sys_errlist -> strerror(3)

[unix-history] / usr / src / usr.bin / file / file.c

#ifndef lint
static  char sccsid[] = "@(#)file.c     4.16 (Berkeley) %G%";
#endif
/*
* file - determine type of file
*/

#include <sys/param.h>
#include <sys/stat.h>
#include <string.h>
#include <stdio.h>
#include <ctype.h>
#include <a.out.h>

extern int      errno;

int in;
int i  = 0;
char buf[BUFSIZ];
char *troff[] = {       /* new troff intermediate lang */
       "x","T","res","init","font","202","V0","p1",0};
char *fort[] = {
       "function","subroutine","common","dimension","block","integer",
       "real","data","double",0};
char *asc[] = {
       "chmk","mov","tst","clr","jmp",0};
char *c[] = {
       "int","char","float","double","struct","extern",0};
char *as[] = {
       "globl","byte","align","text","data","comm",0};
char *sh[] = {
       "fi", "elif", "esac", "done", "export",
       "readonly", "trap", "PATH", "HOME", 0 };
char *csh[] = {
       "alias", "breaksw", "endsw", "foreach", "limit",  "onintr",
       "repeat", "setenv", "source", "path", "home", 0 };
int     ifile;

main(argc, argv)
char **argv;
{
       FILE *fl;
       register char *p;
       char ap[MAXPATHLEN + 1];

       if (argc < 2) {
               fprintf(stderr, "usage: %s file ...\n", argv[0]);
               exit(3);
       }
               
       if (argc>1 && argv[1][0]=='-' && argv[1][1]=='f') {
               if ((fl = fopen(argv[2], "r")) == NULL) {
                       perror(argv[2]);
                       exit(2);
               }
               while ((p = fgets(ap, sizeof ap, fl)) != NULL) {
                       int l = strlen(p);
                       if (l>0)
                               p[l-1] = '\0';
                       printf("%s:     ", p);
                       type(p);
                       if (ifile>=0)
                               close(ifile);
               }
               exit(1);
       }
       while(argc > 1) {
               printf("%s:     ", argv[1]);
               type(argv[1]);
               fflush(stdout);
               argc--;
               argv++;
               if (ifile >= 0)
                       close(ifile);
       }
       exit(0);
}

type(file)
char *file;
{
       int j,nl;
       char ch;
       struct stat mbuf;
       char slink[MAXPATHLEN + 1];

       ifile = -1;
       if (lstat(file, &mbuf) < 0) {
               fprintf(stderr, "file: %s: %s\n", file, strerror(errno));
               return;
       }
       switch (mbuf.st_mode & S_IFMT) {

       case S_IFLNK:
               printf("symbolic link");
               j = readlink(file, slink, sizeof slink - 1);
               if (j >= 0) {
                       slink[j] = '\0';
                       printf(" to %s", slink);
               }
               printf("\n");
               return;

       case S_IFDIR:
               if (mbuf.st_mode & S_ISVTX)
                       printf("append-only ");
               printf("directory\n");
               return;

       case S_IFCHR:
       case S_IFBLK:
               printf("%s special (%d/%d)\n",
                   (mbuf.st_mode&S_IFMT) == S_IFCHR ? "character" : "block",
                    major(mbuf.st_rdev), minor(mbuf.st_rdev));
               return;

       case S_IFSOCK:
               printf("socket\n");
               return;
       }

       ifile = open(file, 0);
       if(ifile < 0) {
               fprintf(stderr, "file: %s: %s\n", file, strerror(errno));
               return;
       }
       in = read(ifile, buf, BUFSIZ);
       if(in == 0){
               printf("empty\n");
               return;
       }
       switch(*(int *)buf) {

       case 0413:
               printf("demand paged ");

       case 0410:
               printf("pure ");
               goto exec;

       case 0411:
               printf("jfr or pdp-11 unix 411 executable\n");
               return;

       case 0407:
exec:
               if (mbuf.st_mode & S_ISUID)
                       printf("set-uid ");
               if (mbuf.st_mode & S_ISGID)
                       printf("set-gid ");
               if (mbuf.st_mode & S_ISVTX)
                       printf("sticky ");
               printf("executable");
               if(((int *)buf)[4] != 0) {
                       printf(" not stripped");
                       if(oldo(buf))
                               printf(" (old format symbol table)");
               }
               printf("\n");
               return;

       case 0177555:
               printf("very old archive\n");
               return;

       case 0177545:
               printf("old archive\n");
               return;

       case 070707:
               printf("cpio data\n");
               return;
       }

