From 76218e5eb0c081ac8718fd1a1cfc28da16595a71 Mon Sep 17 00:00:00 2001
From: Tai Chi Minh Ralph Eastwood <tcmreastwood@gmail.com>
Date: Sun, 15 Feb 2015 10:23:21 +0000
Subject: [PATCH 3/4] ls: add implementation of -q and -u flags

---
 ls.1 |  5 +++++
 ls.c | 51 +++++++++++++++++++++++++++++++++++++++++++++------
 2 files changed, 50 insertions(+), 6 deletions(-)

diff --git a/ls.1 b/ls.1
index ad90b37..2aa37b2 100644
--- a/ls.1
+++ b/ls.1
@@ -38,6 +38,8 @@ themselves.
 .It Fl l
 List detailed information about each file, including their type, permissions,
 links, owner, group, size, and last file status/modification time.
+.It Fl q
+When printing file names, replace all non-printable characters with 'q'.
 .It Fl R
 Traverse directories recursively.
 .It Fl r
@@ -46,6 +48,9 @@ Reverse the sort order.
 Sort files by last file status/modification time instead of by name.
 .It Fl U
 Keep the list unsorted.
+.It Fl u
+Use time file was last access instead of last modification time for sorting
+or printing.
 .El
 .Sh SEE ALSO
 .Xr stat 2
diff --git a/ls.c b/ls.c
index eec5145..75cb418 100644
--- a/ls.c
+++ b/ls.c
@@ -12,6 +12,7 @@
 #include <unistd.h>
 
 #include "util.h"
+#include "utf.h"
 
 typedef struct {
 	char *name;
@@ -46,6 +47,8 @@ static int tflag = 0;
 static int Uflag = 0;
 static int Cflag = 0;
 static int Rflag = 0;
+static int qflag = 0;
+static int uflag = 0;
 static int many;
 static int first = 1;
 static struct winsize ws;
@@ -53,7 +56,7 @@ static struct winsize ws;
 static void
 usage(void)
 {
-	eprintf("usage: %s [-1aCcdFHhiLlRrtU] [file ...]\n", argv0);
+	eprintf("usage: %s [-1aCcdFHhiLlqRrtUu] [file ...]\n", argv0);
 }
 
 int
@@ -74,6 +77,7 @@ main(int argc, char *argv[])
 		break;
 	case 'c':
 		cflag = 1;
+		uflag = 0;
 		break;
 	case 'd':
 		dflag = 1;
@@ -112,6 +116,13 @@ main(int argc, char *argv[])
 	case 'R':
 		Rflag = 1;
 		break;
+	case 'q':
+		qflag = 1;
+		break;
+	case 'u':
+		uflag = 1;
+		cflag = 0;
+		break;
 	default:
 		usage();
 	} ARGEND;
@@ -276,7 +287,12 @@ mkent(Entry *ent, char *path, int dostat, int follow)
 	ent->uid    = st.st_uid;
 	ent->gid    = st.st_gid;
 	ent->size   = st.st_size;
-	ent->t      = cflag ? st.st_ctime : st.st_mtime;
+	if (cflag)
+		ent->t = st.st_ctime;
+	else if (uflag)
+		ent->t = st.st_atime;
+	else
+		ent->t = st.st_mtime;
 	ent->ino    = st.st_ino;
 	if (S_ISLNK(ent->mode))
 		ent->tmode = stat(path, &st) == 0 ? st.st_mode : 0;
@@ -314,12 +330,32 @@ output(Entry *ent, FILE *f)
 	struct passwd *pw;
 	char pwname[_SC_LOGIN_NAME_MAX];
 	char grname[_SC_LOGIN_NAME_MAX];
+	char *name = ent->name, *p, *n;
+	Rune r;
 
 	first = 0;
+
+	if (qflag) {
+		n = name = emalloc(utflen(ent->name) + 1);
+		strcpy(name, (p = ent->name));
+		while (*p) {
+			len = chartorune(&r, p);
+			if (isprintrune(r)) {
+				while (len) {
+					*n++ = *p++;
+					--len;
+				}
+			} else {
+				*n++ = '?';
+				p += len;
+			}
+		}
+		*n++ = '\0';
+	}
 	if (iflag)
 		fprintf(f, "%lu ", (unsigned long)ent->ino);
 	if (!lflag) {
-		fprintf(f, "%s%s\n", ent->name, indicator(ent->mode));
+		fprintf(f, "%s%s\n", name, indicator(ent->mode));
 		return;
 	}
 	if (S_ISREG(ent->mode))
@@ -376,14 +412,17 @@ output(Entry *ent, FILE *f)
 		fprintf(f, "%10s ", humansize((unsigned long)ent->size));
 	else
 		fprintf(f, "%10lu ", (unsigned long)ent->size);
-	fprintf(f, "%s %s%s", buf, ent->name, indicator(ent->mode));
+	fprintf(f, "%s %s%s", buf, name, indicator(ent->mode));
 	if (S_ISLNK(ent->mode)) {
-		if ((len = readlink(ent->name, buf, sizeof buf - 1)) < 0)
-			eprintf("readlink %s:", ent->name);
+		if ((len = readlink(name, buf, sizeof buf - 1)) < 0)
+			eprintf("readlink %s:", name);
 		buf[len] = '\0';
 		fprintf(f, " -> %s%s", buf, indicator(ent->tmode));
 	}
 	fputc('\n', f);
+
+	if (name != ent->name)
+		free(name);
 }
 
 static void columns(char *buf, size_t sz, int cnt)
-- 
2.3.0