toys/posix/file.c - platform/external/toybox - Git at Google

 /* file.c - describe file type
  *
  * Copyright 2016 The Android Open Source Project
  *
  * See http://pubs.opengroup.org/onlinepubs/9699919799/utilities/file.html

 USE_FILE(NEWTOY(file, "<1b(brief)hLs[!hL]", TOYFLAG_USR|TOYFLAG_BIN))

 config FILE
   bool "file"
   default y
   help
     usage: file [-bhLs] [FILE...]

     Examine the given files and describe their content types.

     -b	Brief (no filename)
     -h	Don't follow symlinks (default)
     -L	Follow symlinks
     -s	Show block/char device contents
 */

 #define FOR_file
 #include "toys.h"

 GLOBALS(
   int max_name_len;
   off_t len;
 )

 // We don't trust elf.h to be there, and two codepaths for 32/64 is awkward
 // anyway, so calculate struct offsets manually. (It's a fixed ABI.)
 static void do_elf_file(int fd)
 {
   unsigned endian = toybuf[5], bits = toybuf[4]-1, i, j, dynamic = 0,
            stripped = 1, phentsize, phnum, shsize, shnum, bail = 0, arch;
   long long (*elf_int)(void *ptr, unsigned size) = (endian==2)?peek_be:peek_le;
   char *map = MAP_FAILED;
   unsigned long phoff, shoff;

   printf("ELF ");

   // executable type
   i = elf_int(toybuf+16, 2);
   if (i == 1) printf("relocatable");
   else if (i == 2) printf("executable");
   else if (i == 3) printf("shared object");
   else if (i == 4) printf("core dump");
   else {
     printf("(bad type %d)", i);
     bail++;
   }
   if (elf_int(toybuf+36+12*!!bits, 4) & 0x8000) printf(" (fdpic)");
   printf(", ");

   // "64-bit"
   if (bits&~1) {
     printf("(bad class %d) ", bits);
     bail++;
   } else printf("%d-bit ", 32<<bits);

   // "LSB"
   if (endian == 1) printf("LSB ");
   else if (endian == 2) printf("MSB ");
   else {
     printf("(bad endian %d) ", endian);
     bail++;
   }

   // "x86".
   printf("%s", elf_arch_name(arch = elf_int(toybuf+18, 2)));
   elf_print_flags(arch, elf_int(toybuf+36+12*bits, 4));

   // If what we've seen so far doesn't seem consistent, bail.
   if (bail) goto bad;

   // Stash what we need from the header; it's okay to reuse toybuf after this.
   phentsize = elf_int(toybuf+42+12*bits, 2);
   phnum = elf_int(toybuf+44+12*bits, 2);
   phoff = elf_int(toybuf+28+4*bits, 4+4*bits);
   shsize = elf_int(toybuf+46+12*bits, 2);
   shnum = elf_int(toybuf+48+12*bits, 2);
   shoff = elf_int(toybuf+32+8*bits, 4+4*bits);

   // With binutils, phentsize seems to only be non-zero if phnum is non-zero.
   // Such ELF files are rare, but do exist. (Android's crtbegin files, say.)
   if (phnum && (phentsize != 32+24*bits)) {
     printf(", bad phentsize %d?", phentsize);
     goto bad;
   }
   if (phoff>TT.len || phnum*phentsize>TT.len-phoff) {
     printf(", bad phoff %lu?", phoff);
     goto bad;
   }
   if (shoff>TT.len || shnum*shsize>TT.len-shoff) {
     printf(", bad shoff %lu?", phoff);
     goto bad;
   }

   // Parsing ELF means following tables that may point to data earlier in
   // the file, so sequential reading involves buffering unknown amounts of
   // data. Just skip it if we can't mmap.
   if (MAP_FAILED == (map = mmap(0, TT.len, PROT_READ, MAP_SHARED, fd, 0))) {
     perror_msg("mmap");
     goto bad;
   }

   // Read the phdrs for dynamic vs static. (Note: fields reordered on 64 bit)
   for (i = 0; i<phnum; i++) {
     char *phdr = map+phoff+i*phentsize;
     unsigned p_type = elf_int(phdr, 4);
     unsigned long long p_offset, p_filesz;

     // TODO: what does PT_DYNAMIC without PT_INTERP mean?
     if (p_type-2>2) continue; // 2 = PT_DYNAMIC, 3 = PT_INTERP, 4 = PT_NOTE
     dynamic |= p_type==2;
     p_offset = elf_int(phdr+(4<<bits), 4<<bits);
     p_filesz = elf_int(phdr+(16<<bits), 4<<bits);
     if (p_type==3) {
       if (p_filesz>TT.len || p_offset>TT.len-p_filesz) {
         printf(", bad phdr %d?", i);
         goto bad;
       }
       // TODO: if (int)<0 prints endlessly, could go off end of map?
       printf(", dynamic (%.*s)", (int)p_filesz, map+p_offset);
     }
   }
   if (!dynamic) printf(", static");

   // We need to read the shdrs for stripped/unstripped and any notes.
   // Notes are in program headers *and* section headers, but some files don't
   // contain program headers, so check here. (Note: fields reordered on 64 bit)
   for (i = 0; i<shnum; i++) {
     char *shdr = map+shoff+i*shsize;
     unsigned long sh_offset;
     int sh_type, sh_size;

     if (shdr>map+TT.len-(8+(4<<bits))) {
       printf(", bad shdr %d?", i);
       goto bad;
     }
     sh_type = elf_int(shdr+4, 4);
     sh_offset = elf_int(shdr+8+(8<<bits), 4<<bits);
     sh_size = elf_int(shdr+8+(12<<bits), 4);
     if (sh_type == 8 /*SHT_NOBITS*/) sh_size = 0;
     if (sh_offset>TT.len || sh_size>TT.len-sh_offset) {
       printf(", bad shdr %d?", i);
       goto bad;
     }

     if (sh_type == 2 /*SHT_SYMTAB*/) {
       stripped = 0;
       break;
     } else if (sh_type == 7 /*SHT_NOTE*/) {
       char *note = map+sh_offset;

       // An ELF note is a sequence of entries, each consisting of an
       // ndhr followed by n_namesz+n_descsz bytes of data (each of those
       // rounded up to the next 4 bytes, without this being reflected in
       // the header byte counts themselves).
       while (sh_size >= 3*4) { // Don't try to read a truncated entry.
         unsigned n_namesz, n_descsz, n_type, notesz;

         if (note>map+TT.len-3*4) {
           printf(", bad note %d?", i);
           goto bad;
         }

         n_namesz = elf_int(note, 4);
         n_descsz = elf_int(note+4, 4);
         n_type = elf_int(note+8, 4);
         notesz = 3*4 + ((n_namesz+3)&~3) + ((n_descsz+3)&~3);

