BSD 4_3_Tahoe release

[unix-history] / usr / src / ucb / strings.c

/*
* Copyright (c) 1980 Regents of the University of California.
* All rights reserved.  The Berkeley software License Agreement
* specifies the terms and conditions for redistribution.
*/

#ifndef lint
char copyright[] =
"@(#) Copyright (c) 1980 Regents of the University of California.\n\
All rights reserved.\n";
#endif not lint

#ifndef lint
static char sccsid[] = "@(#)strings.c   5.3 (Berkeley) 12/3/86";
#endif not lint

#include <sys/types.h>
#include <sys/file.h>
#include <a.out.h>
#include <stdio.h>
#include <ctype.h>

#define DEF_LEN         4               /* default minimum string length */
#define EOS             (char)NULL      /* end of string */
#define ERR             -1              /* general error */
#define ERREXIT         1               /* error exit */
#define NO              0               /* false/no */
#define OK              0               /* ok exit */
#define YES             1               /* true/yes */

#define ISSTR(ch)       (isascii(ch) && (isprint(ch) || ch == '\t'))

typedef struct exec     EXEC;           /* struct exec cast */

static long     foff;                   /* offset in the file */
static int      hcnt,                   /* head count */
               head_len,               /* length of header */
               read_len;               /* length to read */
static u_char   hbfr[sizeof(EXEC)];     /* buffer for struct exec */

main(argc,argv)
int     argc;
char    **argv;
{
       register int    ch,             /* character */
                       cnt;            /* general counter */
       register u_char *C;             /* bfr pointer */
       EXEC    *head;                  /* exec header pointer */
       int     minlen = DEF_LEN;       /* minimum string length */
       short   asdata = NO,            /* look in everything */
               oflg;                   /* print octal location */
       u_char  *bfr;                   /* collection buffer */
       char    *file,                  /* file name for error */
               *malloc();

       /*
        * for backward compatibility, allow '-' to specify 'a' flag; no
        * longer documented in the man page or usage string.
        */
       for (++argv;*argv && **argv ==  '-';++argv) {
               for (cnt = 1;(*argv)[cnt];++cnt)
                       switch ((*argv)[cnt]) {
                               case 'a':
                                       asdata = YES;
                                       break;
                               case 'o':
                                       oflg = YES;
                                       break;
                               default:        /* getopt message compatible */
                                       if (!isdigit((*argv)[cnt])) {
                                               fprintf(stderr,"strings: illegal option -- %c\nusage: strings [-ao] [-#] [file ... ]\n",(*argv)[cnt]);
                                               exit(ERREXIT);
                                       }
                                       minlen = atoi(*argv + 1);
                                       break;
                       }
               if (cnt == 1)
                       asdata = YES;
       }

       if (!(bfr = (u_char *)malloc((u_int)minlen))) {
               fputs("strings: unable to allocate space.\n",stderr);
               exit(ERREXIT);
       }
       bfr[minlen] = EOS;
       file = "stdin";
       do {
               if (*argv) {
                       if (!freopen(*argv,"r",stdin)) {
                               perror(*argv);
                               exit(ERREXIT);
                       }
                       file = *argv++;
               }
               foff = 0;
               read_len = ERR;
               if (asdata)
                       head_len = 0;
               else {
                       head = (EXEC *)hbfr;
                       if ((head_len = read(fileno(stdin),(char *)head,sizeof(EXEC))) == ERR) {
                               perror(file);
                               exit(ERREXIT);
                       }
                       if (head_len == sizeof(EXEC) && !N_BADMAG(*head)) {
                               foff = N_TXTOFF(*head) + head->a_text;
                               if (fseek(stdin,foff,L_SET) == ERR) {
                                       perror(file);
                                       exit(ERREXIT);
                               }
                               read_len = head->a_data;
                               head_len = 0;
                       }
                       else
                               hcnt = 0;
               }
               for (cnt = 0;(ch = getch()) != EOF;) {
                       if (ISSTR(ch)) {
                               if (!cnt)
                                       C = bfr;
                               *C++ = ch;
                               if (++cnt < minlen)
                                       continue;
                               if (oflg)
                                       printf("%07ld %s",foff - minlen,bfr);
                               else
                                       fputs((char *)bfr,stdout);
                               while ((ch = getch()) != EOF && ISSTR(ch))
                                       putchar((char)ch);
                               putchar('\n');
                       }
                       cnt = 0;
               }
       } while (*argv);
       exit(OK);
}

/*
* getch --
*      get next character from wherever
*/
static
getch()
{
       ++foff;
       if (head_len) {
               if (hcnt < head_len)
                       return((int)hbfr[hcnt++]);
               head_len = 0;
       }
       if (read_len == ERR || read_len-- > 0)
               return(getchar());
       return(EOF);
}