add a do_realpath() implementation replacing the use of the external

libc function realpath(3) which may not be available on the target
system; compile the realpath builtin unconditionally

looks fine to me, but review is appreciated; this is (very) lightly
based upon MirBSD libc’s realpath(3) and pdksh’s get_phys_path()
This commit is contained in:
tg 2009-08-30 13:22:39 +00:00
parent 75a7eb63e1
commit 31e02e59f7
3 changed files with 151 additions and 35 deletions

View File

@ -1,5 +1,5 @@
#!/bin/sh
srcversion='$MirOS: src/bin/mksh/Build.sh,v 1.422 2009/08/28 17:37:47 tg Exp $'
srcversion='$MirOS: src/bin/mksh/Build.sh,v 1.423 2009/08/30 13:22:37 tg Exp $'
#-
# Copyright (c) 2003, 2004, 2005, 2006, 2007, 2008, 2009
# Thorsten Glaser <tg@mirbsd.org>
@ -919,7 +919,6 @@ if ac_ifcpp 'ifdef MKSH_SMALL' isset_MKSH_SMALL '' \
fi
: ${HAVE_MKNOD=0}
: ${HAVE_REALPATH=0}
: ${HAVE_REVOKE=0}
: ${HAVE_PERSISTENT_HISTORY=0}
check_categories=$check_categories,smksh
@ -1168,23 +1167,6 @@ ac_test nice <<-'EOF'
int main(void) { return (nice(4)); }
EOF
ac_test realpath <<-'EOF'
#if HAVE_SYS_PARAM_H
#include <sys/param.h>
#endif
#include <stdlib.h>
#include <unistd.h>
#ifndef PATH_MAX
#define PATH_MAX 1024
#endif
char *res, dst[PATH_MAX];
const char src[] = ".";
int main(void) {
res = realpath(src, dst);
return (res == NULL ? 1 : 0);
}
EOF
ac_test revoke <<-'EOF'
#include <sys/types.h>
#if HAVE_LIBUTIL_H

