dir.c

早期freebsd实现

	/*
	 * See if the result has any wildcards in it. If we find one, call
	 * Dir_Expand right away, telling it to place the result on our list
	 * of expansions.
	 */
	for (cp2 = file; *cp2 != '\0'; cp2++) {
	    switch(*cp2) {
	    case '*':
	    case '?':
	    case '{':
	    case '[':
		Dir_Expand(file, path, expansions);
		goto next;
	    }
	}
	if (*cp2 == '\0') {
	    /*
	     * Hit the end w/o finding any wildcards, so stick the expansion
	     * on the end of the list.
	     */
	    (void)Lst_AtEnd(expansions, file);
	} else {
	next:
	    free(file);
	}
	start = cp+1;
    }
}


/*-
 *-----------------------------------------------------------------------
 * DirExpandInt --
 *	Internal expand routine. Passes through the directories in the
 *	path one by one, calling DirMatchFiles for each. NOTE: This still
 *	doesn't handle patterns in directories...
 *
 * Results:
 *	None.
 *
 * Side Effects:
 *	Things are added to the expansions list.
 *
 *-----------------------------------------------------------------------
 */
static void
DirExpandInt(word, path, expansions)
    char    	  *word;    	/* Word to expand */
    Lst	    	  path;	    	/* Path on which to look */
    Lst	    	  expansions;	/* Place to store the result */
{
    LstNode 	  ln;	    	/* Current node */
    Path	  *p;	    	/* Directory in the node */

    if (Lst_Open(path) == SUCCESS) {
	while ((ln = Lst_Next(path)) != NILLNODE) {
	    p = (Path *)Lst_Datum(ln);
	    DirMatchFiles(word, p, expansions);
	}
	Lst_Close(path);
    }
}

/*-
 *-----------------------------------------------------------------------
 * DirPrintWord --
 *	Print a word in the list of expansions. Callback for Dir_Expand
 *	when DEBUG(DIR), via Lst_ForEach.
 *
 * Results:
 *	=== 0
 *
 * Side Effects:
 *	The passed word is printed, followed by a space.
 *
 *-----------------------------------------------------------------------
 */
static int
DirPrintWord(word)
    char    *word;
{
    printf("%s ", word);

    return(0);
}

/*-
 *-----------------------------------------------------------------------
 * Dir_Expand  --
 *	Expand the given word into a list of words by globbing it looking
 *	in the directories on the given search path.
 *
 * Results:
 *	A list of words consisting of the files which exist along the search
 *	path matching the given pattern.
 *
 * Side Effects:
 *	Directories may be opened. Who knows?
 *-----------------------------------------------------------------------
 */
void
Dir_Expand (word, path, expansions)
    char    *word;      /* the word to expand */
    Lst     path;   	/* the list of directories in which to find
			 * the resulting files */
    Lst	    expansions;	/* the list on which to place the results */
{
    char    	  *cp;

    if (DEBUG(DIR)) {
	printf("expanding \"%s\"...", word);
    }
    
    cp = strchr(word, '{');
    if (cp) {
	DirExpandCurly(word, cp, path, expansions);
    } else {
	cp = strchr(word, '/');
	if (cp) {
	    /*
	     * The thing has a directory component -- find the first wildcard
	     * in the string.
	     */
	    for (cp = word; *cp; cp++) {
		if (*cp == '?' || *cp == '[' || *cp == '*' || *cp == '{') {
		    break;
		}
	    }
	    if (*cp == '{') {
		/*
		 * This one will be fun.
		 */
		DirExpandCurly(word, cp, path, expansions);
		return;
	    } else if (*cp != '\0') {
		/*
		 * Back up to the start of the component
		 */
		char  *dirpath;

