ls: Handle symlinks to directories properly

Also, implement the -H and -L options.
This commit is contained in:
Michael Forney 2014-12-08 01:33:52 +00:00 committed by sin
parent c4014b730e
commit 46ea55a258
2 changed files with 28 additions and 13 deletions

9
ls.1
View File

@ -3,7 +3,7 @@
ls \- list directory contents
.SH SYNOPSIS
.B ls
.RB [ \-adFiltU ]
.RB [ \-adFHhiLlrtU ]
.RI [ file ...]
.SH DESCRIPTION
.B ls
@ -20,12 +20,19 @@ lists directories themselves, not their contents.
.B \-F
append a file type indicator to files.
.TP
.B \-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
themselves.
.B \-l
lists detailed information about each file, including their type, permissions,
links, owner, group, size, and modification time.

32
ls.c
View File

@ -14,7 +14,7 @@
typedef struct {
char *name;
mode_t mode;
mode_t mode, tmode;
nlink_t nlink;
uid_t uid;
gid_t gid;
@ -26,14 +26,16 @@ typedef struct {
static int entcmp(const void *, const void *);
static void ls(Entry *);
static void lsdir(const char *);
static void mkent(Entry *, char *, int);
static void mkent(Entry *, char *, int, int);
static void output(Entry *);
static int aflag = 0;
static int dflag = 0;
static int Fflag = 0;
static int Hflag = 0;
static int hflag = 0;
static int iflag = 0;
static int Lflag = 0;
static int lflag = 0;
static int rflag = 0;
static int tflag = 0;
@ -66,12 +68,18 @@ main(int argc, char *argv[])
case 'F':
Fflag = 1;
break;
case 'H':
Hflag = 1;
break;
case 'h':
hflag = 1;
break;
case 'i':
iflag = 1;
break;
case 'L':
Lflag = 1;
break;
case 'l':
lflag = 1;
break;
@ -95,7 +103,7 @@ main(int argc, char *argv[])
ents = emalloc(argc * sizeof(*ents));
for (i = 0; i < argc; i++)
mkent(&ents[i], argv[i], 1);
mkent(&ents[i], argv[i], 1, Hflag || Lflag);
qsort(ents, argc, sizeof *ents, entcmp);
for (i = 0; i < argc; i++)
ls(&ents[rflag ? argc-i-1 : i]);
@ -117,7 +125,7 @@ entcmp(const void *va, const void *vb)
static void
ls(Entry *ent)
{
if (S_ISDIR(ent->mode) && !dflag) {
if ((S_ISDIR(ent->mode) || (S_ISLNK(ent->mode) && S_ISDIR(ent->tmode) && !Fflag && !lflag)) && !dflag) {
lsdir(ent->name);
} else {
output(ent);
@ -151,13 +159,13 @@ lsdir(const char *path)
if (d->d_name[0] == '.' && !aflag)
continue;
if (Uflag){
mkent(&ent, d->d_name, Fflag || lflag || iflag);
mkent(&ent, d->d_name, Fflag || lflag || iflag, Lflag);
output(&ent);
} else {
ents = erealloc(ents, ++n * sizeof *ents);
p = emalloc((sz = strlen(d->d_name)+1));
memcpy(p, d->d_name, sz);
mkent(&ents[n-1], p, tflag || Fflag || lflag || iflag);
mkent(&ents[n-1], p, tflag || Fflag || lflag || iflag, Lflag);
}
}
closedir(dp);
@ -175,15 +183,15 @@ lsdir(const char *path)
}
static void
mkent(Entry *ent, char *path, int dostat)
mkent(Entry *ent, char *path, int dostat, int follow)
{
struct stat st;
ent->name = path;
if (!dostat)
return;
if (lstat(path, &st) < 0)
eprintf("lstat %s:", path);
if ((follow ? stat : lstat)(path, &st) < 0)
eprintf("%s %s:", follow ? "stat" : "lstat", path);
ent->mode = st.st_mode;
ent->nlink = st.st_nlink;
ent->uid = st.st_uid;
@ -191,6 +199,8 @@ mkent(Entry *ent, char *path, int dostat)
ent->size = st.st_size;
ent->mtime = st.st_mtime;
ent->ino = st.st_ino;
if (S_ISLNK(ent->mode))
ent->tmode = stat(path, &st) == 0 ? st.st_mode : 0;
}
static char *
@ -225,7 +235,6 @@ output(Entry *ent)
struct passwd *pw;
char pwname[_SC_LOGIN_NAME_MAX];
char grname[_SC_LOGIN_NAME_MAX];
Entry entlnk;
if (iflag)
printf("%lu ", (unsigned long)ent->ino);
@ -294,8 +303,7 @@ output(Entry *ent)
if ((len = readlink(ent->name, buf, sizeof buf)) < 0)
eprintf("readlink %s:", ent->name);
buf[len] = '\0';
mkent(&entlnk, buf, Fflag);
printf(" -> %s%s", buf, indicator(entlnk.mode));
printf(" -> %s%s", buf, indicator(ent->tmode));
}
putchar('\n');
}