         // Are the name/desc sizes consistent, and does the claimed size of
         // the note actually fit in the section?
         if (notesz<n_namesz || notesz<n_descsz || notesz>sh_size) {
           printf(", bad note %d size?", i);
           goto bad;
         }

         if (n_namesz==4 && !smemcmp(note+12, "GNU", 4) && n_type==3) {
           printf(", BuildID=");
           for (j = 0; j<n_descsz; j++) printf("%02x", note[16+j]);
         } else if (n_namesz==8 && !smemcmp(note+12, "Android", 8)) {
           if (n_type==1 /*.android.note.ident*/ && n_descsz >= 4) {
             printf(", for Android %d", (int)elf_int(note+20, 4));
             // NDK r14 and later also include NDK version info. OS binaries
             // and binaries built by older NDKs don't have this.
             if (n_descsz >= 4+64+64)
               printf(", built by NDK %.64s (%.64s)", note+24, note+24+64);
           }
         }

         note += notesz;
         sh_size -= notesz;
       }
     }
   }
   printf(", %sstripped", stripped ? "" : "not ");
 bad:
   xputc('\n');

   if (map != MAP_FAILED) munmap(map, TT.len);
 }

 static void do_regular_file(int fd, char *name)
 {
   char *s = toybuf;
   unsigned len, magic;
   int ii;

   // zero through elf shnum, just in case
   memset(s, 0, 80);
   if ((len = readall(fd, s, sizeof(toybuf)-8))<0) perror_msg_raw(name);

   if (!len) xputs("empty");
   // 45 bytes: https://www.muppetlabs.com/~breadbox/software/tiny/teensy.html
   else if (len>=45 && strstart(&s, "\177ELF")) do_elf_file(fd);
   else if (strstart(&s, "!<arch>\n")) xputs("ar archive");
   else if (*s=='%' && 2==sscanf(s, "%%PDF%d.%u", &ii, &magic))
     xprintf("PDF document, version %d.%u\n", -ii, magic);
   else if (len>28 && strstart(&s, "\x89PNG\x0d\x0a\x1a\x0a")) {
     // PNG is big-endian: https://www.w3.org/TR/PNG/#7Integers-and-byte-order
     int chunk_length = peek_be(s, 4);

     xprintf("PNG image data");

     // The IHDR chunk comes first: https://www.w3.org/TR/PNG/#11IHDR
     s += 4;
     if (chunk_length == 13 && strstart(&s, "IHDR")) {
       // https://www.w3.org/TR/PNG/#6Colour-values
       char *c = 0, *colors[] = {"grayscale", 0, "color RGB", "indexed color",
                                 "grayscale with alpha", 0, "color RGBA"};

       if (s[9]<ARRAY_LEN(colors)) c = colors[s[9]];
       xprintf(", %d x %d, %d-bit/%s, %sinterlaced", (int)peek_be(s, 4),
         (int)peek_be(s+4, 4), s[8], c ? : "unknown", s[12] ? "" : "non-");
     }

     xputc('\n');

   // https://www.w3.org/Graphics/GIF/spec-gif89a.txt
   } else if (len>16 && (strstart(&s, "GIF87a") || strstart(&s, "GIF89a")))
     xprintf("GIF image data, version %3.3s, %d x %d\n",
       s-3, (int)peek_le(s, 2), (int)peek_le(s+2, 2));

   // https://en.wikipedia.org/wiki/JPEG#Syntax_and_structure
   else if (len>32 && !smemcmp(s, "\xff\xd8", 2)) {
     char *types[] = {"baseline", "extended sequential", "progressive"};
     int marker;

     printf("JPEG image data");
     while (s < toybuf+len-8) { // TODO: refill for files with lots of EXIF data?
       marker = peek_be(s, 2);
       if (marker >= 0xffd0 && marker <= 0xffd9) s += 2; // No data.
       else if (marker >= 0xffc0 && marker <= 0xffc2) {
         xprintf(", %s, %dx%d", types[marker-0xffc0], (int) peek_be(s+7, 2),
                 (int) peek_be(s+5, 2));
         break;
       } else s += peek_be(s + 2, 2) + 2;
     }
     xputc('\n');

   } else if (len>8 && strstart(&s, "\xca\xfe\xba\xbe")) {
     unsigned count = peek_be(s, 4), i, arch;

     // 0xcafebabe can be a Java class file or a Mach-O universal binary.
     // Java major version numbers start with 0x2d for JDK 1.1, and realistically
     // you're never going to see more than 2 architectures in a binary anyway...
     if (count<0x2d && len>=(count*20)) {
       // https://eclecticlight.co/2020/07/28/universal-binaries-inside-fat-headers/
       xprintf("Mach-O universal binary with %u architecture%s:",
         count, count == 1 ? "" : "s");
       for (i = 0, s += 4; i < count; i++, s += 20) {
         arch = peek_be(s, 4);
         if (arch == 0x00000007) name = "i386";
         else if (arch == 0x01000007) name = "x86_64";
         else if (arch == 0x0000000c) name = "arm";
         else if (arch == 0x0100000c) name = "arm64";
         else name = "unknown";
         xprintf(" [%s]", name);
       }
       xprintf("\n");
     } else {
       // https://en.wikipedia.org/wiki/Java_class_file#General_layout
       xprintf("Java class file, version %d.%d (Java 1.%d)\n",
         (int)peek_be(s+2, 2), (int)peek_be(s, 2), (int)peek_be(s+2, 2)-44);
     }

   // https://source.android.com/devices/tech/dalvik/dex-format#dex-file-magic
   } else if (len>8 && strstart(&s, "dex\n") && !s[3])
     xprintf("Android dex file, version %s\n", s);

