From dc70eb797610565650ed2b8d91b1ec74d0ca1197 Mon Sep 17 00:00:00 2001
From: sin <sin@2f30.org>
Date: Tue, 20 Jan 2015 16:50:37 +0000
Subject: [PATCH] ls: Implement -c and update manpage

Update usage + README as well.  Apparently some of the options (
-H and -L) had already been implemented but not reflected in the
program usage line.
---
 README |  2 +-
 ls.1   | 87 ++++++++++++++++++++++++++++------------------------------
 ls.c   | 16 +++++++----
 3 files changed, 53 insertions(+), 52 deletions(-)

diff --git a/README b/README
index e51cb5a..ff90332 100644
--- a/README
+++ b/README
@@ -40,7 +40,7 @@ The following tools are implemented ('*' == finished, '#' == UTF-8 support,
 =  ln              yes                             none
 =* logger          yes                             none
 =  logname         yes                             none
-=  ls              no                              -C, -H, -L, -R, -c, -q, -u
+=  ls              no                              -C, -R, -q, -u
    md5sum          non-posix                       none
 =  mkdir           yes                             none
 =  mkfifo          yes                             none
diff --git a/ls.1 b/ls.1
index 792b07b..0bb6269 100644
--- a/ls.1
+++ b/ls.1
@@ -1,49 +1,46 @@
-.TH LS 1 sbase\-VERSION
-.SH NAME
-ls \- list directory contents
-.SH SYNOPSIS
-.B ls
-.RB [ \-adFHhiLlrtU ]
-.RI [ file ...]
-.SH DESCRIPTION
-.B ls
+.Dd January 20, 2015
+.Dt LS 1 sbase\-VERSION
+.Sh NAME
+.Nm ls
+.Nd list directory contents
+.Sh SYNOPSIS
+.Nm ls
+.Op Fl 1acdFHhiLlrtU
+.Op Ar file ...
+.Sh DESCRIPTION
+.Nm
 lists each given file, and the contents of each given directory.  If no files
 are given the current directory is listed.
-.SH OPTIONS
-.TP
-.B \-a
-shows hidden files (those beginning with '.').
-.TP
-.B \-d
-lists directories themselves, not their contents.
-.TP
-.B \-F
-append a file type indicator to files.
-.TP
-.B \-H
-list information about the targets of symbolic links specified on the command
+.Sh OPTIONS
+.Bl -tag -width Ds
+.It Fl a
+Show hidden files (those beginning with '.').
+.It Fl c
+Use time file's status was last changed instead of last
+modification time for sorting or printing.
+.It Fl d
+List directories themselves, not their contents.
+.It Fl F
+Append a file type indicator to files.
+.It Fl H
+List information about the targets of symbolic links specified on the command
 line instead of the links themselves.
-.TP
-.B \-h
-show filesizes in human\-readable format.
-.TP
-.B \-i
-print the index number of each file.
-.TP
-.B \-L
-list information about the targets of symbolic links instead of the links
+.It Fl h
+Show filesizes in human\-readable format.
+.It Fl i
+Print the index number of each file.
+.It Fl L
+List information about the targets of symbolic links instead of the links
 themselves.
-.B \-l
-lists detailed information about each file, including their type, permissions,
-links, owner, group, size, and modification time.
-.TP
-.B \-r
-reverses the sort order.
-.TP
-.B \-t
-sorts files by modification time instead of by name.
-.TP
-.B \-U
-keeps the list unsorted.
-.SH SEE ALSO
-.IR stat (2)
+.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 r
+Reverse the sort order.
+.It Fl t
+Sort files by last file status/modification time instead of by name.
+.It Fl U
+Keep the list unsorted.
+.El
+.Sh SEE ALSO
+.Xr stat 2
diff --git a/ls.c b/ls.c
index 8862b87..4ac0da2 100644
--- a/ls.c
+++ b/ls.c
@@ -18,7 +18,7 @@ typedef struct {
 	uid_t uid;
 	gid_t gid;
 	off_t size;
-	time_t mtime;
+	time_t t;
 	ino_t ino;
 } Entry;
 
@@ -29,6 +29,7 @@ static void mkent(Entry *, char *, int, int);
 static void output(Entry *);
 
 static int aflag = 0;
+static int cflag = 0;
 static int dflag = 0;
 static int Fflag = 0;
 static int Hflag = 0;
@@ -45,7 +46,7 @@ static int many;
 static void
 usage(void)
 {
-	eprintf("usage: %s [-1adFhilrtU] [FILE...]\n", argv0);
+	eprintf("usage: %s [-1acdFHhiLlrtU] [file ...]\n", argv0);
 }
 
 int
@@ -61,6 +62,9 @@ main(int argc, char *argv[])
 	case 'a':
 		aflag = 1;
 		break;
+	case 'c':
+		cflag = 1;
+		break;
 	case 'd':
 		dflag = 1;
 		break;
@@ -116,7 +120,7 @@ entcmp(const void *va, const void *vb)
 	const Entry *a = va, *b = vb;
 
 	if (tflag)
-		return b->mtime - a->mtime;
+		return b->t - a->t;
 	else
 		return strcmp(a->name, b->name);
 }
@@ -196,7 +200,7 @@ 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->mtime  = st.st_mtime;
+	ent->t      = cflag ? st.st_ctime : st.st_mtime;
 	ent->ino    = st.st_ino;
 	if (S_ISLNK(ent->mode))
 		ent->tmode = stat(path, &st) == 0 ? st.st_mode : 0;
@@ -284,12 +288,12 @@ output(Entry *ent)
 	else
 		snprintf(grname, sizeof(grname), "%d", ent->gid);
 
-	if (time(NULL) > ent->mtime + (180*24*60*60)) /* 6 months ago? */
+	if (time(NULL) > ent->t + (180*24*60*60)) /* 6 months ago? */
 		fmt = "%b %d  %Y";
 	else
 		fmt = "%b %d %H:%M";
 
-	strftime(buf, sizeof buf, fmt, localtime(&ent->mtime));
+	strftime(buf, sizeof buf, fmt, localtime(&ent->t));
 	printf("%s %4ld %-8.8s %-8.8s ", mode, (long)ent->nlink, pwname, grname);
 	if (hflag)
 		printf("%10s ", humansize((unsigned long)ent->size));