4.3BSD - /usr/src/usr.bin/file.c

   1: #ifndef lint
   2: static  char sccsid[] = "@(#)file.c	4.12 (Berkeley) 11/17/85";
   3: #endif
   4: /*
   5:  * file - determine type of file
   6:  */
   7: 
   8: #include <sys/param.h>
   9: #include <sys/stat.h>
  10: #include <stdio.h>
  11: #include <ctype.h>
  12: #include <a.out.h>
  13: int errno;
  14: int sys_nerr;
  15: char    *sys_errlist[];
  16: int in;
  17: int i  = 0;
  18: char buf[BUFSIZ];
  19: char *troff[] = {   /* new troff intermediate lang */
  20:     "x","T","res","init","font","202","V0","p1",0};
  21: char *fort[] = {
  22:     "function","subroutine","common","dimension","block","integer",
  23:     "real","data","double",0};
  24: char *asc[] = {
  25:     "chmk","mov","tst","clr","jmp",0};
  26: char *c[] = {
  27:     "int","char","float","double","struct","extern",0};
  28: char *as[] = {
  29:     "globl","byte","align","text","data","comm",0};
  30: char *sh[] = {
  31:     "fi", "elif", "esac", "done", "export",
  32:     "readonly", "trap", "PATH", "HOME", 0 };
  33: char *csh[] = {
  34:     "alias", "breaksw", "endsw", "foreach", "limit",  "onintr",
  35:     "repeat", "setenv", "source", "path", "home", 0 };
  36: int ifile;
  37: 
  38: main(argc, argv)
  39: char **argv;
  40: {
  41:     FILE *fl;
  42:     register char *p;
  43:     char ap[MAXPATHLEN + 1];
  44:     extern char _sobuf[];
  45: 
  46:     if (argc < 2) {
  47:         fprintf(stderr, "usage: %s file ...\n", argv[0]);
  48:         exit(3);
  49:     }
  50: 
  51:     if (argc>1 && argv[1][0]=='-' && argv[1][1]=='f') {
  52:         if ((fl = fopen(argv[2], "r")) == NULL) {
  53:             perror(argv[2]);
  54:             exit(2);
  55:         }
  56:         while ((p = fgets(ap, sizeof ap, fl)) != NULL) {
  57:             int l = strlen(p);
  58:             if (l>0)
  59:                 p[l-1] = '\0';
  60:             printf("%s:	", p);
  61:             type(p);
  62:             if (ifile>=0)
  63:                 close(ifile);
  64:         }
  65:         exit(1);
  66:     }
  67:     while(argc > 1) {
  68:         printf("%s:	", argv[1]);
  69:         type(argv[1]);
  70:         fflush(stdout);
  71:         argc--;
  72:         argv++;
  73:         if (ifile >= 0)
  74:             close(ifile);
  75:     }
  76:     exit(0);
  77: }
  78: 
  79: type(file)
  80: char *file;
  81: {
  82:     int j,nl;
  83:     char ch;
  84:     struct stat mbuf;
  85:     char slink[MAXPATHLEN + 1];
  86: 
  87:     ifile = -1;
  88:     if (lstat(file, &mbuf) < 0) {
  89:         printf("%s\n",
  90:         (unsigned)errno < sys_nerr? sys_errlist[errno]: "Cannot stat");
  91:         return;
  92:     }
  93:     switch (mbuf.st_mode & S_IFMT) {
  94: 
  95:     case S_IFLNK:
  96:         printf("symbolic link");
  97:         j = readlink(file, slink, sizeof slink - 1);
  98:         if (j >= 0) {
  99:             slink[j] = '\0';
 100:             printf(" to %s", slink);
 101:         }
 102:         printf("\n");
 103:         return;
 104: 
 105:     case S_IFDIR:
 106:         if (mbuf.st_mode & S_ISVTX)
 107:             printf("append-only ");
 108:         printf("directory\n");
 109:         return;
 110: 
 111:     case S_IFCHR:
 112:     case S_IFBLK:
 113:         printf("%s special (%d/%d)\n",
 114:             (mbuf.st_mode&S_IFMT) == S_IFCHR ? "character" : "block",
 115:              major(mbuf.st_rdev), minor(mbuf.st_rdev));
 116:         return;
 117: 
 118:     case S_IFSOCK:
 119:         printf("socket\n");
 120:         return;
 121:     }
 122: 
 123:     ifile = open(file, 0);
 124:     if(ifile < 0) {
 125:         printf("%s\n",
 126:         (unsigned)errno < sys_nerr? sys_errlist[errno]: "Cannot read");
 127:         return;
 128:     }