   // https://people.freebsd.org/~kientzle/libarchive/man/cpio.5.txt
   // the lengths for cpio are size of header + 9 bytes, since any valid
   // cpio archive ends with a record for "TARGET!!!"
   else if (len>6 && strstart(&s, "07070")) {
     char *cpioformat = "unknown type";

     if (*s == '7') cpioformat = "pre-SVR4 or odc";
     else if (*s == '1') cpioformat = "SVR4 with no CRC";
     else if (*s == '2') cpioformat = "SVR4 with CRC";
     xprintf("ASCII cpio archive (%s)\n", cpioformat);
   } else if (len>33 && ((magic=peek(&s,2))==0143561 || magic==070707)) {
     if (magic == 0143561) printf("byte-swapped ");
     xputs("cpio archive");
   // tar archive (old, ustar/pax, or gnu)
   } else if (len>500 && is_tar_header(s))
     xprintf("%s tar archive%s\n", s[257] ? "POSIX" : "old",
       (s[262]!=' ' || s[263]!=' ')?"":" (GNU)");
   // zip/jar/apk archive, ODF/OOXML document, or such
   else if (len>5 && strstart(&s, "PK\03\04")) {
     xprintf("Zip archive data");
     if (*s) xprintf(", requires at least v%d.%d to extract", *s/10, *s%10);
     xputc('\n');
   } else if (len>9 && strstart(&s, "7z\xbc\xaf\x27\x1c")) {
     xprintf("7-zip archive data");
     if (*s || s[1]) xprintf(", version %d.%d", *s, s[1]);
     xputc('\n');
   } else if (len>4 && strstart(&s, "BZh") && isdigit(*s))
     xprintf("bzip2 compressed data, block size = %c00k\n", *s);
   else if (len>31 && peek_be(s, 7) == 0xfd377a585a0000ULL)
     xputs("xz compressed data");
   else if (len>10 && strstart(&s, "\x1f\x8b")) xputs("gzip compressed data");
   else if (len>32 && !smemcmp(s+1, "\xfa\xed\xfe", 3)) {
     int bit = (*s==0xce) ? 32 : 64;
     char *what = 0;

     xprintf("Mach-O %d-bit ", bit);

     if (s[4] == 7) what = (bit==32)?"x86":"x86-";
     else if (s[4] == 12) what = "arm";
     else if (s[4] == 18) what = "ppc";
     if (what) xprintf("%s%s ", what, (bit==32)?"":"64");
     else xprintf("(bad arch %d) ", s[4]);

     if (s[12] == 1) what = "object";
     else if (s[12] == 2) what = "executable";
     else if (s[12] == 6) what = "shared library";
     else what = NULL;
     if (what) xprintf("%s\n", what);
     else xprintf("(bad type %d)\n", s[9]);
   } else if (len>36 && !smemcmp(s, "OggS\x00\x02", 6)) {
     xprintf("Ogg data");
     // https://wiki.xiph.org/MIMETypesCodecs
     if (!smemcmp(s+28, "CELT    ", 8)) xprintf(", celt audio");
     else if (!smemcmp(s+28, "CMML    ", 8)) xprintf(", cmml text");
     else if (!smemcmp(s+28, "BBCD", 5)) xprintf(", dirac video");
     else if (!smemcmp(s+28, "\177FLAC", 5)) xprintf(", flac audio");
     else if (!smemcmp(s+28, "\x8bJNG\r\n\x1a\n", 8)) xprintf(", jng video");
     else if (!smemcmp(s+28, "\x80kate\0\0", 8)) xprintf(", kate text");
     else if (!smemcmp(s+28, "OggMIDI", 8)) xprintf(", midi text");
     else if (!smemcmp(s+28, "\x8aMNG\r\n\x1a\n", 8)) xprintf(", mng video");
     else if (!smemcmp(s+28, "OpusHead", 8)) xprintf(", opus audio");
     else if (!smemcmp(s+28, "PCM     ", 8)) xprintf(", pcm audio");
     else if (!smemcmp(s+28, "\x89PNG\r\n\x1a\n", 8)) xprintf(", png video");
     else if (!smemcmp(s+28, "Speex   ", 8)) xprintf(", speex audio");
     else if (!smemcmp(s+28, "\x80theora", 7)) xprintf(", theora video");
     else if (!smemcmp(s+28, "\x01vorbis", 7)) xprintf(", vorbis audio");
     else if (!smemcmp(s+28, "YUV4MPEG", 8)) xprintf(", yuv4mpeg video");
     xputc('\n');
   } else if (len>32 && !smemcmp(s, "RIF", 3) && !smemcmp(s+8, "WAVEfmt ", 8)) {
     // https://en.wikipedia.org/wiki/WAV
     int le = (s[3] == 'F');
     int format = le ? peek_le(s+20, 2) : peek_be(s+20, 2);
     int channels = le ? peek_le(s+22, 2) : peek_be(s+22, 2);
     int hz = le ? peek_le(s+24, 4) : peek_be(s+24, 4);
     int bits = le ? peek_le(s+34, 2) : peek_be(s+34, 2);

     xprintf("WAV audio, %s, ", le ? "LE" : "BE");
     if (bits) xprintf("%d-bit, ", bits);
     if (channels==1||channels==2) xprintf("%s, ",(channels==1)?"mono":"stereo");
     else xprintf("%d-channel, ", channels);
     xprintf("%d Hz, ", hz);
     // See https://tools.ietf.org/html/rfc2361, though there appear to be bugs
     // in the RFC. This assumes wikipedia's example files are more correct.
     if (format == 0x01) xprintf("PCM");
     else if (format == 0x03) xprintf("IEEE float");
     else if (format == 0x06) xprintf("A-law");
     else if (format == 0x07) xprintf("µ-law");
     else if (format == 0x11) xprintf("ADPCM");
     else if (format == 0x22) xprintf("Truespeech");
     else if (format == 0x31) xprintf("GSM");
     else if (format == 0x55) xprintf("MP3");
     else if (format == 0x70) xprintf("CELP");
     else if (format == 0xfffe) xprintf("extensible");
     else xprintf("unknown format %d", format);
     xputc('\n');
   } else if (len>12 && peek_be(s, 4)==0x10000) xputs("TrueType font");
   else if (len>12 && !smemcmp(s, "ttcf", 5)) {
     xprintf("TrueType font collection, version %d, %d fonts\n",
             (int)peek_be(s+4, 2), (int)peek_be(s+8, 4));

   // https://docs.microsoft.com/en-us/typography/opentype/spec/otff
   } else if (len>12 && strstart(&s, "OTTO")) xputs("OpenType font");
   else if (strstart(&s, "BC\xc0\xde")) xputs("LLVM IR bitcode");
   else if (strstart(&s,"-----BEGIN CERTIFICATE-----")) xputs("PEM certificate");

   // https://msdn.microsoft.com/en-us/library/windows/desktop/ms680547(v=vs.85).aspx
   else if (len>0x70 && !smemcmp(s, "MZ", 2) &&
       (magic=peek_le(s+0x3c,4))<len-4 && !smemcmp(s+magic, "\x50\x45\0", 4)) {

