/*-------------------------------------------------------------
The namei program
By: Roger S. Southwick
May 2, 1990
Modifications by Steve Tell March 28, 1991
usage: namei pathname [pathname ... ]
This program reads it's arguments as pathnames to any type
of Unix file (symlinks, files, directories, and so forth).
The program then follows each pathname until a terminal
point is found (a file, directory, char device, etc).
If it finds a symbolic link, we show the link, and start
following it, indenting the output to show the context.
This program is useful for finding a "too many levels of
symbolic links" problems.
For each line output, the program puts a file type first:
f: = the pathname we are currently trying to resolve
d = directory
D = directory that is a mount point
l = symbolic link (both the link and it's contents are output)
s = socket
b = block device
c = character device
p = FIFO (named pipe)
- = regular file
? = an error of some kind
The program prints an informative messages when we exceed
the maximum number of symbolic links this system can have.
The program exits with a 1 status ONLY if it finds it cannot
chdir to /, or if it encounters an unknown file type.
1999-02-22 Arkadiusz Mi¶kiewicz <misiek@pld.ORG.PL>
- added Native Language Support
2006-12-15 Karel Zak <kzak@redhat.com>
- fixed logic; don't follow the path if a component is not directory
- fixed infinite loop of symbolic links; stack size is very limited
2007-09-10 Li Zefan <lizf@cn.fujitsu.com>
- added to identify FIFO
-------------------------------------------------------------*/
#include <stdio.h>
#include <unistd.h>
#include <string.h>
#include <strings.h>
#include <stdlib.h>
#include <errno.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/param.h>
#include "nls.h"
#define ERR strerror(errno),errno
int symcount;
int mflag = 0;
int xflag = 0;
#ifndef MAXSYMLINKS
#define MAXSYMLINKS 256
#endif
#ifndef PATH_MAX
#define PATH_MAX 4096
#endif
static char *pperm(unsigned short);
static void namei(char *, int, mode_t *);
static void usage(void);
int
main(int argc, char **argv) {
extern int optind;
int c;
#ifdef HAVE_GET_CURRENT_DIR_NAME
char *curdir;
#else
char curdir[PATH_MAX];
#endif
setlocale(LC_ALL, "");
bindtextdomain(PACKAGE, LOCALEDIR);
textdomain(PACKAGE);
if(argc < 2)
usage();
while((c = getopt(argc, argv, "mx")) != -1){
switch(c){
case 'm':
mflag = !mflag;
break;
case 'x':
xflag = !xflag;
break;
case '?':
default:
usage();
}
}
#ifdef HAVE_GET_CURRENT_DIR_NAME
if (!(curdir = get_current_dir_name()))
#else
if(getcwd(curdir, sizeof(curdir)) == NULL)
#endif
{
(void)fprintf(stderr,
_("namei: unable to get current directory - %s\n"),
curdir);
exit(1);
}
for(; optind < argc; optind++){
mode_t lastmode = 0;
(void)printf("f: %s\n", argv[optind]);
symcount = 1;
namei(argv[optind], 0, &lastmode);
if(chdir(curdir) == -1){
(void)fprintf(stderr,
_("namei: unable to chdir to %s - %s (%d)\n"),
curdir, ERR);
exit(1);
}
}
return 0;
}
static void
usage(void) {
(void)fprintf(stderr,_("usage: namei [-mx] pathname [pathname ...]\n"));
exit(1);
}
#ifndef NODEV
#define NODEV (dev_t)(-1)
#endif
static void
namei(char *file, int lev, mode_t *lastmode) {
char *cp;
char buf[BUFSIZ], sym[BUFSIZ];
struct stat stb;
int i;
dev_t lastdev = NODEV;
/*
* See if the file has a leading /, and if so cd to root
*/
if(file && *file == '/'){
while(*file == '/')
file++;
if(chdir("/") == -1){
(void)fprintf(stderr,_("namei: could not chdir to root!\n"));
exit(1);
}
for(i = 0; i < lev; i++)
(void)printf(" ");
if(stat("/", &stb) == -1){
(void)fprintf(stderr, _("namei: could not stat root!\n"));
