BSD 4_3_Reno release

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

/*
* Copyright (c) 1980, 1987 The Regents of the University of California.
* All rights reserved.
*
* Redistribution and use in source and binary forms are permitted
* provided that: (1) source distributions retain this entire copyright
* notice and comment, and (2) distributions including binaries display
* the following acknowledgement:  ``This product includes software
* developed by the University of California, Berkeley and its contributors''
* in the documentation or other materials provided with the distribution
* and in all advertising materials mentioning features or use of this
* software. Neither the name of the University nor the names of its
* contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
*/

#ifndef lint
char copyright[] =
"@(#) Copyright (c) 1980, 1987 The Regents of the University of California.\n\
All rights reserved.\n";
#endif /* not lint */

#ifndef lint
static char sccsid[] = "@(#)strings.c   5.6 (Berkeley) 6/1/90";
#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 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;
{
       extern char *optarg;
       extern int optind;
       register int ch, cnt;
       register u_char *C;
       EXEC *head;
       int minlen;
       short asdata, oflg;
       u_char *bfr;
       char *file, *p, *malloc();

       /*
        * for backward compatibility, allow '-' to specify 'a' flag; no
        * longer documented in the man page or usage string.
        */
       asdata = oflg = 0;
       minlen = -1;
       while ((ch = getopt(argc, argv, "-0123456789ao")) != EOF)
               switch((char)ch) {
               case '0': case '1': case '2': case '3': case '4':
               case '5': case '6': case '7': case '8': case '9':
                       /*
                        * kludge: strings was originally designed to take
                        * a number after a dash.
                        */
                       if (minlen == -1) {
                               p = argv[optind - 1];
                               if (p[0] == '-' && p[1] == ch && !p[2])
                                       minlen = atoi(++p);
                               else
                                       minlen = atoi(argv[optind] + 1);
                       }
                       break;
               case '-':
               case 'a':
                       asdata = 1;
                       break;
               case 'o':
                       oflg = 1;
                       break;
               case '?':
               default:
                       fprintf(stderr,
                           "usage: strings [-ao] [-#] [file ... ]\n");
                       exit(1);
               }
       argc -= optind;
       argv += optind;

       if (minlen == -1)
               minlen = DEF_LEN;

       if (!(bfr = (u_char *)malloc((u_int)minlen))) {
               fputs("strings: no space.\n", stderr);
               exit(1);
       }
       bfr[minlen] = '\0';
       file = "stdin";
       do {
               if (*argv) {
                       if (!freopen(*argv, "r", stdin)) {
                               perror(*argv);
                               exit(1);
                       }
                       file = *argv++;
               }
               foff = 0;
               read_len = -1;
               if (asdata)
                       head_len = 0;
               else {
                       head = (EXEC *)hbfr;
                       if ((head_len = read(fileno(stdin), (char *)head, sizeof(EXEC))) == -1) {
                               perror(file);
                               exit(1);
                       }
                       if (head_len == sizeof(EXEC) && !N_BADMAG(*head)) {
                               foff = N_TXTOFF(*head) + head->a_text;
                               if (fseek(stdin, foff, L_SET) == -1) {
                                       perror(file);
                                       exit(1);
                               }
                               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,
                                           (char *)bfr);
                               else
                                       fputs((char *)bfr, stdout);
                               while ((ch = getch()) != EOF && ISSTR(ch))
                                       putchar((char)ch);
                               putchar('\n');
                       }
                       cnt = 0;
               }
       } while (*argv);
       exit(0);
}

/*
* getch --
*      get next character from wherever
*/
getch()
{
       ++foff;
       if (head_len) {
               if (hcnt < head_len)
                       return((int)hbfr[hcnt++]);
               head_len = 0;
       }
       if (read_len == -1 || read_len-- > 0)
               return(getchar());
       return(EOF);
}