     // Linux kernel images look like PE files.
     // https://www.kernel.org/doc/Documentation/arm64/booting.txt
     // I've only ever seen LE, 4KiB pages, so ignore flags for now.
     if (!smemcmp(s+0x38, "ARMd", 4)) return xputs("Linux arm64 kernel image");
     else if (!smemcmp(s+0x202, "HdrS", 4)) {
       // https://www.kernel.org/doc/Documentation/x86/boot.txt
       unsigned ver_off = peek_le(s+0x20e, 2);

       xprintf("Linux x86-64 kernel image");
       if ((0x200 + ver_off) < len) {
         s += 0x200 + ver_off;
       } else {
         if (lseek(fd, ver_off - len + 0x200, SEEK_CUR)<0 ||
             (len = readall(fd, s, sizeof(toybuf)))<0)
           return perror_msg_raw(name);
       }
       xprintf(", version %s\n", s);
       return;
     }

     xprintf("MS PE32%s executable %s", (peek_le(s+magic+24, 2)==0x20b)?"+":"",
         (peek_le(s+magic+22, 2)&0x2000)?"(DLL) ":"");
     if (peek_le(s+magic+20, 2)>70) {
       char *types[] = {0, "native", "GUI", "console", "OS/2", "driver", "CE",
           "EFI", "EFI boot", "EFI runtime", "EFI ROM", "XBOX", 0, "boot"}, *nn;
       unsigned type = peek_le(s+magic+92, 2);

       nn = (type<ARRAY_LEN(types)) ? types[type] : 0;
       xprintf("(%s) ", nn ? : "unknown");
     }
     xprintf("x86%s\n", (peek_le(s+magic+4, 2)==0x14c) ? "" : "-64");

     // https://en.wikipedia.org/wiki/BMP_file_format
   } else if (len>0x32 && !smemcmp(s, "BM", 2) && !peek_be(s+6, 4)) {
     xprintf("BMP image, %d x %d, %d bpp\n", (int)peek_le(s+18, 4),
             (int)peek_le(s+22,4), (int)peek_le(s+28, 2));

     // https://github.com/torvalds/linux/blob/master/tools/perf/Documentation/perf.data-file-format.txt
   } else if (len>=104 && strstart(&s, "PERFILE2")) xputs("Linux perf data");

     // https://android.googlesource.com/platform/system/core/+/master/libsparse/sparse_format.h
   else if (len>28 && peek_le(s, 4) == 0xed26ff3a) {
     xprintf("Android sparse image v%d.%d, %d %d-byte blocks (%d chunks)\n",
         (int)peek_le(s+4, 2), (int)peek_le(s+6, 2), (int)peek_le(s+16, 4),
         (int)peek_le(s+12, 4), (int)peek_le(s+20, 4));

     // https://android.googlesource.com/platform/system/tools/mkbootimg/+/refs/heads/master/include/bootimg/bootimg.h
   } else if (len>1632 && !smemcmp(s, "ANDROID!", 8)) {
     xprintf("Android boot image v%d\n", (int)peek_le(s+40, 4));

     // https://source.android.com/devices/architecture/dto/partitions
   } else if (len>32 && peek_be(s, 4) == 0xd7b7ab1e) {
     xprintf("Android DTB/DTBO v%d, %d entries\n", (int)peek_be(s+28, 4),
             (int)peek_be(s+16, 4));

     // frameworks/base/core/java/com/android/internal/util/BinaryXmlSerializer.java
   } else if (len>4 && !smemcmp(s, "ABX", 3)) {
     xprintf("Android Binary XML v%d\n", s[3]);

     // https://webassembly.github.io/spec/core/binary/modules.html#binary-module
   } else if (len>8 && !smemcmp(s, "\0asm", 4)) {
     xprintf("wasm binary module version %d\n", (int)peek_le(s+4, 4));

     // Text files, including shell scripts.
   } else {
     char *what = 0;
     int i, bytes;

     // If shell script, report which interpreter
     if (len>3 && strstart(&s, "#!")) {
       // Whitespace is allowed between the #! and the interpreter
       while (isspace(*s)) s++;
       if (strstart(&s, "/usr/bin/env")) while (isspace(*s)) s++;
       for (what = s; *s && !isspace(*s); s++);
       strcpy(s, " script");

     // Distinguish ASCII text, UTF-8 text, or data
     } else for (i = 0; i<len; ++i) {
       if (!(isprint(s[i]) || isspace(s[i]))) {
         unsigned wc;

         if ((bytes = utf8towc(&wc, s+i, len-i))>0 && wcwidth(wc)>=0) {
           i += bytes-1;
           if (!what) what = "UTF-8 text";
         } else {
           what = "data";
           break;
         }
       }
     }
     xputs(what ? what : "ASCII text");
   }
 }

 void file_main(void)
 {
   char **arg;

   for (arg = toys.optargs; *arg; ++arg)
     TT.max_name_len = maxof(strlen(*arg), TT.max_name_len);

   // Can't use loopfiles here because it doesn't call function when can't open
   for (arg = toys.optargs; *arg; arg++) {
     char *name = *arg, *what = "unknown";
     struct stat sb;
     int fd = !strcmp(name, "-");

     if (!FLAG(b))
       xprintf("%s: %*s", name, (int)(TT.max_name_len - strlen(name)), "");

     sb.st_size = 0;
     if (!fd && (FLAG(L) ? stat : lstat)(name, &sb)) {
       xprintf("cannot open: %s\n", strerror(errno));

       continue;
     }

     if (!fd && !FLAG(s) && (S_ISBLK(sb.st_mode) || S_ISCHR(sb.st_mode))) {
       sprintf(what = toybuf, "%s special (%u/%u)",
           S_ISBLK(sb.st_mode) ? "block" : "character",
           dev_major(sb.st_rdev), dev_minor(sb.st_rdev));
     } else if (fd || S_ISREG(sb.st_mode)) {
       TT.len = sb.st_size;
       // This test identifies an empty file we don't have permission to read
       if (!fd && !sb.st_size) what = "empty";
       else if ((fd = openro(name, O_RDONLY)) != -1) {
         do_regular_file(fd, name);
         if (fd) close(fd);

         continue;
       }
     } else if (S_ISFIFO(sb.st_mode)) what = "fifo";
     else if (S_ISDIR(sb.st_mode)) what = "directory";
     else if (S_ISSOCK(sb.st_mode)) what = "socket";
     else if (S_ISLNK(sb.st_mode)) {
       char *lnk = xreadlink(name);

       sprintf(what = toybuf, "%ssymbolic link to %s",
           stat(name, &sb) ? "broken " : "", lnk);
       free(lnk);
     }
     xputs(what);
   }
 }
	/* file.c - describe file type
	*
	* Copyright 2016 The Android Open Source Project
	*
	* See http://pubs.opengroup.org/onlinepubs/9699919799/utilities/file.html

	USE_FILE(NEWTOY(file, "<1b(brief)hLs[!hL]", TOYFLAG_USR\|TOYFLAG_BIN))

	config FILE
	bool "file"
	default y
	help
	usage: file [-bhLs] [FILE...]