162
funcs.c
View File

@ -25,7 +25,7 @@
#include "sh.h"
__RCSID("$MirOS: src/bin/mksh/funcs.c,v 1.125 2009/08/28 21:51:51 tg Exp $");
__RCSID("$MirOS: src/bin/mksh/funcs.c,v 1.126 2009/08/30 13:22:38 tg Exp $");
#if HAVE_KILLPG
/*
@ -102,9 +102,7 @@ const struct builtin mkshbuiltins[] = {
#if HAVE_MKNOD
{"mknod", c_mknod},
#endif
#if HAVE_REALPATH
{"realpath", c_realpath},
#endif
{"rename", c_rename},
{NULL, (int (*)(const char **))NULL}
};
@ -173,6 +171,146 @@ static void ptest_error(Test_env *, int, const char *);
static char *kill_fmt_entry(const void *, int, char *, int);
static void p_time(struct shf *, bool, long, int, int,
const char *, const char *) __attribute__((nonnull (6, 7)));
static char *do_realpath(const char *);
static char *
do_realpath(const char *upath)
{
char *xp, *ip, *tp, *ipath, *ldest = NULL;
XString xs;
ptrdiff_t pos;
size_t len;
int symlinks = 32; /* max. recursion depth */
int llen;
struct stat sb;
if (upath[0] == '/') {
/* upath is an absolute pathname */
strdupx(ipath, upath, ATEMP);
} else {
/* upath is a relative pathname, prepend cwd */
if ((tp = ksh_get_wd(NULL)) == NULL || tp[0] != '/')
return (NULL);
ipath = shf_smprintf("%s/%s", tp, upath);
afree(tp, ATEMP);
}
Xinit(xs, xp, strlen(ip = ipath) + 1, ATEMP);
while (*ip) {
/* skip slashes in input */
while (*ip == '/')
++ip;
if (!*ip)
break;
/* get next pathname component from input */
tp = ip;
while (*ip && *ip != '/')
++ip;
len = ip - tp;
/* check input for "." and ".." */
if (tp[0] == '.') {
if (len == 1)
/* just continue with the next one */
continue;
else if (len == 2 && tp[1] == '.') {
/* strip off last pathname component */
while (xp > Xstring(xs, xp))
if (*--xp == '/')
break;
/* then continue with the next one */
continue;
}
}
/* store output position away, then append slash to output */
pos = Xsavepos(xs, xp);
Xcheck(xs, xp);
Xput(xs, xp, '/');
/* append next pathname component to output */
XcheckN(xs, xp, len + 1);
memcpy(xp, tp, len);
xp += len;
*xp = '\0';
/* lstat the current output, see if it's a symlink */
if (lstat(Xstring(xs, xp), &sb)) {
/* lstat failed */
if (errno == ENOENT) {
/* because the pathname does not exist */
while (*ip == '/')
/* skip any trailing slashes */
++ip;
/* no more components left? */
if (!*ip)
/* we can still return successfully */
break;
/* more components left? fall through */
}
/* not ENOENT or not at the end of ipath */
goto notfound;
}
/* check if we encountered a symlink? */
if (S_ISLNK(sb.st_mode)) {
/* reached maximum recursion depth? */
if (!symlinks--) {
/* yep, prevent infinite loops */
errno = ELOOP;
goto notfound;
}
/* get symlink(7) target */
if (!ldest)
ldest = alloc(PATH_MAX + 1, ATEMP);
if ((llen = readlink(Xstring(xs, xp), ldest,
PATH_MAX)) < 0)
/* oops... */
goto notfound;
ldest[llen] = '\0';
/*
* restart if symlink target is an absolute path,
* otherwise continue with currently resolved prefix
*/
xp = (ldest[0] == '/') ? Xstring(xs, xp) :
Xrestpos(xs, xp, pos);
tp = shf_smprintf("%s/%s", ldest, ip);
afree(ipath, ATEMP);
ip = ipath = tp;
}
/* otherwise (no symlink) merely go on */
}
/*
* either found the target and successfully resolved it,
* or found its parent directory and may create it
*/
if (Xlength(xs, xp) == 0)
/*
* if the resolved pathname is "", make it "/",
* otherwise do not add a trailing slash
*/
Xput(xs, xp, '/');
Xput(xs, xp, '\0');
if (ldest != NULL)
afree(ldest, ATEMP);
afree(ipath, ATEMP);
return (Xclose(xs, xp));
notfound:
llen = errno; /* save; free(3) might trash it */
if (ldest != NULL)
afree(ldest, ATEMP);
afree(ipath, ATEMP);
Xfree(xs, xp);
errno = llen;
return (NULL);
}
int
c_cd(const char **wp)
@ -3124,11 +3262,11 @@ c_rename(const char **wp)
return (rv);
}
#if HAVE_REALPATH
int
c_realpath(const char **wp)
{
int rv = 1;
char *buf;
if (wp != NULL && wp[0] != NULL && wp[1] != NULL) {
if (strcmp(wp[1], "--")) {
@ -3146,17 +3284,15 @@ c_realpath(const char **wp)
if (rv)
bi_errorf(T_synerr);
else {
char *buf;
if (realpath(*wp, (buf = alloc(PATH_MAX, ATEMP))) == NULL) {
rv = errno;
bi_errorf("%s: %s", *wp, strerror(rv));
} else
shprintf("%s\n", buf);
else if ((buf = do_realpath(*wp)) == NULL) {
rv = errno;
bi_errorf("%s: %s", *wp, strerror(rv));
if ((unsigned int)rv > 255)
rv = 255;
} else {
shprintf("%s\n", buf);
afree(buf, ATEMP);
}
return (rv);
}
#endif

4
sh.h
View File

@ -134,7 +134,7 @@
#endif
#ifdef EXTERN
__RCSID("$MirOS: src/bin/mksh/sh.h,v 1.334 2009/08/28 22:46:21 tg Exp $");
__RCSID("$MirOS: src/bin/mksh/sh.h,v 1.335 2009/08/30 13:22:39 tg Exp $");
#endif
#define MKSH_VERSION "R39 2009/08/28"
@ -1434,9 +1434,7 @@ int c_test(const char **);
#if HAVE_MKNOD
int c_mknod(const char **);
#endif
#if HAVE_REALPATH
int c_realpath(const char **);
#endif
int c_rename(const char **);
/* histrap.c */
void init_histvec(void);