43800: Add nanosecond support to strftime built-in

ChangeLog

@@ -1,3 +1,8 @@
+2018-11-13  dana  <dana@dana.is>
+
+	* 43800: Doc/Zsh/mod_datetime.yo, Src/Modules/datetime.c,
+	Test/V09datetime.ztst: Add nanosecond support to strftime built-in
+
 2018-11-12  Oliver Kiddle  <okiddle@yahoo.co.uk>
 
 	* 43819: Completion/Unix/Command/_adb: expand adb completion to

Doc/Zsh/mod_datetime.yo

@@ -6,9 +6,13 @@ The tt(zsh/datetime) module makes available one builtin command:
 startitem()
 findex(strftime)
 cindex(date string, printing)
-xitem(tt(strftime) [ tt(-s) var(scalar) ] var(format) var(epochtime) )
+xitem(tt(strftime) [ tt(-s) var(scalar) ] var(format) [ var(epochtime) [ var(nanoseconds) ] ] )
 item(tt(strftime) tt(-r) [ tt(-q) ] [ tt(-s) var(scalar) ] var(format) var(timestring) )(
-Output the date denoted by var(epochtime) in the var(format) specified.
+Output the date in the var(format) specified.  With no var(epochtime), the
+current system date/time is used; optionally, var(epochtime) may be used to
+specify the number of seconds since the epoch, and var(nanoseconds) may
+additionally be used to specify the number of nanoseconds past the second
+(otherwise that number is assumed to be 0).
 See manref(strftime)(3) for details.  The zsh extensions described in
 ifzman(the section EXPANSION OF PROMPT SEQUENCES in zmanref(zshmisc))\
 ifnzman(noderef(Prompt Expansion)) are also available.

Src/Modules/datetime.c

@@ -100,8 +100,8 @@ output_strftime(char *nam, char **argv, Options ops, UNUSED(int func))
 {
     int bufsize, x, len;
     char *endptr = NULL, *scalar = NULL, *buffer;
-    time_t secs;
-    struct tm *t;
+    struct tm *tm;
+    struct timespec ts;
 
     if (OPT_ISSET(ops,'s')) {
 	scalar = OPT_ARG(ops, 's');
@@ -110,30 +110,58 @@ output_strftime(char *nam, char **argv, Options ops, UNUSED(int func))
 	    return 1;
 	}
     }
-    if (OPT_ISSET(ops, 'r'))
+    if (OPT_ISSET(ops, 'r')) {
+	if (!argv[1]) {
+	    zwarnnam(nam, "timestring expected");
+	    return 1;
+	}
 	return reverse_strftime(nam, argv, scalar, OPT_ISSET(ops, 'q'));
-
-    errno = 0;
-    secs = (time_t)strtoul(argv[1], &endptr, 10);
-    if (errno != 0) {
-	zwarnnam(nam, "%s: %e", argv[1], errno);
-	return 1;
-    } else if (*endptr != '\0') {
-	zwarnnam(nam, "%s: invalid decimal number", argv[1]);
-	return 1;
     }
 
-    t = localtime(&secs);
-    if (!t) {
-	zwarnnam(nam, "%s: unable to convert to time", argv[1]);
-	return 1;
+    if (!argv[1]) {
+	zgettime(&ts);
+	tm = localtime(&ts.tv_sec);
+    } else {
+	errno = 0;
+
+	ts.tv_sec = (time_t)strtoul(argv[1], &endptr, 10);
+	if (errno != 0) {
+	    zwarnnam(nam, "%s: %e", argv[1], errno);
+	    return 1;
+	} else if (*argv[1] == '\0' || *endptr != '\0') {
+	    zwarnnam(nam, "%s: invalid decimal number", argv[1]);
+	    return 1;
+	}
+
+	tm = localtime(&ts.tv_sec);
+	if (!tm) {
+	    zwarnnam(nam, "%s: unable to convert to time", argv[1]);
+	    return 1;
+	}
+
+	ts.tv_nsec = 0L;
+	if (argv[2]) {
+	    ts.tv_nsec = (long)zstrtol(argv[2], &endptr, 10);
+	    if (errno != 0) {
+		zwarnnam(nam, "%s: %e", argv[2], errno);
+		return 1;
+	    } else if (*argv[2] == '\0' || *endptr != '\0') {
+		zwarnnam(nam, "%s: invalid decimal number", argv[2]);
+		return 1;
+	    } else if (ts.tv_nsec < 0) {
+		zwarnnam(nam, "%s: invalid nanosecond value", argv[2]);
+		return 1;
+	    }
+	}
     }
+
     bufsize = strlen(argv[0]) * 8;
     buffer = zalloc(bufsize);
 
     len = 0;
     for (x=0; x < 4; x++) {
-        if ((len = ztrftime(buffer, bufsize, argv[0], t, 0L)) >= 0 || x==3)
+        if ((len = ztrftime(buffer, bufsize, argv[0], tm, ts.tv_nsec)) >= 0 ||
+	    x==3)
 	    break;
 	buffer = zrealloc(buffer, bufsize *= 2);
     }
@@ -207,7 +235,7 @@ getcurrenttime(UNUSED(Param pm))
 }
 
 static struct builtin bintab[] = {
-    BUILTIN("strftime",    0, bin_strftime,    2,   2, 0, "qrs:", NULL),
+    BUILTIN("strftime",    0, bin_strftime,    1,   3, 0, "qrs:", NULL),
 };
 
 static const struct gsu_integer epochseconds_gsu =

Test/V09datetime.ztst

@@ -82,3 +82,32 @@
 # The result can be '%@' (Linux), '@' (BSDs) or an error (Cygwin).
   [[ $(strftime '%@' 0 2> /dev/null) == (%|)@ || $? != 0 ]]
 0:bad format specifier
+
+# This test may fail at 23:59:59.xxx on New Year's Eve :/
+  [[ "$( strftime '%Y' )" == "$( strftime '%Y' "$EPOCHSECONDS" )" ]]
+0:epochtime optional
+
+  strftime '%Y-%m-%d %H:%M:%S.%3.' 1012615322
+  strftime '%Y-%m-%d %H:%M:%S.%3.' 1012615322 0
+  strftime '%Y-%m-%d %H:%M:%S.%3.' 1012615322 2
+  strftime '%Y-%m-%d %H:%M:%S.%3.' 1012615322 $(( 222 * (10 ** 9) ))
+0:optional nanoseconds
+>2002-02-02 02:02:02.000
+>2002-02-02 02:02:02.000
+>2002-02-02 02:02:02.000
+>2002-02-02 02:02:02.222
+
+  strftime '%Y' '' 2> /dev/null
+1:empty epochtime not allowed
+
+  strftime '%Y' 1012615322 '' 2> /dev/null
+1:empty nanoseconds not allowed
+
+  strftime '%N' 1012615322 ${(l<64><9>):-} 2> /dev/null
+1:overflowed nanoseconds not allowed
+
+  strftime '%N' 1012615322 -1 2> /dev/null
+1:negative nanoseconds not allowed
+
+  strftime -r '%Y' 2> /dev/null
+1:-r timestring not optional