	Examine the given files and describe their content types.

	-b Brief (no filename)
	-h Don't follow symlinks (default)
	-L Follow symlinks
	-s Show block/char device contents
	*/

	#define FOR_file
	#include "toys.h"

	GLOBALS(
	int max_name_len;
	off_t len;
	)

	// We don't trust elf.h to be there, and two codepaths for 32/64 is awkward
	// anyway, so calculate struct offsets manually. (It's a fixed ABI.)
	static void do_elf_file(int fd)
	{
	unsigned endian = toybuf[5], bits = toybuf[4]-1, i, j, dynamic = 0,
	stripped = 1, phentsize, phnum, shsize, shnum, bail = 0, arch;
	long long (elf_int)(void ptr, unsigned size) = (endian==2)?peek_be:peek_le;
	char *map = MAP_FAILED;
	unsigned long phoff, shoff;

	printf("ELF ");

	// executable type
	i = elf_int(toybuf+16, 2);
	if (i == 1) printf("relocatable");
	else if (i == 2) printf("executable");
	else if (i == 3) printf("shared object");
	else if (i == 4) printf("core dump");
	else {
	printf("(bad type %d)", i);
	bail++;
	}
	if (elf_int(toybuf+36+12*!!bits, 4) & 0x8000) printf(" (fdpic)");
	printf(", ");

	// "64-bit"
	if (bits&~1) {
	printf("(bad class %d) ", bits);
	bail++;
	} else printf("%d-bit ", 32<<bits);

	// "LSB"
	if (endian == 1) printf("LSB ");
	else if (endian == 2) printf("MSB ");
	else {
	printf("(bad endian %d) ", endian);
	bail++;
	}

	// "x86".
	printf("%s", elf_arch_name(arch = elf_int(toybuf+18, 2)));
	elf_print_flags(arch, elf_int(toybuf+36+12*bits, 4));

	// If what we've seen so far doesn't seem consistent, bail.
	if (bail) goto bad;

	// Stash what we need from the header; it's okay to reuse toybuf after this.
	phentsize = elf_int(toybuf+42+12*bits, 2);
	phnum = elf_int(toybuf+44+12*bits, 2);
	phoff = elf_int(toybuf+28+4bits, 4+4bits);
	shsize = elf_int(toybuf+46+12*bits, 2);
	shnum = elf_int(toybuf+48+12*bits, 2);
	shoff = elf_int(toybuf+32+8bits, 4+4bits);

	// With binutils, phentsize seems to only be non-zero if phnum is non-zero.
	// Such ELF files are rare, but do exist. (Android's crtbegin files, say.)
	if (phnum && (phentsize != 32+24*bits)) {
	printf(", bad phentsize %d?", phentsize);
	goto bad;
	}
	if (phoff>TT.len \|\| phnum*phentsize>TT.len-phoff) {
	printf(", bad phoff %lu?", phoff);
	goto bad;
	}
	if (shoff>TT.len \|\| shnum*shsize>TT.len-shoff) {
	printf(", bad shoff %lu?", phoff);
	goto bad;
	}

	// Parsing ELF means following tables that may point to data earlier in
	// the file, so sequential reading involves buffering unknown amounts of
	// data. Just skip it if we can't mmap.
	if (MAP_FAILED == (map = mmap(0, TT.len, PROT_READ, MAP_SHARED, fd, 0))) {
	perror_msg("mmap");
	goto bad;
	}

	// Read the phdrs for dynamic vs static. (Note: fields reordered on 64 bit)
	for (i = 0; i<phnum; i++) {
	char phdr = map+phoff+iphentsize;
	unsigned p_type = elf_int(phdr, 4);
	unsigned long long p_offset, p_filesz;

	// TODO: what does PT_DYNAMIC without PT_INTERP mean?
	if (p_type-2>2) continue; // 2 = PT_DYNAMIC, 3 = PT_INTERP, 4 = PT_NOTE
	dynamic \|= p_type==2;
	p_offset = elf_int(phdr+(4<<bits), 4<<bits);
	p_filesz = elf_int(phdr+(16<<bits), 4<<bits);
	if (p_type==3) {
	if (p_filesz>TT.len \|\| p_offset>TT.len-p_filesz) {
	printf(", bad phdr %d?", i);
	goto bad;
	}
	// TODO: if (int)<0 prints endlessly, could go off end of map?
	printf(", dynamic (%.*s)", (int)p_filesz, map+p_offset);
	}
	}
	if (!dynamic) printf(", static");

	// We need to read the shdrs for stripped/unstripped and any notes.
	// Notes are in program headers and section headers, but some files don't
	// contain program headers, so check here. (Note: fields reordered on 64 bit)
	for (i = 0; i<shnum; i++) {
	char shdr = map+shoff+ishsize;
	unsigned long sh_offset;
	int sh_type, sh_size;

	if (shdr>map+TT.len-(8+(4<<bits))) {
	printf(", bad shdr %d?", i);
	goto bad;
	}
	sh_type = elf_int(shdr+4, 4);
	sh_offset = elf_int(shdr+8+(8<<bits), 4<<bits);
	sh_size = elf_int(shdr+8+(12<<bits), 4);
	if (sh_type == 8 /SHT_NOBITS/) sh_size = 0;
	if (sh_offset>TT.len \|\| sh_size>TT.len-sh_offset) {
	printf(", bad shdr %d?", i);
	goto bad;
	}

	if (sh_type == 2 /SHT_SYMTAB/) {
	stripped = 0;
	break;
	} else if (sh_type == 7 /SHT_NOTE/) {
	char *note = map+sh_offset;

	// An ELF note is a sequence of entries, each consisting of an
	// ndhr followed by n_namesz+n_descsz bytes of data (each of those
	// rounded up to the next 4 bytes, without this being reflected in
	// the header byte counts themselves).
	while (sh_size >= 3*4) { // Don't try to read a truncated entry.
	unsigned n_namesz, n_descsz, n_type, notesz;

	if (note>map+TT.len-3*4) {
	printf(", bad note %d?", i);
	goto bad;
	}

	n_namesz = elf_int(note, 4);
	n_descsz = elf_int(note+4, 4);
	n_type = elf_int(note+8, 4);
	notesz = 3*4 + ((n_namesz+3)&~3) + ((n_descsz+3)&~3);

