diff options
Diffstat (limited to 'file/fsmagic.c')
| -rw-r--r-- | file/fsmagic.c | 251 |
1 files changed, 251 insertions, 0 deletions
diff --git a/file/fsmagic.c b/file/fsmagic.c new file mode 100644 index 000000000..c7869dd50 --- /dev/null +++ b/file/fsmagic.c @@ -0,0 +1,251 @@ +/* + * 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. + */ + +#include "file.h" +#include <stdio.h> +#include <string.h> +#include <sys/types.h> +#include <sys/stat.h> +#ifdef HAVE_UNISTD_H +#include <unistd.h> +#endif +#include <stdlib.h> +/* Since major is a function on SVR4, we can't use `ifndef major'. */ +#ifdef MAJOR_IN_MKDEV +# include <sys/mkdev.h> +# define HAVE_MAJOR +#endif +#ifdef MAJOR_IN_SYSMACROS +# include <sys/sysmacros.h> +# define HAVE_MAJOR +#endif +#ifdef major /* Might be defined in sys/types.h. */ +# define HAVE_MAJOR +#endif + +#ifndef HAVE_MAJOR +# define major(dev) (((dev) >> 8) & 0xff) +# define minor(dev) ((dev) & 0xff) +#endif +#undef HAVE_MAJOR + +#ifndef lint +FILE_RCSID("@(#)Id: fsmagic.c,v 1.33 2000/08/05 17:36:48 christos Exp ") +#endif /* lint */ + +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 (iflag) { + if ((sb->st_mode & S_IFMT) != S_IFREG) { + ckfputs("application/x-not-regular-file", stdout); + return 1; + } + } + else { +#ifdef S_ISUID + if (sb->st_mode & S_ISUID) ckfputs("setuid ", stdout); +#endif +#ifdef S_ISGID + if (sb->st_mode & S_ISGID) ckfputs("setgid ", stdout); +#endif +#ifdef S_ISVTX + if (sb->st_mode & S_ISVTX) ckfputs("sticky ", stdout); +#endif + } + + switch (sb->st_mode & S_IFMT) { + case S_IFDIR: + ckfputs("directory", stdout); + return 1; +#ifdef S_IFCHR + case S_IFCHR: + /* + * If -s has been specified, treat character special files + * like ordinary files. Otherwise, just report that they + * are block special files and go on to the next file. + */ + if (sflag) + break; +#ifdef HAVE_ST_RDEV +# ifdef dv_unit + (void) printf("character special (%d/%d/%d)", + major(sb->st_rdev), + dv_unit(sb->st_rdev), + dv_subunit(sb->st_rdev)); +# else + (void) printf("character special (%ld/%ld)", + (long) major(sb->st_rdev), (long) minor(sb->st_rdev)); +# endif +#else + (void) printf("character special"); +#endif + return 1; +#endif +#ifdef S_IFBLK + case S_IFBLK: + /* + * If -s has been specified, treat block special files + * like ordinary files. Otherwise, just report that they + * are block special files and go on to the next file. + */ + if (sflag) + break; +#ifdef HAVE_ST_RDEV +# ifdef dv_unit + (void) printf("block special (%d/%d/%d)", + major(sb->st_rdev), + dv_unit(sb->st_rdev), + dv_subunit(sb->st_rdev)); +# else + (void) printf("block special (%ld/%ld)", + (long) major(sb->st_rdev), (long) minor(sb->st_rdev)); +# endif +#else + (void) printf("block special"); +#endif + return 1; +#endif + /* 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_IFDOOR + case S_IFDOOR: + ckfputs("door", stdout); + return 1; +#endif +#ifdef S_IFLNK + case S_IFLNK: + { + char buf[BUFSIZ+4]; + 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: + error("invalid mode 0%o.\n", sb->st_mode); + /*NOTREACHED*/ + } + + /* + * regular file, check next possibility + * + * If stat() tells us the file has zero length, report here that + * the file is empty, so we can skip all the work of opening and + * reading the file. + * But if the -s option has been given, we skip this optimization, + * since on some systems, stat() reports zero size for raw disk + * partitions. (If the block special device really has zero length, + * the fact that it is empty will be detected and reported correctly + * when we read the file.) + */ + if (!sflag && sb->st_size == 0) { + ckfputs(iflag ? "application/x-empty" : "empty", stdout); + return 1; + } + return 0; +} |