 129:     in = read(ifile, buf, BUFSIZ);
 130:     if(in == 0){
 131:         printf("empty\n");
 132:         return;
 133:     }
 134:     switch(*(int *)buf) {
 135: 
 136:     case 0413:
 137:         printf("demand paged ");
 138: 
 139:     case 0410:
 140:         printf("pure ");
 141:         goto exec;
 142: 
 143:     case 0411:
 144:         printf("jfr or pdp-11 unix 411 executable\n");
 145:         return;
 146: 
 147:     case 0407:
 148: exec:
 149:         if (mbuf.st_mode & S_ISUID)
 150:             printf("set-uid ");
 151:         if (mbuf.st_mode & S_ISGID)
 152:             printf("set-gid ");
 153:         if (mbuf.st_mode & S_ISVTX)
 154:             printf("sticky ");
 155:         printf("executable");
 156:         if(((int *)buf)[4] != 0) {
 157:             printf(" not stripped");
 158:             if(oldo(buf))
 159:                 printf(" (old format symbol table)");
 160:         }
 161:         printf("\n");
 162:         return;
 163: 
 164:     case 0177555:
 165:         printf("very old archive\n");
 166:         return;
 167: 
 168:     case 0177545:
 169:         printf("old archive\n");
 170:         return;
 171: 
 172:     case 070707:
 173:         printf("cpio data\n");
 174:         return;
 175:     }
 176: 
 177:     if (buf[0] == '#' && buf[1] == '!' && shellscript(buf+2, &mbuf))
 178:         return;
 179:     if (buf[0] == '\037' && buf[1] == '\235') {
 180:         if (buf[2]&0x80)
 181:             printf("block ");
 182:         printf("compressed %d bit code data\n", buf[2]&0x1f);
 183:         return;
 184:     }
 185:     if(strncmp(buf, "!<arch>\n__.SYMDEF", 17) == 0 ) {
 186:         printf("archive random library\n");
 187:         return;
 188:     }
 189:     if (strncmp(buf, "!<arch>\n", 8)==0) {
 190:         printf("archive\n");
 191:         return;
 192:     }
 193:     if (mbuf.st_size % 512 == 0) {  /* it may be a PRESS file */
 194:         lseek(ifile, -512L, 2); /* last block */
 195:         if (read(ifile, buf, BUFSIZ) > 0 && *(short *)buf == 12138) {
 196:             printf("PRESS file\n");
 197:             return;
 198:         }
 199:     }
 200:     i = 0;
 201:     if(ccom() == 0)goto notc;
 202:     while(buf[i] == '#'){
 203:         j = i;
 204:         while(buf[i++] != '\n'){
 205:             if(i - j > 255){
 206:                 printf("data\n");
 207:                 return;
 208:             }
 209:             if(i >= in)goto notc;
 210:         }
 211:         if(ccom() == 0)goto notc;
 212:     }
 213: check:
 214:     if(lookup(c) == 1){
 215:         while((ch = buf[i++]) != ';' && ch != '{')if(i >= in)goto notc;
 216:         printf("c program text");
 217:         goto outa;
 218:     }
 219:     nl = 0;
 220:     while(buf[i] != '('){
 221:         if(buf[i] <= 0)
 222:             goto notas;
 223:         if(buf[i] == ';'){
 224:             i++;
 225:             goto check;
 226:         }
 227:         if(buf[i++] == '\n')
 228:             if(nl++ > 6)goto notc;
 229:         if(i >= in)goto notc;
 230:     }
 231:     while(buf[i] != ')'){
 232:         if(buf[i++] == '\n')
 233:             if(nl++ > 6)goto notc;
 234:         if(i >= in)goto notc;
 235:     }
 236:     while(buf[i] != '{'){
 237:         if(buf[i++] == '\n')
 238:             if(nl++ > 6)goto notc;
 239:         if(i >= in)goto notc;
 240:     }
 241:     printf("c program text");
 242:     goto outa;
 243: notc:
 244:     i = 0;
 245:     while(buf[i] == 'c' || buf[i] == '#'){
 246:         while(buf[i++] != '\n')if(i >= in)goto notfort;
 247:     }
 248:     if(lookup(fort) == 1){
 249:         printf("fortran program text");
 250:         goto outa;
 251:     }
 252: notfort:
 253:     i=0;
 254:     if(ascom() == 0)goto notas;
 255:     j = i-1;