	// Are the name/desc sizes consistent, and does the claimed size of
	// the note actually fit in the section?
	if (notesz<n_namesz \|\| notesz<n_descsz \|\| notesz>sh_size) {
	printf(", bad note %d size?", i);
	goto bad;
	}

	if (n_namesz==4 && !smemcmp(note+12, "GNU", 4) && n_type==3) {
	printf(", BuildID=");
	for (j = 0; j<n_descsz; j++) printf("%02x", note[16+j]);
	} else if (n_namesz==8 && !smemcmp(note+12, "Android", 8)) {
	if (n_type==1 /.android.note.ident/ && n_descsz >= 4) {
	printf(", for Android %d", (int)elf_int(note+20, 4));
	// NDK r14 and later also include NDK version info. OS binaries
	// and binaries built by older NDKs don't have this.
	if (n_descsz >= 4+64+64)
	printf(", built by NDK %.64s (%.64s)", note+24, note+24+64);
	}
	}

	note += notesz;
	sh_size -= notesz;
	}
	}
	}
	printf(", %sstripped", stripped ? "" : "not ");
	bad:
	xputc('\n');

	if (map != MAP_FAILED) munmap(map, TT.len);
	}

	static void do_regular_file(int fd, char *name)
	{
	char *s = toybuf;
	unsigned len, magic;
	int ii;

	// zero through elf shnum, just in case
	memset(s, 0, 80);
	if ((len = readall(fd, s, sizeof(toybuf)-8))<0) perror_msg_raw(name);

	if (!len) xputs("empty");
	// 45 bytes: https://www.muppetlabs.com/~breadbox/software/tiny/teensy.html
	else if (len>=45 && strstart(&s, "\177ELF")) do_elf_file(fd);
	else if (strstart(&s, "!<arch>\n")) xputs("ar archive");
	else if (*s=='%' && 2==sscanf(s, "%%PDF%d.%u", &ii, &magic))
	xprintf("PDF document, version %d.%u\n", -ii, magic);
	else if (len>28 && strstart(&s, "\x89PNG\x0d\x0a\x1a\x0a")) {
	// PNG is big-endian: https://www.w3.org/TR/PNG/#7Integers-and-byte-order
	int chunk_length = peek_be(s, 4);

	xprintf("PNG image data");

	// The IHDR chunk comes first: https://www.w3.org/TR/PNG/#11IHDR
	s += 4;
	if (chunk_length == 13 && strstart(&s, "IHDR")) {
	// https://www.w3.org/TR/PNG/#6Colour-values
	char c = 0, colors[] = {"grayscale", 0, "color RGB", "indexed color",
	"grayscale with alpha", 0, "color RGBA"};

	if (s[9]<ARRAY_LEN(colors)) c = colors[s[9]];
	xprintf(", %d x %d, %d-bit/%s, %sinterlaced", (int)peek_be(s, 4),
	(int)peek_be(s+4, 4), s[8], c ? : "unknown", s[12] ? "" : "non-");
	}

	xputc('\n');

	// https://www.w3.org/Graphics/GIF/spec-gif89a.txt
	} else if (len>16 && (strstart(&s, "GIF87a") \|\| strstart(&s, "GIF89a")))
	xprintf("GIF image data, version %3.3s, %d x %d\n",
	s-3, (int)peek_le(s, 2), (int)peek_le(s+2, 2));

	// https://en.wikipedia.org/wiki/JPEG#Syntax_and_structure
	else if (len>32 && !smemcmp(s, "\xff\xd8", 2)) {
	char *types[] = {"baseline", "extended sequential", "progressive"};
	int marker;

	printf("JPEG image data");
	while (s < toybuf+len-8) { // TODO: refill for files with lots of EXIF data?
	marker = peek_be(s, 2);
	if (marker >= 0xffd0 && marker <= 0xffd9) s += 2; // No data.
	else if (marker >= 0xffc0 && marker <= 0xffc2) {
	xprintf(", %s, %dx%d", types[marker-0xffc0], (int) peek_be(s+7, 2),
	(int) peek_be(s+5, 2));
	break;
	} else s += peek_be(s + 2, 2) + 2;
	}
	xputc('\n');

	} else if (len>8 && strstart(&s, "\xca\xfe\xba\xbe")) {
	unsigned count = peek_be(s, 4), i, arch;

	// 0xcafebabe can be a Java class file or a Mach-O universal binary.
	// Java major version numbers start with 0x2d for JDK 1.1, and realistically
	// you're never going to see more than 2 architectures in a binary anyway...
	if (count<0x2d && len>=(count*20)) {
	// https://eclecticlight.co/2020/07/28/universal-binaries-inside-fat-headers/
	xprintf("Mach-O universal binary with %u architecture%s:",
	count, count == 1 ? "" : "s");
	for (i = 0, s += 4; i < count; i++, s += 20) {
	arch = peek_be(s, 4);
	if (arch == 0x00000007) name = "i386";
	else if (arch == 0x01000007) name = "x86_64";
	else if (arch == 0x0000000c) name = "arm";
	else if (arch == 0x0100000c) name = "arm64";
	else name = "unknown";
	xprintf(" [%s]", name);
	}
	xprintf("\n");
	} else {
	// https://en.wikipedia.org/wiki/Java_class_file#General_layout
	xprintf("Java class file, version %d.%d (Java 1.%d)\n",
	(int)peek_be(s+2, 2), (int)peek_be(s, 2), (int)peek_be(s+2, 2)-44);
	}

	// https://source.android.com/devices/tech/dalvik/dex-format#dex-file-magic
	} else if (len>8 && strstart(&s, "dex\n") && !s[3])
	xprintf("Android dex file, version %s\n", s);

