xref: /csrg-svn/usr.bin/man/man.c (revision 42402)

/*
 * Copyright (c) 1987 Regents of the University of California.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms are permitted
 * provided that the above copyright notice and this paragraph are
 * duplicated in all such forms and that any documentation,
 * advertising materials, and other materials related to such
 * distribution and use acknowledge that the software was developed
 * by the University of California, Berkeley.  The name of the
 * University may not 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 MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
 */

#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[] = "@(#)man.c	5.20 (Berkeley) 05/27/90";
#endif /* not lint */

#include <sys/param.h>
#include <sys/file.h>
#include <errno.h>
#include <ctype.h>
#include <string.h>
#include <stdlib.h>
#include "pathnames.h"

extern int errno;

int f_all, f_cat, f_where;
char *command, *machine, *p_augment, *p_path, *pager, *progname;

main(argc, argv)
	int argc;
	register char **argv;
{
	extern char *optarg;
	extern int optind;
	int ch, res;
	char *section[2], *check_pager(), *getpath();

	progname = "man";
	while ((ch = getopt(argc, argv, "-acfkM:m:P:w")) != EOF)
		switch((char)ch) {
		case 'a':
			f_all = 1;
			break;
		case 'c':
		case '-':		/* deprecated */
			f_cat = 1;
			break;
		case 'm':
			p_augment = optarg;
			break;
		case 'M':
		case 'P':		/* backward compatibility */
			p_path = optarg;
			break;
		/*
		 * "man -f" and "man -k" are backward compatible, undocumented
		 * ways of calling whatis(1) and apropos(1).
		 */
		case 'f':
			jump(argv, "-f", "whatis");
			/* NOTREACHED */
		case 'k':
			jump(argv, "-k", "apropos");
			/* NOTREACHED */
		case 'w':
			f_all = f_where = 1;
			break;
		case '?':
		default:
			usage();
		}
	argv += optind;

	if (!*argv)
		usage();

	if (!f_cat)
		if (!isatty(1))
			f_cat = 1;
		else if (pager = getenv("PAGER"))
			pager = check_pager(pager);
		else
			pager = _PATH_PAGER;

	if (!(machine = getenv("MACHINE")))
		machine = MACHINE;

	/* see if checking in a specific section */
	if (argc > 1 && getsection(*argv)) {
		section[0] = *argv++;
		section[1] = (char *)NULL;
	} else {
		section[0] = "_default";
		section[1] = (char *)NULL;
	}

	if (!p_path && !(p_path = getenv("MANPATH")) &&
	    !(p_path = getpath(section)) && !p_augment) {
		(void)fprintf(stderr,
		    "man: no place to search for those manual pages.\n");
		exit(1);
	}

	for (; *argv; ++argv) {
		if (p_augment)
			res = manual(p_augment, *argv);
		res = manual(p_path, *argv);
		if (res || f_where)
			continue;
		(void)fprintf(stderr,
		    "man: no entry for %s in the manual.\n", *argv);
		exit(1);
	}

	/* use system(3) in case someone's pager is "pager arg1 arg2" */
	if (command)
		(void)system(command);
	exit(0);
}

/*
 * manual --
 *	given a path, a directory list and a file name, find a file
 *	that matches; check ${directory}/${dir}/{file name} and
 *	${directory}/${dir}/${machine}/${file name}.
 */
manual(path, name)
	char *path, *name;
{
	register int res;
	register char *end;
	char fname[MAXPATHLEN + 1];

	for (res = 0;; path = end + 1) {
		if (!*path)				/* foo: */
			break;
		if (end = index(path, ':')) {
			if (end == path + 1)		/* foo::bar */
				continue;
			*end = '\0';
		}
		(void)sprintf(fname, "%s/%s.0", path, name);
		if (access(fname, R_OK)) {
			(void)sprintf(fname, "%s/%s/%s.0", path, machine, name);
			if (access(fname, R_OK))
				continue;
		}

		if (f_where)
			(void)printf("man: found in %s.\n", fname);
		else if (f_cat)
			cat(fname);
		else
			add(fname);
		if (!f_all)
			return(1);
		res = 1;
		if (!end)
			break;
		*end = ':';
	}
	return(res);
}

/*
 * cat --
 *	cat out the file
 */
cat(fname)
	char *fname;
{
	register int fd, n;
	char buf[BUFSIZ];

	if (!(fd = open(fname, O_RDONLY, 0))) {
		(void)fprintf(stderr, "man: %s: %s\n", fname, strerror(errno));
		exit(1);
	}
	while ((n = read(fd, buf, sizeof(buf))) > 0)
		if (write(1, buf, n) != n) {
			(void)fprintf(stderr,
			    "man: write: %s\n", strerror(errno));
			exit(1);
		}
	if (n == -1) {
		(void)fprintf(stderr, "man: read: %s\n", strerror(errno));
		exit(1);
	}
	(void)close(fd);
}

/*
 * add --
 *	add a file name to the list for future paging
 */
add(fname)
	char *fname;
{
	static u_int buflen;
	static int len;
	static char *cp;
	int flen;

	if (!command) {
		if (!(command = malloc(buflen = 1024)))
			enomem();
		len = strlen(strcpy(command, pager));
		cp = command + len;
	}
	flen = strlen(fname);
	if (len + flen + 2 > buflen) {		/* +2 == space, EOS */
		if (!(command = realloc(command, buflen += 1024)))
			enomem();
		cp = command + len;
	}
	*cp++ = ' ';
	len += flen + 1;			/* +1 = space */
	(void)strcpy(cp, fname);
	cp += flen;
}

/*
 * check_pager --
 *	check the user supplied page information
 */
char *
check_pager(name)
	char *name;
{
	register char *p;
	char *save;

	/*
	 * if the user uses "more", we make it "more -s"; watch out for
	 * PAGER = "mypager /usr/ucb/more"
	 */
	for (p = name; *p && !isspace(*p); ++p);
	for (; p > name && *p != '/'; --p);
	if (p != name)
		++p;

	/* make sure it's "more", not "morex" */
	if (!strncmp(p, "more", 4) && (!p[4] || isspace(p[4]))){
		save = name;
		/* allocate space to add the "-s" */
		if (!(name =
		    malloc((u_int)(strlen(save) + sizeof("-s") + 1))))
			enomem();
		(void)sprintf(name, "%s %s", save, "-s");
	}
	return(name);
}

/*
 * jump --
 *	strip out flag argument and jump
 */
jump(argv, flag, name)
	char **argv, *name;
	register char *flag;
{
	register char **arg;

	argv[0] = name;
	for (arg = argv + 1; *arg; ++arg)
		if (!strcmp(*arg, flag))
			break;
	for (; *arg; ++arg)
		arg[0] = arg[1];
	execvp(name, argv);
	(void)fprintf(stderr, "%s: Command not found.\n", name);
	exit(1);
}

/*
 * usage --
 *	print usage message and die
 */
usage()
{
	(void)fprintf(stderr,
	    "usage: man [-ac] [-M path] [-m path] [section] title ...\n");
	exit(1);
}