 256:     if(buf[i] == '.'){
 257:         i++;
 258:         if(lookup(as) == 1){
 259:             printf("assembler program text");
 260:             goto outa;
 261:         }
 262:         else if(buf[j] == '\n' && isalpha(buf[j+2])){
 263:             printf("roff, nroff, or eqn input text");
 264:             goto outa;
 265:         }
 266:     }
 267:     while(lookup(asc) == 0){
 268:         if(ascom() == 0)goto notas;
 269:         while(buf[i] != '\n' && buf[i++] != ':')
 270:             if(i >= in)goto notas;
 271:         while(buf[i] == '\n' || buf[i] == ' ' || buf[i] == '\t')if(i++ >= in)goto notas;
 272:         j = i-1;
 273:         if(buf[i] == '.'){
 274:             i++;
 275:             if(lookup(as) == 1){
 276:                 printf("assembler program text");
 277:                 goto outa;
 278:             }
 279:             else if(buf[j] == '\n' && isalpha(buf[j+2])){
 280:                 printf("roff, nroff, or eqn input text");
 281:                 goto outa;
 282:             }
 283:         }
 284:     }
 285:     printf("assembler program text");
 286:     goto outa;
 287: notas:
 288:     for(i=0; i < in; i++)if(buf[i]&0200){
 289:         if (buf[0]=='\100' && buf[1]=='\357')
 290:             printf("troff (CAT) output\n");
 291:         else
 292:             printf("data\n");
 293:         return;
 294:     }
 295:     if (mbuf.st_mode&((S_IEXEC)|(S_IEXEC>>3)|(S_IEXEC>>6))) {
 296:         if (mbuf.st_mode & S_ISUID)
 297:             printf("set-uid ");
 298:         if (mbuf.st_mode & S_ISGID)
 299:             printf("set-gid ");
 300:         if (mbuf.st_mode & S_ISVTX)
 301:             printf("sticky ");
 302:         if (shell(buf, in, sh))
 303:             printf("shell script");
 304:         else if (shell(buf, in, csh))
 305:             printf("c-shell script");
 306:         else
 307:             printf("commands text");
 308:     } else if (troffint(buf, in))
 309:         printf("troff intermediate output text");
 310:     else if (shell(buf, in, sh))
 311:         printf("shell commands");
 312:     else if (shell(buf, in, csh))
 313:         printf("c-shell commands");
 314:     else if (english(buf, in))
 315:         printf("English text");
 316:     else
 317:         printf("ascii text");
 318: outa:
 319:     while(i < in)
 320:         if((buf[i++]&0377) > 127){
 321:             printf(" with garbage\n");
 322:             return;
 323:         }
 324:     /* if next few lines in then read whole file looking for nulls ...
 325: 		while((in = read(ifile,buf,BUFSIZ)) > 0)
 326: 			for(i = 0; i < in; i++)
 327: 				if((buf[i]&0377) > 127){
 328: 					printf(" with garbage\n");
 329: 					return;
 330: 				}
 331: 		/*.... */
 332:     printf("\n");
 333: }
 334: 
 335: oldo(cp)
 336: char *cp;
 337: {
 338:     struct exec ex;
 339:     struct stat stb;
 340: 
 341:     ex = *(struct exec *)cp;
 342:     if (fstat(ifile, &stb) < 0)
 343:         return(0);
 344:     if (N_STROFF(ex)+sizeof(off_t) > stb.st_size)
 345:         return (1);
 346:     return (0);
 347: }
 348: 
 349: 
 350: 
 351: troffint(bp, n)
 352: char *bp;
 353: int n;
 354: {
 355:     int k;
 356: 
 357:     i = 0;
 358:     for (k = 0; k < 6; k++) {
 359:         if (lookup(troff) == 0)
 360:             return(0);
 361:         if (lookup(troff) == 0)
 362:             return(0);
 363:         while (i < n && buf[i] != '\n')
 364:             i++;
 365:         if (i++ >= n)
 366:             return(0);
 367:     }
 368:     return(1);
 369: }
 370: lookup(tab)
 371: char *tab[];
 372: {
 373:     char r;
 374:     int k,j,l;
 375:     while(buf[i] == ' ' || buf[i] == '\t' || buf[i] == '\n')i++;
 376:     for(j=0; tab[j] != 0; j++){
 377:         l=0;