	// https://people.freebsd.org/~kientzle/libarchive/man/cpio.5.txt
	// the lengths for cpio are size of header + 9 bytes, since any valid
	// cpio archive ends with a record for "TARGET!!!"
	else if (len>6 && strstart(&s, "07070")) {
	char *cpioformat = "unknown type";

	if (*s == '7') cpioformat = "pre-SVR4 or odc";
	else if (*s == '1') cpioformat = "SVR4 with no CRC";
	else if (*s == '2') cpioformat = "SVR4 with CRC";
	xprintf("ASCII cpio archive (%s)\n", cpioformat);
	} else if (len>33 && ((magic=peek(&s,2))==0143561 \|\| magic==070707)) {
	if (magic == 0143561) printf("byte-swapped ");
	xputs("cpio archive");
	// tar archive (old, ustar/pax, or gnu)
	} else if (len>500 && is_tar_header(s))
	xprintf("%s tar archive%s\n", s[257] ? "POSIX" : "old",
	(s[262]!=' ' \|\| s[263]!=' ')?"":" (GNU)");
	// zip/jar/apk archive, ODF/OOXML document, or such
	else if (len>5 && strstart(&s, "PK\03\04")) {
	xprintf("Zip archive data");
	if (s) xprintf(", requires at least v%d.%d to extract", s/10, *s%10);
	xputc('\n');
	} else if (len>9 && strstart(&s, "7z\xbc\xaf\x27\x1c")) {
	xprintf("7-zip archive data");
	if (s \|\| s[1]) xprintf(", version %d.%d", s, s[1]);
	xputc('\n');
	} else if (len>4 && strstart(&s, "BZh") && isdigit(*s))
	xprintf("bzip2 compressed data, block size = %c00k\n", *s);
	else if (len>31 && peek_be(s, 7) == 0xfd377a585a0000ULL)
	xputs("xz compressed data");
	else if (len>10 && strstart(&s, "\x1f\x8b")) xputs("gzip compressed data");
	else if (len>32 && !smemcmp(s+1, "\xfa\xed\xfe", 3)) {
	int bit = (*s==0xce) ? 32 : 64;
	char *what = 0;

	xprintf("Mach-O %d-bit ", bit);

	if (s[4] == 7) what = (bit==32)?"x86":"x86-";
	else if (s[4] == 12) what = "arm";
	else if (s[4] == 18) what = "ppc";
	if (what) xprintf("%s%s ", what, (bit==32)?"":"64");
	else xprintf("(bad arch %d) ", s[4]);

	if (s[12] == 1) what = "object";
	else if (s[12] == 2) what = "executable";
	else if (s[12] == 6) what = "shared library";
	else what = NULL;
	if (what) xprintf("%s\n", what);
	else xprintf("(bad type %d)\n", s[9]);
	} else if (len>36 && !smemcmp(s, "OggS\x00\x02", 6)) {
	xprintf("Ogg data");
	// https://wiki.xiph.org/MIMETypesCodecs
	if (!smemcmp(s+28, "CELT ", 8)) xprintf(", celt audio");
	else if (!smemcmp(s+28, "CMML ", 8)) xprintf(", cmml text");
	else if (!smemcmp(s+28, "BBCD", 5)) xprintf(", dirac video");
	else if (!smemcmp(s+28, "\177FLAC", 5)) xprintf(", flac audio");
	else if (!smemcmp(s+28, "\x8bJNG\r\n\x1a\n", 8)) xprintf(", jng video");
	else if (!smemcmp(s+28, "\x80kate\0\0", 8)) xprintf(", kate text");
	else if (!smemcmp(s+28, "OggMIDI", 8)) xprintf(", midi text");
	else if (!smemcmp(s+28, "\x8aMNG\r\n\x1a\n", 8)) xprintf(", mng video");
	else if (!smemcmp(s+28, "OpusHead", 8)) xprintf(", opus audio");
	else if (!smemcmp(s+28, "PCM ", 8)) xprintf(", pcm audio");
	else if (!smemcmp(s+28, "\x89PNG\r\n\x1a\n", 8)) xprintf(", png video");
	else if (!smemcmp(s+28, "Speex ", 8)) xprintf(", speex audio");
	else if (!smemcmp(s+28, "\x80theora", 7)) xprintf(", theora video");
	else if (!smemcmp(s+28, "\x01vorbis", 7)) xprintf(", vorbis audio");
	else if (!smemcmp(s+28, "YUV4MPEG", 8)) xprintf(", yuv4mpeg video");
	xputc('\n');
	} else if (len>32 && !smemcmp(s, "RIF", 3) && !smemcmp(s+8, "WAVEfmt ", 8)) {
	// https://en.wikipedia.org/wiki/WAV
	int le = (s[3] == 'F');
	int format = le ? peek_le(s+20, 2) : peek_be(s+20, 2);
	int channels = le ? peek_le(s+22, 2) : peek_be(s+22, 2);
	int hz = le ? peek_le(s+24, 4) : peek_be(s+24, 4);
	int bits = le ? peek_le(s+34, 2) : peek_be(s+34, 2);

	xprintf("WAV audio, %s, ", le ? "LE" : "BE");
	if (bits) xprintf("%d-bit, ", bits);
	if (channels==1\|\|channels==2) xprintf("%s, ",(channels==1)?"mono":"stereo");
	else xprintf("%d-channel, ", channels);
	xprintf("%d Hz, ", hz);
	// See https://tools.ietf.org/html/rfc2361, though there appear to be bugs
	// in the RFC. This assumes wikipedia's example files are more correct.
	if (format == 0x01) xprintf("PCM");
	else if (format == 0x03) xprintf("IEEE float");
	else if (format == 0x06) xprintf("A-law");
	else if (format == 0x07) xprintf("µ-law");
	else if (format == 0x11) xprintf("ADPCM");
	else if (format == 0x22) xprintf("Truespeech");
	else if (format == 0x31) xprintf("GSM");
	else if (format == 0x55) xprintf("MP3");
	else if (format == 0x70) xprintf("CELP");
	else if (format == 0xfffe) xprintf("extensible");
	else xprintf("unknown format %d", format);
	xputc('\n');
	} else if (len>12 && peek_be(s, 4)==0x10000) xputs("TrueType font");
	else if (len>12 && !smemcmp(s, "ttcf", 5)) {
	xprintf("TrueType font collection, version %d, %d fonts\n",
	(int)peek_be(s+4, 2), (int)peek_be(s+8, 4));

	// https://docs.microsoft.com/en-us/typography/opentype/spec/otff
	} else if (len>12 && strstart(&s, "OTTO")) xputs("OpenType font");
	else if (strstart(&s, "BC\xc0\xde")) xputs("LLVM IR bitcode");
	else if (strstart(&s,"-----BEGIN CERTIFICATE-----")) xputs("PEM certificate");

	// https://msdn.microsoft.com/en-us/library/windows/desktop/ms680547(v=vs.85).aspx
	else if (len>0x70 && !smemcmp(s, "MZ", 2) &&
	(magic=peek_le(s+0x3c,4))<len-4 && !smemcmp(s+magic, "\x50\x45\0", 4)) {

