date and time created 87/06/29 20:53:49 by bostic

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

/*
* Copyright (c) 1987 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) 1987 Regents of the University of California.\n\
All rights reserved.\n";
#endif not lint

#ifndef lint
static char sccsid[] = "@(#)apropos.c   5.1 (Berkeley) %G%";
#endif not lint

#include <sys/param.h>
#include <stdio.h>
#include <ctype.h>

#define DEF_PATH        "/usr/man"              /* default man path */
#define MAXLINELEN      500                     /* max line handled */
#define NO              0                       /* no/false */
#define WHATIS          "whatis"                /* database name */
#define YES             1                       /* yes/true */

static char     *myname;

main(argc, argv)
       int     argc;
       char    **argv;
{
       extern char     *optarg;
       extern int      optind;
       register char   *beg, *end, **C;
       int     ch, foundman = NO, *found, isapropos,
               a_match(), w_match(), (*match)();
       char    *manpath = NULL,
               buf[MAXLINELEN + 1], fname[MAXPATHLEN + 1],
               wbuf[MAXLINELEN + 1],
               *getenv(), *index(), *malloc(), *rindex();

       myname = (beg = rindex(*argv, '/')) ? beg + 1 : *argv;
       if (!strcmp(myname, "apropos")) {
               isapropos = YES;
               match = a_match;
       }
       else {
               isapropos = NO;
               match = w_match;
       }
       while ((ch = getopt(argc, argv, "M:P:")) != EOF)
               switch((char)ch) {
                       case 'M':
                       case 'P':               /* backward contemptible */
                               manpath = optarg;
                               break;
                       case '?':
                       default:
                               usage();
               }
       argv += optind;
       argc -= optind;
       if (argc < 1)
               usage();

       if (!(manpath = getenv("MANPATH")))
               manpath = DEF_PATH;

       /*NOSTRICT*/
       if (!(found = (int *)malloc((u_int)argc))) {
               fprintf(stderr, "%s: out of space.\n", myname);
               exit(1);
       }
       bzero(found, argc * sizeof(int));       /* calloc is silly */

       if (!isapropos)
               for (C = argv; *C; ++C) {       /* trim full paths */
                       if (beg = rindex(*C, '/'))
                               *C = beg + 1;
               }
       for (C = argv; *C; ++C)                 /* convert to lower-case */
               lowstr(*C, *C);

       for (beg = manpath; beg; beg = end) {   /* through path list */
               end = index(beg, ':');
               if (!end)
                       (void)sprintf(fname, "%s/%s", beg, WHATIS);
               else {
                       (void)sprintf(fname, "%.*s/%s", end - beg, beg, WHATIS);
                       ++end;
               }
                                               /* for each file found */
               if (freopen(fname, "r", stdin)) {
                       foundman = YES;
                       while (gets(buf)) {     /* read & convert to lcase */
                               lowstr(buf, wbuf);
                               for (C = argv; *C; ++C)
                                       if ((*match)(wbuf, *C)) {
                                               puts(buf);
                                               found[C - argv] = YES;

                                               /* only print line once */
                                               while (*++C)
                                                       if ((*match)(wbuf, *C))
                                                               found[C - argv] = YES;
                                               break;
                                       }
                       }
               }
       }
       if (!foundman) {
               fprintf(stderr, "%s: no %s file found in %s.\n", myname, WHATIS, manpath);
               exit(1);
       }
       for (C = argv; *C; C++)
               if (!found[C - argv])
                       printf("%s: %s\n", *C, isapropos ? "nothing appropriate" : "not found");
}

static
a_match(bp, str)
       register char   *bp, *str;
{
       register char   test, *Cs, *Cb;

       if (!*bp)
               return(NO);
       /* backward contemptible: everything matches empty string */
       if (!*str)
               return(YES);
       for (test = *str++; *bp;)
               if (test == *bp++) {
                       Cs = str;
                       Cb = bp;
                       do {
                               if (!*Cs)
                                       return(YES);
                       } while (*Cb++ == *Cs++);
               }
       return(NO);
}

static
w_match(bp, str)
       register char   *bp, *str;
{
       register char   test, *Cs, *Cb;

       if (!*str || !*bp)
               return(NO);
       for (test = *str++; *bp;)
               if (test == *bp++) {
                       for (Cs = str, Cb = bp; *Cs == *Cb; ++Cs, ++Cb);
                       if (!*Cs && (isspace(*Cb) || *Cb == '(' || *Cb == ','))
                               return(YES);
               }
       return(NO);
}

static
lowstr(from, to)
       register char   *from, *to;
{
       for (; *from; ++from, ++to)
               *to = isupper(*from) ? tolower(*from) : *from;
       *to = '\0';
}

static
usage()
{
       fprintf(stderr, "usage: %s [-M path] string ...\n", myname);
       exit(1);
}