Fix ls -l alignement with new locales

Latest update of locales introduced abbreviated month that follows the regionale
rules meaning that they can be of variable length instead of being arbitrary
truncated to top 3 characters.

To fix alignement, ls now computes the visible length of the abbreviated month,
pads the shorter month with spaces in order to make sure everything is properly
aligned

Reviewed by:	ache, ed, jilles
Differential Revision:	https://reviews.freebsd.org/D4239

1 files changed, 95 insertions, 1 deletions

diff --git a/bin/ls/print.c b/bin/ls/print.c
index 70f53ba70663..7fe73a63bf43 100644
--- a/bin/ls/print.c
+++ b/bin/ls/print.c
@@ -47,12 +47,14 @@ __FBSDID("$FreeBSD$");
 #include <fts.h>
 #include <langinfo.h>
 #include <libutil.h>
+#include <limits.h>
 #include <stdio.h>
 #include <stdint.h>
 #include <stdlib.h>
 #include <string.h>
 #include <time.h>
 #include <unistd.h>
+#include <wchar.h>
 #ifdef COLORLS
 #include <ctype.h>
 #include <termcap.h>
@@ -105,6 +107,9 @@ static struct {
 } colors[C_NUMCOLORS];
 #endif
 
+static size_t padding_for_month[12];
+static size_t month_max_size = 0;
+
 void
 printscol(const DISPLAY *dp)
 {
@@ -138,6 +143,70 @@ printname(const char *field, const char *name)
 	return rc;
 }
 
+static const char *
+get_abmon(int mon)
+{
+
+	switch (mon) {
+	case 0: return (nl_langinfo(ABMON_1));
+	case 1: return (nl_langinfo(ABMON_2));
+	case 2: return (nl_langinfo(ABMON_3));
+	case 3: return (nl_langinfo(ABMON_4));
+	case 4: return (nl_langinfo(ABMON_5));
+	case 5: return (nl_langinfo(ABMON_6));
+	case 6: return (nl_langinfo(ABMON_7));
+	case 7: return (nl_langinfo(ABMON_8));
+	case 8: return (nl_langinfo(ABMON_9));
+	case 9: return (nl_langinfo(ABMON_10));
+	case 10: return (nl_langinfo(ABMON_11));
+	case 11: return (nl_langinfo(ABMON_12));
+	}
+
+	/* should never happen */
+	abort();
+}
+
+static size_t
+mbswidth(const char *month)
+{
+	wchar_t wc;
+	size_t width, donelen, clen, w;
+
+	width = donelen = 0;
+	while ((clen = mbrtowc(&wc, month + donelen, MB_LEN_MAX, NULL)) != 0) {
+		if (clen == (size_t)-1 || clen == (size_t)-2)
+			return (-1);
+		donelen += clen;
+		if ((w = wcwidth(wc)) == (size_t)-1)
+			return (-1);
+		width += w;
+	}
+
+	return (width);
+}
+
+static void
+compute_abbreviated_month_size(void)
+{
+	int i;
+	size_t width;
+	size_t months_width[12];
+
+	for (i = 0; i < 12; i++) {
+		width = mbswidth(get_abmon(i));
+		if (width == (size_t)-1) {
+			month_max_size = -1;
+			return;
+		}
+		months_width[i] = width;
+		if (width > month_max_size)
+			month_max_size = width;
+	}
+
+	for (i = 0; i < 12; i++)
+		padding_for_month[i] = month_max_size - months_width[i];
+}
+
 /*
  * print name in current style
  */
@@ -425,6 +494,31 @@ printdev(size_t width, dev_t dev)
 	xo_emit("{:device/%#*jx} ", (u_int)width, (uintmax_t)dev);
 }
 
+static size_t
+ls_strftime(char *str, size_t len, const char *fmt, const struct tm *tm)
+{
+	char *posb, nfmt[BUFSIZ];
+	const char *format = fmt;
+	size_t ret;
+
+	if ((posb = strstr(fmt, "%b")) != NULL) {
+		if (month_max_size == 0) {
+			compute_abbreviated_month_size();
+		}
+		if (month_max_size > 0) {
+			snprintf(nfmt, sizeof(nfmt),  "%.*s%s%*s%s",
+			    (int)(posb - fmt), fmt,
+			    get_abmon(tm->tm_mon),
+			    (int)padding_for_month[tm->tm_mon],
+			    "",
+			    posb + 2);
+			format = nfmt;
+		}
+	}
+	ret = strftime(str, len, format, tm);
+	return (ret);
+}
+
 static void
 printtime(const char *field, time_t ftime)
 {
@@ -451,7 +545,7 @@ printtime(const char *field, time_t ftime)
 	else
 		/* mmm dd  yyyy || dd mmm  yyyy */
 		format = d_first ? "%e %b  %Y" : "%b %e  %Y";
-	strftime(longstring, sizeof(longstring), format, localtime(&ftime));
+	ls_strftime(longstring, sizeof(longstring), format, localtime(&ftime));
 
 	snprintf(fmt, sizeof(fmt), "{d:%s/%%hs} ", field);
 	xo_attr("value", "%ld", (long) ftime);