insertions, 14 deletions

diff --git a/coreutils/touch.c b/coreutils/touch.c
index b30811157..dff68cb00 100644
--- a/coreutils/touch.c
+++ b/coreutils/touch.c
@@ -28,7 +28,7 @@
 //config:       This requires libc support for lutimes() function.
 //config:
 //config:config FEATURE_TOUCH_SUSV3
-//config:       bool "Add support for SUSV3 features (-d -t -r)"
+//config:       bool "Add support for SUSV3 features (-a -d -m -t -r)"
 //config:       default y
 //config:       depends on TOUCH
 //config:       help
@@ -38,11 +38,10 @@
 
 //kbuild:lib-$(CONFIG_TOUCH) += touch.o
 
-/* BB_AUDIT SUSv3 _NOT_ compliant -- options -a, -m not supported. */
-/* http://www.opengroup.org/onlinepubs/007904975/utilities/touch.html */
-
 //usage:#define touch_trivial_usage
-//usage:       "[-c]" IF_FEATURE_TOUCH_SUSV3(" [-d DATE] [-t DATE] [-r FILE]") " FILE..."
+//usage:       "[-c" IF_FEATURE_TOUCH_SUSV3("am") "]"
+//usage:       IF_FEATURE_TOUCH_SUSV3(" [-d DATE] [-t DATE] [-r FILE]")
+//usage:       " FILE..."
 //usage:#define touch_full_usage "\n\n"
 //usage:       "Update the last-modified date on the given FILE[s]\n"
 //usage:     "\n        -c      Don't create files"
@@ -50,6 +49,8 @@
 //usage:     "\n        -h      Don't follow links"
 //usage:        )
 //usage:        IF_FEATURE_TOUCH_SUSV3(
+//usage:     "\n        -a      Change only atime"
+//usage:     "\n        -m      Change only mtime"
 //usage:     "\n        -d DT   Date/time to use"
 //usage:     "\n        -t DT   Date/time to use"
 //usage:     "\n        -r FILE Use FILE's date/time"
@@ -92,9 +93,13 @@ int touch_main(int argc UNUSED_PARAM, char **argv)
                 OPT_r = (1 << 1) * ENABLE_FEATURE_TOUCH_SUSV3,
                 OPT_d = (1 << 2) * ENABLE_FEATURE_TOUCH_SUSV3,
                 OPT_t = (1 << 3) * ENABLE_FEATURE_TOUCH_SUSV3,
-                OPT_h = (1 << 4) * ENABLE_FEATURE_TOUCH_NODEREF,
+                OPT_a = (1 << 4) * ENABLE_FEATURE_TOUCH_SUSV3,
+                OPT_m = (1 << 5) * ENABLE_FEATURE_TOUCH_SUSV3,
+                OPT_h = (1 << 6) * ENABLE_FEATURE_TOUCH_NODEREF,
         };
 #if ENABLE_FEATURE_TOUCH_SUSV3
+        /* NULL = use current time */
+        const struct timeval *newtime = NULL;
 # if ENABLE_LONG_OPTS
         static const char touch_longopts[] ALIGN1 =
                 /* name, has_arg, val */
@@ -111,6 +116,7 @@ int touch_main(int argc UNUSED_PARAM, char **argv)
 # endif
         char *reference_file = NULL;
         char *date_str = NULL;
+        /* timebuf[0] is atime, timebuf[1] is mtime */
         struct timeval timebuf[2];
         timebuf[1].tv_usec = timebuf[0].tv_usec = 0;
 #else
@@ -124,9 +130,9 @@ int touch_main(int argc UNUSED_PARAM, char **argv)
         /* -d and -t both set time. In coreutils,
          * accepted data format differs a bit between -d and -t.
          * We accept the same formats for both */
-        opts = GETOPT32(argv, "c" IF_FEATURE_TOUCH_SUSV3("r:d:t:")
+        opts = GETOPT32(argv, "c" IF_FEATURE_TOUCH_SUSV3("r:d:t:am")
                                 IF_FEATURE_TOUCH_NODEREF("h")
-                                /*ignored:*/ "fma"
+                                /*ignored:*/ "f" IF_NOT_FEATURE_TOUCH_SUSV3("am")
                                 LONGOPTS
                                 IF_FEATURE_TOUCH_SUSV3(, &reference_file)
                                 IF_FEATURE_TOUCH_SUSV3(, &date_str)
@@ -146,6 +152,7 @@ int touch_main(int argc UNUSED_PARAM, char **argv)
                  * (or is it .st_mtimensec?? see date.c)
                  * to set microseconds too.
                  */
+                newtime = timebuf;
         }
 
         if (date_str) {
@@ -163,15 +170,39 @@ int touch_main(int argc UNUSED_PARAM, char **argv)
                 t = validate_tm_time(date_str, &tm_time);
 
                 timebuf[1].tv_sec = timebuf[0].tv_sec = t;
+                newtime = timebuf;
+        }
+
+        if ((opts & (OPT_a | OPT_m)) && !newtime) {
+                time(&timebuf[0].tv_sec);
+                timebuf[1].tv_sec = timebuf[0].tv_sec;
+                newtime = timebuf;
         }
 
         do {
                 int result;
-                result = (
-#if ENABLE_FEATURE_TOUCH_NODEREF
-                        (opts & OPT_h) ? lutimes :
-#endif
-                        utimes)(*argv, (reference_file || date_str) ? timebuf : NULL);
+
+                if (opts & (OPT_a | OPT_m)) {
+                        /* Save original times */
+                        struct stat stbuf;
+                        if (stat(*argv, &stbuf) == 0) {
+                                /* As we must set both times, we lose original
+                                 * file time microseconds.
+                                 * Can use .st_mtim.tv_nsec
+                                 * (or is it .st_mtimensec?? see date.c)
+                                 * to set microseconds too.
+                                 * Also, utimensat(2) allows to omit one of the
+                                 * times to be set. But it is SUSv4.
+                                 */
+                                if (!(opts & OPT_a))
+                                        timebuf[0].tv_sec = stbuf.st_atime;
+                                if (!(opts & OPT_m))
+                                        timebuf[1].tv_sec = stbuf.st_mtime;
+                        }
+                }
+
+                result = (ENABLE_FEATURE_TOUCH_NODEREF && (opts & OPT_h) ? lutimes : utimes)(*argv, newtime);
+
                 if (result != 0) {
                         if (errno == ENOENT) { /* no such file? */
                                 if (opts & OPT_c) {
@@ -183,7 +214,7 @@ int touch_main(int argc UNUSED_PARAM, char **argv)
                                 if (fd >= 0) {
                                         xclose(fd);
                                         if (reference_file || date_str)
-                                                utimes(*argv, timebuf);
+                                                utimes(*argv, newtime);
                                         continue;
                                 }
                         }