		while (cp > word && *cp != '/') {
		    cp--;
		}
		if (cp != word) {
		    char sc;
		    /*
		     * If the glob isn't in the first component, try and find
		     * all the components up to the one with a wildcard.
		     */
		    sc = cp[1];
		    cp[1] = '\0';
		    dirpath = Dir_FindFile(word, path);
		    cp[1] = sc;
		    /*
		     * dirpath is null if can't find the leading component
		     * XXX: Dir_FindFile won't find internal components.
		     * i.e. if the path contains ../Etc/Object and we're
		     * looking for Etc, it won't be found. Ah well.
		     * Probably not important.
		     */
		    if (dirpath != (char *)NULL) {
			char *dp = &dirpath[strlen(dirpath) - 1];
			if (*dp == '/')
			    *dp = '\0';
			path = Lst_Init(FALSE);
			Dir_AddDir(path, dirpath);
			DirExpandInt(cp+1, path, expansions);
			Lst_Destroy(path, NOFREE);
		    }
		} else {
		    /*
		     * Start the search from the local directory
		     */
		    DirExpandInt(word, path, expansions);
		}
	    } else {
		/*
		 * Return the file -- this should never happen.
		 */
		DirExpandInt(word, path, expansions);
	    }
	} else {
	    /*
	     * First the files in dot
	     */
	    DirMatchFiles(word, dot, expansions);
    
	    /*
	     * Then the files in every other directory on the path.
	     */
	    DirExpandInt(word, path, expansions);
	}
    }
    if (DEBUG(DIR)) {
	Lst_ForEach(expansions, DirPrintWord, NULL);
	fputc('\n', stdout);
    }
}

/*-
 *-----------------------------------------------------------------------
 * Dir_FindFile  --
 *	Find the file with the given name along the given search path.
 *
 * Results:
 *	The path to the file or NULL. This path is guaranteed to be in a
 *	different part of memory than name and so may be safely free'd.
 *
 * Side Effects:
 *	If the file is found in a directory which is not on the path
 *	already (either 'name' is absolute or it is a relative path
 *	[ dir1/.../dirn/file ] which exists below one of the directories
 *	already on the search path), its directory is added to the end
 *	of the path on the assumption that there will be more files in
 *	that directory later on. Sometimes this is true. Sometimes not.
 *-----------------------------------------------------------------------
 */
char *
Dir_FindFile (name, path)
    char    	  *name;    /* the file to find */
    Lst           path;	    /* the Lst of directories to search */
{
    register char *p1;	    /* pointer into p->name */
    register char *p2;	    /* pointer into name */
    LstNode       ln;	    /* a list element */
    register char *file;    /* the current filename to check */
    register Path *p;	    /* current path member */
    register char *cp;	    /* index of first slash, if any */
    Boolean	  hasSlash; /* true if 'name' contains a / */
    struct stat	  stb;	    /* Buffer for stat, if necessary */
    Hash_Entry	  *entry;   /* Entry for mtimes table */
    
    /*
     * Find the final component of the name and note whether it has a
     * slash in it (the name, I mean)
     */
    cp = strrchr (name, '/');
    if (cp) {
	hasSlash = TRUE;
	cp += 1;
    } else {
	hasSlash = FALSE;
	cp = name;
    }
    
    if (DEBUG(DIR)) {
	printf("Searching for %s...", name);
    }
    /*
     * No matter what, we always look for the file in the current directory
     * before anywhere else and we *do not* add the ./ to it if it exists.
     * This is so there are no conflicts between what the user specifies
     * (fish.c) and what pmake finds (./fish.c).
     */
    if ((!hasSlash || (cp - name == 2 && *name == '.')) &&
	(Hash_FindEntry (&dot->files, cp) != (Hash_Entry *)NULL)) {
	    if (DEBUG(DIR)) {
		printf("in '.'\n");
	    }
	    hits += 1;
	    dot->hits += 1;
	    return (strdup (name));
    }
    
    if (Lst_Open (path) == FAILURE) {
	if (DEBUG(DIR)) {
	    printf("couldn't open path, file not found\n");
	}
	misses += 1;
	return ((char *) NULL);
    }
    
