BSD 4_3_Net_2 release

[unix-history] / usr / src / usr.bin / 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, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
*    notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
*    notice, this list of conditions and the following disclaimer in the
*    documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
*    must display the following acknowledgement:
*      This product includes software developed by the University of
*      California, Berkeley and its contributors.
* 4. 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 BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/

#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   5.10 (Berkeley) 5/23/91";
#endif /* not lint */

#include <sys/types.h>
#include <fcntl.h>
#include <errno.h>
#include <a.out.h>
#include <unistd.h>
#include <stdio.h>
#include <ctype.h>
#include <stdlib.h>
#include <string.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 */

static void usage();

main(argc, argv)
       int argc;
       char **argv;
{
       extern char *optarg;
       extern int optind;
       register int ch, cnt;
       register u_char *C;
       EXEC *head;
       int exitcode, minlen;
       short asdata, oflg, fflg;
       u_char *bfr;
       char *file, *p;

       /*
        * for backward compatibility, allow '-' to specify 'a' flag; no
        * longer documented in the man page or usage string.
        */
       asdata = exitcode = fflg = oflg = 0;
       minlen = -1;
       while ((ch = getopt(argc, argv, "-0123456789anof")) != 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 'f':
                       fflg = 1;
                       break;
               case 'n':
                       minlen = atoi(optarg);
                       break;
               case 'o':
                       oflg = 1;
                       break;
               case '?':
               default:
                       usage();
               }
       argc -= optind;
       argv += optind;

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

       if (!(bfr = malloc((u_int)minlen))) {
               (void)fprintf(stderr, "strings: %s\n", strerror(errno));
               exit(1);
       }
       bfr[minlen] = '\0';
       file = "stdin";
       do {
               if (*argv) {
                       file = *argv++;
                       if (!freopen(file, "r", stdin)) {
                               (void)fprintf(stderr,
                                   "strings; %s: %s\n", file, strerror(errno));
                               exitcode = 1;
                               goto nextfile;
                       }
               }
               foff = 0;
#define DO_EVERYTHING()         {read_len = -1; head_len = 0; goto start;}
               read_len = -1;
               if (asdata)
                       DO_EVERYTHING()
               else {
                       head = (EXEC *)hbfr;
                       if ((head_len =
                           read(fileno(stdin), head, sizeof(EXEC))) == -1)
                               DO_EVERYTHING()
                       if (head_len == sizeof(EXEC) && !N_BADMAG(*head)) {
                               foff = N_TXTOFF(*head);
                               if (fseek(stdin, foff, SEEK_SET) == -1)
                                       DO_EVERYTHING()
                               read_len = head->a_text + head->a_data;
                               head_len = 0;
                       }
                       else
                               hcnt = 0;
               }
start:
               for (cnt = 0; (ch = getch()) != EOF;) {
                       if (ISSTR(ch)) {
                               if (!cnt)
                                       C = bfr;
                               *C++ = ch;
                               if (++cnt < minlen)
                                       continue;
                               if (fflg)
                                       printf("%s:", file);
                               if (oflg)
                                       printf("%07ld %s",
                                           foff - minlen, (char *)bfr);
                               else
                                       printf("%s", bfr);
                               while ((ch = getch()) != EOF && ISSTR(ch))
                                       putchar((char)ch);
                               putchar('\n');
                       }
                       cnt = 0;
               }
nextfile: ;
       } while (*argv);
       exit(exitcode);
}

/*
* 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);
}

static void
usage()
{
       (void)fprintf(stderr,
           "usage: strings [-afo] [-n length] [file ... ]\n");
       exit(1);
}