       if (buf[0] == '#' && buf[1] == '!' && shellscript(buf+2, &mbuf))
               return;
       if (buf[0] == '\037' && buf[1] == '\235') {
               if (buf[2]&0x80)
                       printf("block ");
               printf("compressed %d bit code data\n", buf[2]&0x1f);
               return;
       }
       if(strncmp(buf, "!<arch>\n__.SYMDEF", 17) == 0 ) {
               printf("archive random library\n");
               return;
       }
       if (strncmp(buf, "!<arch>\n", 8)==0) {
               printf("archive\n");
               return;
       }
       if (mbuf.st_size % 512 == 0) {  /* it may be a PRESS file */
               lseek(ifile, -512L, 2); /* last block */
               if (read(ifile, buf, BUFSIZ) > 0 && *(short *)buf == 12138) {
                       printf("PRESS file\n");
                       return;
               }
       }
       i = 0;
       if(ccom() == 0)goto notc;
       while(buf[i] == '#'){
               j = i;
               while(buf[i++] != '\n'){
                       if(i - j > 255){
                               printf("data\n"); 
                               return;
                       }
                       if(i >= in)goto notc;
               }
               if(ccom() == 0)goto notc;
       }
check:
       if(lookup(c) == 1){
               while((ch = buf[i++]) != ';' && ch != '{')if(i >= in)goto notc;
               printf("c program text");
               goto outa;
       }
       nl = 0;
       while(buf[i] != '('){
               if(buf[i] <= 0)
                       goto notas;
               if(buf[i] == ';'){
                       i++; 
                       goto check; 
               }
               if(buf[i++] == '\n')
                       if(nl++ > 6)goto notc;
               if(i >= in)goto notc;
       }
       while(buf[i] != ')'){
               if(buf[i++] == '\n')
                       if(nl++ > 6)goto notc;
               if(i >= in)goto notc;
       }
       while(buf[i] != '{'){
               if(buf[i++] == '\n')
                       if(nl++ > 6)goto notc;
               if(i >= in)goto notc;
       }
       printf("c program text");
       goto outa;
notc:
       i = 0;
       while(buf[i] == 'c' || buf[i] == '#'){
               while(buf[i++] != '\n')if(i >= in)goto notfort;
       }
       if(lookup(fort) == 1){
               printf("fortran program text");
               goto outa;
       }
notfort:
       i=0;
       if(ascom() == 0)goto notas;
       j = i-1;
       if(buf[i] == '.'){
               i++;
               if(lookup(as) == 1){
                       printf("assembler program text"); 
                       goto outa;
               }
               else if(buf[j] == '\n' && isalpha(buf[j+2])){
                       printf("roff, nroff, or eqn input text");
                       goto outa;
               }
       }
       while(lookup(asc) == 0){
               if(ascom() == 0)goto notas;
               while(buf[i] != '\n' && buf[i++] != ':')
                       if(i >= in)goto notas;
               while(buf[i] == '\n' || buf[i] == ' ' || buf[i] == '\t')if(i++ >= in)goto notas;
               j = i-1;
               if(buf[i] == '.'){
                       i++;
                       if(lookup(as) == 1){
                               printf("assembler program text"); 
                               goto outa; 
                       }
                       else if(buf[j] == '\n' && isalpha(buf[j+2])){
                               printf("roff, nroff, or eqn input text");
                               goto outa;
                       }
               }
       }
       printf("assembler program text");
       goto outa;
notas:
       for(i=0; i < in; i++)if(buf[i]&0200){
               if (buf[0]=='\100' && buf[1]=='\357')
                       printf("troff (CAT) output\n");
               else
                       printf("data\n"); 
               return;
       }
       if (mbuf.st_mode&((S_IEXEC)|(S_IEXEC>>3)|(S_IEXEC>>6))) {
               if (mbuf.st_mode & S_ISUID)
                       printf("set-uid ");
               if (mbuf.st_mode & S_ISGID)
                       printf("set-gid ");
               if (mbuf.st_mode & S_ISVTX)
                       printf("sticky ");
               if (shell(buf, in, sh))
                       printf("shell script");
               else if (shell(buf, in, csh))
                       printf("c-shell script");
               else
                       printf("commands text");
       } else if (troffint(buf, in))
               printf("troff intermediate output text");
       else if (shell(buf, in, sh))
               printf("shell commands");
       else if (shell(buf, in, csh))
               printf("c-shell commands");
       else if (english(buf, in))
               printf("English text");
       else
               printf("ascii text");
outa:
       while(i < in)
               if((buf[i++]&0377) > 127){
                       printf(" with garbage\n");
                       return;
               }
       /* if next few lines in then read whole file looking for nulls ...
               while((in = read(ifile,buf,BUFSIZ)) > 0)
                       for(i = 0; i < in; i++)
                               if((buf[i]&0377) > 127){
                                       printf(" with garbage\n");
                                       return;
                               }
               /*.... */
       printf("\n");
}