	// Linux kernel images look like PE files.
	// https://www.kernel.org/doc/Documentation/arm64/booting.txt
	// I've only ever seen LE, 4KiB pages, so ignore flags for now.
	if (!smemcmp(s+0x38, "ARMd", 4)) return xputs("Linux arm64 kernel image");
	else if (!smemcmp(s+0x202, "HdrS", 4)) {
	// https://www.kernel.org/doc/Documentation/x86/boot.txt
	unsigned ver_off = peek_le(s+0x20e, 2);

	xprintf("Linux x86-64 kernel image");
	if ((0x200 + ver_off) < len) {
	s += 0x200 + ver_off;
	} else {
	if (lseek(fd, ver_off - len + 0x200, SEEK_CUR)<0 \|\|
	(len = readall(fd, s, sizeof(toybuf)))<0)
	return perror_msg_raw(name);
	}
	xprintf(", version %s\n", s);
	return;
	}

	xprintf("MS PE32%s executable %s", (peek_le(s+magic+24, 2)==0x20b)?"+":"",
	(peek_le(s+magic+22, 2)&0x2000)?"(DLL) ":"");
	if (peek_le(s+magic+20, 2)>70) {
	char *types[] = {0, "native", "GUI", "console", "OS/2", "driver", "CE",
	"EFI", "EFI boot", "EFI runtime", "EFI ROM", "XBOX", 0, "boot"}, *nn;
	unsigned type = peek_le(s+magic+92, 2);

	nn = (type<ARRAY_LEN(types)) ? types[type] : 0;
	xprintf("(%s) ", nn ? : "unknown");
	}
	xprintf("x86%s\n", (peek_le(s+magic+4, 2)==0x14c) ? "" : "-64");

	// https://en.wikipedia.org/wiki/BMP_file_format
	} else if (len>0x32 && !smemcmp(s, "BM", 2) && !peek_be(s+6, 4)) {
	xprintf("BMP image, %d x %d, %d bpp\n", (int)peek_le(s+18, 4),
	(int)peek_le(s+22,4), (int)peek_le(s+28, 2));

	// https://github.com/torvalds/linux/blob/master/tools/perf/Documentation/perf.data-file-format.txt
	} else if (len>=104 && strstart(&s, "PERFILE2")) xputs("Linux perf data");

	// https://android.googlesource.com/platform/system/core/+/master/libsparse/sparse_format.h
	else if (len>28 && peek_le(s, 4) == 0xed26ff3a) {
	xprintf("Android sparse image v%d.%d, %d %d-byte blocks (%d chunks)\n",
	(int)peek_le(s+4, 2), (int)peek_le(s+6, 2), (int)peek_le(s+16, 4),
	(int)peek_le(s+12, 4), (int)peek_le(s+20, 4));

	// https://android.googlesource.com/platform/system/tools/mkbootimg/+/refs/heads/master/include/bootimg/bootimg.h
	} else if (len>1632 && !smemcmp(s, "ANDROID!", 8)) {
	xprintf("Android boot image v%d\n", (int)peek_le(s+40, 4));

	// https://source.android.com/devices/architecture/dto/partitions
	} else if (len>32 && peek_be(s, 4) == 0xd7b7ab1e) {
	xprintf("Android DTB/DTBO v%d, %d entries\n", (int)peek_be(s+28, 4),
	(int)peek_be(s+16, 4));

	// frameworks/base/core/java/com/android/internal/util/BinaryXmlSerializer.java
	} else if (len>4 && !smemcmp(s, "ABX", 3)) {
	xprintf("Android Binary XML v%d\n", s[3]);

	// https://webassembly.github.io/spec/core/binary/modules.html#binary-module
	} else if (len>8 && !smemcmp(s, "\0asm", 4)) {
	xprintf("wasm binary module version %d\n", (int)peek_le(s+4, 4));

	// Text files, including shell scripts.
	} else {
	char *what = 0;
	int i, bytes;

	// If shell script, report which interpreter
	if (len>3 && strstart(&s, "#!")) {
	// Whitespace is allowed between the #! and the interpreter
	while (isspace(*s)) s++;
	if (strstart(&s, "/usr/bin/env")) while (isspace(*s)) s++;
	for (what = s; s && !isspace(s); s++);
	strcpy(s, " script");

	// Distinguish ASCII text, UTF-8 text, or data
	} else for (i = 0; i<len; ++i) {
	if (!(isprint(s[i]) \|\| isspace(s[i]))) {
	unsigned wc;

	if ((bytes = utf8towc(&wc, s+i, len-i))>0 && wcwidth(wc)>=0) {
	i += bytes-1;
	if (!what) what = "UTF-8 text";
	} else {
	what = "data";
	break;
	}
	}
	}
	xputs(what ? what : "ASCII text");
	}
	}

	void file_main(void)
	{
	char **arg;

	for (arg = toys.optargs; *arg; ++arg)
	TT.max_name_len = maxof(strlen(*arg), TT.max_name_len);

	// Can't use loopfiles here because it doesn't call function when can't open
	for (arg = toys.optargs; *arg; arg++) {
	char name = arg, *what = "unknown";
	struct stat sb;
	int fd = !strcmp(name, "-");

	if (!FLAG(b))
	xprintf("%s: %*s", name, (int)(TT.max_name_len - strlen(name)), "");

	sb.st_size = 0;
	if (!fd && (FLAG(L) ? stat : lstat)(name, &sb)) {
	xprintf("cannot open: %s\n", strerror(errno));

	continue;
	}

	if (!fd && !FLAG(s) && (S_ISBLK(sb.st_mode) \|\| S_ISCHR(sb.st_mode))) {
	sprintf(what = toybuf, "%s special (%u/%u)",
	S_ISBLK(sb.st_mode) ? "block" : "character",
	dev_major(sb.st_rdev), dev_minor(sb.st_rdev));
	} else if (fd \|\| S_ISREG(sb.st_mode)) {
	TT.len = sb.st_size;
	// This test identifies an empty file we don't have permission to read
	if (!fd && !sb.st_size) what = "empty";
	else if ((fd = openro(name, O_RDONLY)) != -1) {
	do_regular_file(fd, name);
	if (fd) close(fd);

	continue;
	}
	} else if (S_ISFIFO(sb.st_mode)) what = "fifo";
	else if (S_ISDIR(sb.st_mode)) what = "directory";
	else if (S_ISSOCK(sb.st_mode)) what = "socket";
	else if (S_ISLNK(sb.st_mode)) {
	char *lnk = xreadlink(name);

	sprintf(what = toybuf, "%ssymbolic link to %s",
	stat(name, &sb) ? "broken " : "", lnk);
	free(lnk);
	}
	xputs(what);
	}
	}