exit(1);
}
lastdev = stb.st_dev;
if(mflag)
(void)printf(" d%s /\n", pperm(stb.st_mode));
else
(void)printf(" d /\n");
}
for(; file && *file;){
if (strlen(file) >= BUFSIZ) {
fprintf(stderr,_("namei: buf overflow\n"));
return;
}
/*
* Copy up to the next / (or nil) into buf
*/
for(cp = buf; *file != '\0' && *file != '/'; cp++, file++)
*cp = *file;
while(*file == '/') /* eat extra /'s */
file++;
*cp = '\0';
if(buf[0] == '\0'){
/*
* Buf is empty, so therefore we are done
* with this level of file
*/
return;
}
for(i = 0; i < lev; i++)
(void)printf(" ");
/*
* We cannot walk on *path* if a previous element, in the path wasn't
* directory, because there could be a component with same name. Try:
*
* $ touch a b
* $ namei a/b <-- "a" is not directory so namei shouldn't
* check for "b"
*/
if (*lastmode && S_ISDIR(*lastmode)==0 && S_ISLNK(*lastmode)==0){
(void)printf(" ? %s - %s (%d)\n", buf, strerror(ENOENT), ENOENT);
return;
}
/*
* See what type of critter this file is
*/
if(lstat(buf, &stb) == -1){
(void)printf(" ? %s - %s (%d)\n", buf, ERR);
return;
}
*lastmode = stb.st_mode;
switch(stb.st_mode & S_IFMT){
case S_IFDIR:
/*
* File is a directory, chdir to it
*/
if(chdir(buf) == -1){
(void)printf(_(" ? could not chdir into %s - %s (%d)\n"), buf, ERR );
return;
}
if(xflag && lastdev != stb.st_dev && lastdev != NODEV){
/* Across mnt point */
if(mflag)
(void)printf(" D%s %s\n", pperm(stb.st_mode), buf);
else
(void)printf(" D %s\n", buf);
}
else {
if(mflag)
(void)printf(" d%s %s\n", pperm(stb.st_mode), buf);
else
(void)printf(" d %s\n", buf);
}
lastdev = stb.st_dev;
(void)fflush(stdout);
break;
case S_IFLNK:
/*
* Sigh, another symlink. Read its contents and
* call namei()
*/
bzero(sym, BUFSIZ);
if(readlink(buf, sym, BUFSIZ) == -1){
(void)printf(_(" ? problems reading symlink %s - %s (%d)\n"), buf, ERR);
return;
}
if(mflag)
(void)printf(" l%s %s -> %s", pperm(stb.st_mode), buf, sym);
else
(void)printf(" l %s -> %s", buf, sym);
if(symcount > 0 && symcount++ > MAXSYMLINKS){
(void)printf(_(" *** EXCEEDED UNIX LIMIT OF SYMLINKS ***\n"));
} else {
(void)printf("\n");
namei(sym, lev + 1, lastmode);
}
if (symcount > MAXSYMLINKS)
return;
break;
case S_IFCHR:
if(mflag)
(void)printf(" c%s %s\n", pperm(stb.st_mode), buf);
else
(void)printf(" c %s\n", buf);
break;
case S_IFBLK:
if(mflag)
(void)printf(" b%s %s\n", pperm(stb.st_mode), buf);
else
(void)printf(" b %s\n", buf);
break;
case S_IFSOCK:
if(mflag)
(void)printf(" s%s %s\n", pperm(stb.st_mode), buf);
else
(void)printf(" s %s\n", buf);
break;
case S_IFIFO:
if (mflag)
printf(" p%s %s\n", pperm(stb.st_mode), buf);
else
printf(" p %s\n", buf);
break;
case S_IFREG:
if(mflag)
(void)printf(" -%s %s\n", pperm(stb.st_mode), buf);
else
(void)printf(" - %s\n", buf);
break;
default:
(void)fprintf(stderr,_("namei: unknown file type 0%06o on file %s\n"), stb.st_mode, buf );
exit(1);
}
}
}
/* Take a
* Mode word, as from a struct stat, and return
* a pointer to a static string containing a printable version like ls.
* For example 0755 produces "rwxr-xr-x"
*/
static char *
pperm(unsigned short mode) {
unsigned short m;
static char buf[16];
char *bp;
char *lschars = "xwrxwrxwr"; /* the complete string backwards */
char *cp;
int i;
for(i = 0, cp = lschars, m = mode, bp = &buf[8];
i < 9;
i++, cp++, m >>= 1, bp--) {
if(m & 1)
*bp = *cp;
else
*bp = '-';
}
buf[9] = '\0';
if(mode & S_ISUID) {
if(buf[2] == 'x')
buf[2] = 's';
else
buf[2] = 'S';
}
if(mode & S_ISGID) {
if(buf[5] == 'x')
buf[5] = 's';
else
buf[5] = 'S';
}
if(mode & S_ISVTX) {
if(buf[8] == 'x')
buf[8] = 't';
else
buf[8] = 'T';
}
return &buf[0];
}