oldo(cp)
char *cp;
{
       struct exec ex;
       struct stat stb;

       ex = *(struct exec *)cp;
       if (fstat(ifile, &stb) < 0)
               return(0);
       if (N_STROFF(ex)+sizeof(off_t) > stb.st_size)
               return (1);
       return (0);
}



troffint(bp, n)
char *bp;
int n;
{
       int k;

       i = 0;
       for (k = 0; k < 6; k++) {
               if (lookup(troff) == 0)
                       return(0);
               if (lookup(troff) == 0)
                       return(0);
               while (i < n && buf[i] != '\n')
                       i++;
               if (i++ >= n)
                       return(0);
       }
       return(1);
}
lookup(tab)
char *tab[];
{
       char r;
       int k,j,l;
       while(buf[i] == ' ' || buf[i] == '\t' || buf[i] == '\n')i++;
       for(j=0; tab[j] != 0; j++){
               l=0;
               for(k=i; ((r=tab[j][l++]) == buf[k] && r != '\0');k++);
               if(r == '\0')
                       if(buf[k] == ' ' || buf[k] == '\n' || buf[k] == '\t'
                           || buf[k] == '{' || buf[k] == '/'){
                               i=k;
                               return(1);
                       }
       }
       return(0);
}
ccom(){
       char cc;
       while((cc = buf[i]) == ' ' || cc == '\t' || cc == '\n')if(i++ >= in)return(0);
       if(buf[i] == '/' && buf[i+1] == '*'){
               i += 2;
               while(buf[i] != '*' || buf[i+1] != '/'){
                       if(buf[i] == '\\')i += 2;
                       else i++;
                       if(i >= in)return(0);
               }
               if((i += 2) >= in)return(0);
       }
       if(buf[i] == '\n')if(ccom() == 0)return(0);
       return(1);
}
ascom(){
       while(buf[i] == '/'){
               i++;
               while(buf[i++] != '\n')if(i >= in)return(0);
               while(buf[i] == '\n')if(i++ >= in)return(0);
       }
       return(1);
}

english (bp, n)
char *bp;
{
# define NASC 128
       int ct[NASC], j, vow, freq, rare;
       int badpun = 0, punct = 0;
       if (n<50) return(0); /* no point in statistics on squibs */
       for(j=0; j<NASC; j++)
               ct[j]=0;
       for(j=0; j<n; j++)
       {
               if ((u_char)bp[j]<NASC)
                       ct[bp[j]|040]++;
               switch (bp[j])
               {
               case '.': 
               case ',': 
               case ')': 
               case '%':
               case ';': 
               case ':': 
               case '?':
                       punct++;
                       if ( j < n-1 &&
                           bp[j+1] != ' ' &&
                           bp[j+1] != '\n')
                               badpun++;
               }
       }
       if (badpun*5 > punct)
               return(0);
       vow = ct['a'] + ct['e'] + ct['i'] + ct['o'] + ct['u'];
       freq = ct['e'] + ct['t'] + ct['a'] + ct['i'] + ct['o'] + ct['n'];
       rare = ct['v'] + ct['j'] + ct['k'] + ct['q'] + ct['x'] + ct['z'];
       if (2*ct[';'] > ct['e']) return(0);
       if ( (ct['>']+ct['<']+ct['/'])>ct['e']) return(0); /* shell file test */
       return (vow*5 >= n-ct[' '] && freq >= 10*rare);
}

shellscript(buf, sb)
       char buf[];
       struct stat *sb;
{
       register char *tp;
       char *cp, *xp, *index();

       cp = index(buf, '\n');
       if (cp == 0 || cp - buf > in)
               return (0);
       for (tp = buf; tp != cp && isspace(*tp); tp++)
               if (!isascii(*tp))
                       return (0);
       for (xp = tp; tp != cp && !isspace(*tp); tp++)
               if (!isascii(*tp))
                       return (0);
       if (tp == xp)
               return (0);
       if (sb->st_mode & S_ISUID)
               printf("set-uid ");
       if (sb->st_mode & S_ISGID)
               printf("set-gid ");
       if (strncmp(xp, "/bin/sh", tp-xp) == 0)
               xp = "shell";
       else if (strncmp(xp, "/bin/csh", tp-xp) == 0)
               xp = "c-shell";
       else
               *tp = '\0';
       printf("executable %s script\n", xp);
       return (1);
}

shell(bp, n, tab)
       char *bp;
       int n;
       char *tab[];
{

       i = 0;
       do {
               if (buf[i] == '#' || buf[i] == ':')
                       while (i < n && buf[i] != '\n')
                               i++;
               if (++i >= n)
                       break;
               if (lookup(tab) == 1)
                       return (1);
       } while (i < n);
       return (0);
}