 378:         for(k=i; ((r=tab[j][l++]) == buf[k] && r != '\0');k++);
 379:         if(r == '\0')
 380:             if(buf[k] == ' ' || buf[k] == '\n' || buf[k] == '\t'
 381:                 || buf[k] == '{' || buf[k] == '/'){
 382:                 i=k;
 383:                 return(1);
 384:             }
 385:     }
 386:     return(0);
 387: }
 388: ccom(){
 389:     char cc;
 390:     while((cc = buf[i]) == ' ' || cc == '\t' || cc == '\n')if(i++ >= in)return(0);
 391:     if(buf[i] == '/' && buf[i+1] == '*'){
 392:         i += 2;
 393:         while(buf[i] != '*' || buf[i+1] != '/'){
 394:             if(buf[i] == '\\')i += 2;
 395:             else i++;
 396:             if(i >= in)return(0);
 397:         }
 398:         if((i += 2) >= in)return(0);
 399:     }
 400:     if(buf[i] == '\n')if(ccom() == 0)return(0);
 401:     return(1);
 402: }
 403: ascom(){
 404:     while(buf[i] == '/'){
 405:         i++;
 406:         while(buf[i++] != '\n')if(i >= in)return(0);
 407:         while(buf[i] == '\n')if(i++ >= in)return(0);
 408:     }
 409:     return(1);
 410: }
 411: 
 412: english (bp, n)
 413: char *bp;
 414: {
 415: # define NASC 128
 416:     int ct[NASC], j, vow, freq, rare;
 417:     int badpun = 0, punct = 0;
 418:     if (n<50) return(0); /* no point in statistics on squibs */
 419:     for(j=0; j<NASC; j++)
 420:         ct[j]=0;
 421:     for(j=0; j<n; j++)
 422:     {
 423:         if (bp[j]<NASC)
 424:             ct[bp[j]|040]++;
 425:         switch (bp[j])
 426:         {
 427:         case '.':
 428:         case ',':
 429:         case ')':
 430:         case '%':
 431:         case ';':
 432:         case ':':
 433:         case '?':
 434:             punct++;
 435:             if ( j < n-1 &&
 436:                 bp[j+1] != ' ' &&
 437:                 bp[j+1] != '\n')
 438:                 badpun++;
 439:         }
 440:     }
 441:     if (badpun*5 > punct)
 442:         return(0);
 443:     vow = ct['a'] + ct['e'] + ct['i'] + ct['o'] + ct['u'];
 444:     freq = ct['e'] + ct['t'] + ct['a'] + ct['i'] + ct['o'] + ct['n'];
 445:     rare = ct['v'] + ct['j'] + ct['k'] + ct['q'] + ct['x'] + ct['z'];
 446:     if (2*ct[';'] > ct['e']) return(0);
 447:     if ( (ct['>']+ct['<']+ct['/'])>ct['e']) return(0); /* shell file test */
 448:     return (vow*5 >= n-ct[' '] && freq >= 10*rare);
 449: }
 450: 
 451: shellscript(buf, sb)
 452:     char buf[];
 453:     struct stat *sb;
 454: {
 455:     register char *tp;
 456:     char *cp, *xp, *index();
 457: 
 458:     cp = index(buf, '\n');
 459:     if (cp == 0 || cp - buf > in)
 460:         return (0);
 461:     for (tp = buf; tp != cp && isspace(*tp); tp++)
 462:         if (!isascii(*tp))
 463:             return (0);
 464:     for (xp = tp; tp != cp && !isspace(*tp); tp++)
 465:         if (!isascii(*tp))
 466:             return (0);
 467:     if (tp == xp)
 468:         return (0);
 469:     if (sb->st_mode & S_ISUID)
 470:         printf("set-uid ");
 471:     if (sb->st_mode & S_ISGID)
 472:         printf("set-gid ");
 473:     if (strncmp(xp, "/bin/sh", tp-xp) == 0)
 474:         xp = "shell";
 475:     else if (strncmp(xp, "/bin/csh", tp-xp) == 0)
 476:         xp = "c-shell";
 477:     else
 478:         *tp = '\0';
 479:     printf("executable %s script\n", xp);
 480:     return (1);
 481: }
 482: 
 483: shell(bp, n, tab)
 484:     char *bp;
 485:     int n;
 486:     char *tab[];
 487: {
 488: 
 489:     i = 0;
 490:     do {
 491:         if (buf[i] == '#' || buf[i] == ':')
 492:             while (i < n && buf[i] != '\n')
 493:                 i++;
 494:         if (++i >= n)
 495:             break;
 496:         if (lookup(tab) == 1)
 497:             return (1);
 498:     } while (i < n);
 499:     return (0);
 500: }

Defined functions

Defined variables

Defined macros