freebsd-dev/usr.bin/file/fsmagic.c

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/*
* fsmagic - magic based on filesystem info - directory, special files, etc.
*
* Copyright (c) Ian F. Darwin, 1987.
* Written by Ian F. Darwin.
*
* This software is not subject to any license of the American Telephone
* and Telegraph Company or of the Regents of the University of California.
*
* Permission is granted to anyone to use this software for any purpose on
* any computer system, and to alter it and redistribute it freely, subject
* to the following restrictions:
*
* 1. The author is not responsible for the consequences of use of this
* software, no matter how awful, even if they arise from flaws in it.
*
* 2. The origin of this software must not be misrepresented, either by
* explicit claim or by omission. Since few users ever read sources,
* credits must appear in the documentation.
*
* 3. Altered versions must be plainly marked as such, and must not be
* misrepresented as being the original software. Since few users
* ever read sources, credits must appear in the documentation.
*
* 4. This notice may not be removed or altered.
*/
#ifndef lint
static const char rcsid[] =
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"$FreeBSD$";
#endif /* not lint */
#include <err.h>
#include <string.h>
#include <sys/stat.h>
#include <unistd.h>
#include "file.h"
int
fsmagic(fn, sb)
const char *fn;
struct stat *sb;
{
int ret = 0;
/*
* Fstat is cheaper but fails for files you don't have read perms on.
* On 4.2BSD and similar systems, use lstat() to identify symlinks.
*/
#ifdef S_IFLNK
if (!lflag)
ret = lstat(fn, sb);
else
#endif
ret = stat(fn, sb); /* don't merge into if; see "ret =" above */
if (ret) {
ckfprintf(stdout,
/* Yes, I do mean stdout. */
/* No \n, caller will provide. */
"can't stat `%s': %s.", fn, strerror(errno));
return 1;
}
if (sb->st_mode & S_ISUID) ckfputs("setuid ", stdout);
if (sb->st_mode & S_ISGID) ckfputs("setgid ", stdout);
if (sb->st_mode & S_ISVTX) ckfputs("sticky ", stdout);
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switch (sb->st_mode & S_IFMT) {
case S_IFDIR:
ckfputs("directory", stdout);
return 1;
case S_IFCHR:
(void) printf("character special (%ld/%ld)",
(long) major(sb->st_rdev), (long) minor(sb->st_rdev));
return 1;
case S_IFBLK:
(void) printf("block special (%ld/%ld)",
(long) major(sb->st_rdev), (long) minor(sb->st_rdev));
return 1;
/* TODO add code to handle V7 MUX and Blit MUX files */
#ifdef S_IFIFO
case S_IFIFO:
ckfputs("fifo (named pipe)", stdout);
return 1;
#endif
#ifdef S_IFLNK
case S_IFLNK:
{
char buf[BUFSIZ+4];
register int nch;
struct stat tstatbuf;
if ((nch = readlink(fn, buf, BUFSIZ-1)) <= 0) {
ckfprintf(stdout, "unreadable symlink: %s.",
strerror(errno));
return 1;
}
buf[nch] = '\0'; /* readlink(2) forgets this */
/* If broken symlink, say so and quit early. */
if (*buf == '/') {
if (stat(buf, &tstatbuf) < 0) {
ckfprintf(stdout,
"broken symbolic link to %s", buf);
return 1;
}
}
else {
char *tmp;
char buf2[BUFSIZ+BUFSIZ+4];
if ((tmp = strrchr(fn, '/')) == NULL) {
tmp = buf; /* in current directory anyway */
}
else {
strcpy (buf2, fn); /* take directory part */
buf2[tmp-fn+1] = '\0';
strcat (buf2, buf); /* plus (relative) symlink */
tmp = buf2;
}
if (stat(tmp, &tstatbuf) < 0) {
ckfprintf(stdout,
"broken symbolic link to %s", buf);
return 1;
}
}
/* Otherwise, handle it. */
if (lflag) {
process(buf, strlen(buf));
return 1;
} else { /* just print what it points to */
ckfputs("symbolic link to ", stdout);
ckfputs(buf, stdout);
}
}
return 1;
#endif
#ifdef S_IFSOCK
#ifndef __COHERENT__
case S_IFSOCK:
ckfputs("socket", stdout);
return 1;
#endif
#endif
case S_IFREG:
break;
default:
err(1, "invalid mode 0%o", sb->st_mode);
/*NOTREACHED*/
}
/*
* regular file, check next possibility
*/
if (sb->st_size == 0) {
ckfputs("empty", stdout);
return 1;
}
return 0;
}