    /*
     * We look through all the directories on the path seeking one which
     * contains the final component of the given name and whose final
     * component(s) match the name's initial component(s). If such a beast
     * is found, we concatenate the directory name and the final component
     * and return the resulting string. If we don't find any such thing,
     * we go on to phase two...
     */
    while ((ln = Lst_Next (path)) != NILLNODE) {
	p = (Path *) Lst_Datum (ln);
	if (DEBUG(DIR)) {
	    printf("%s...", p->name);
	}
	if (Hash_FindEntry (&p->files, cp) != (Hash_Entry *)NULL) {
	    if (DEBUG(DIR)) {
		printf("here...");
	    }
	    if (hasSlash) {
		/*
		 * If the name had a slash, its initial components and p's
		 * final components must match. This is false if a mismatch
		 * is encountered before all of the initial components
		 * have been checked (p2 > name at the end of the loop), or
		 * we matched only part of one of the components of p
		 * along with all the rest of them (*p1 != '/').
		 */
		p1 = p->name + strlen (p->name) - 1;
		p2 = cp - 2;
		while (p2 >= name && *p1 == *p2) {
		    p1 -= 1; p2 -= 1;
		}
		if (p2 >= name || (p1 >= p->name && *p1 != '/')) {
		    if (DEBUG(DIR)) {
			printf("component mismatch -- continuing...");
		    }
		    continue;
		}
	    }
	    file = str_concat (p->name, cp, STR_ADDSLASH);
	    if (DEBUG(DIR)) {
		printf("returning %s\n", file);
	    }
	    Lst_Close (path);
	    p->hits += 1;
	    hits += 1;
	    return (file);
	} else if (hasSlash) {
	    /*
	     * If the file has a leading path component and that component
	     * exactly matches the entire name of the current search
	     * directory, we assume the file doesn't exist and return NULL.
	     */
	    for (p1 = p->name, p2 = name; *p1 && *p1 == *p2; p1++, p2++) {
		continue;
	    }
	    if (*p1 == '\0' && p2 == cp - 1) {
		if (DEBUG(DIR)) {
		    printf("must be here but isn't -- returing NULL\n");
		}
		Lst_Close (path);
		return ((char *) NULL);
	    }
	}
    }
    
    /*
     * We didn't find the file on any existing members of the directory.
     * If the name doesn't contain a slash, that means it doesn't exist.
     * If it *does* contain a slash, however, there is still hope: it
     * could be in a subdirectory of one of the members of the search
     * path. (eg. /usr/include and sys/types.h. The above search would
     * fail to turn up types.h in /usr/include, but it *is* in
     * /usr/include/sys/types.h) If we find such a beast, we assume there
     * will be more (what else can we assume?) and add all but the last
     * component of the resulting name onto the search path (at the
     * end). This phase is only performed if the file is *not* absolute.
     */
    if (!hasSlash) {
	if (DEBUG(DIR)) {
	    printf("failed.\n");
	}
	misses += 1;
	return ((char *) NULL);
    }
    
    if (*name != '/') {
	Boolean	checkedDot = FALSE;
	
	if (DEBUG(DIR)) {
	    printf("failed. Trying subdirectories...");
	}
	(void) Lst_Open (path);
	while ((ln = Lst_Next (path)) != NILLNODE) {
	    p = (Path *) Lst_Datum (ln);
	    if (p != dot) {
		file = str_concat (p->name, name, STR_ADDSLASH);
	    } else {
		/*
		 * Checking in dot -- DON'T put a leading ./ on the thing.
		 */
		file = strdup(name);
		checkedDot = TRUE;
	    }
	    if (DEBUG(DIR)) {
		printf("checking %s...", file);
	    }
	    
		
	    if (stat (file, &stb) == 0) {
		if (DEBUG(DIR)) {
		    printf("got it.\n");
		}
		
		Lst_Close (path);
		
		/*
		 * We've found another directory to search. We know there's
		 * a slash in 'file' because we put one there. We nuke it after
		 * finding it and call Dir_AddDir to add this new directory
		 * onto the existing search path. Once that's done, we restore
		 * the slash and triumphantly return the file name, knowing
		 * that should a file in this directory every be referenced
		 * again in such a manner, we will find it without having to do
		 * numerous numbers of access calls. Hurrah!
		 */
		cp = strrchr (file, '/');
		*cp = '\0';
		Dir_AddDir (path, file);
		*cp = '/';
		
		/*
		 * Save the modification time so if it's needed, we don't have
		 * to fetch it again.
		 */
		if (DEBUG(DIR)) {
		    printf("Caching %s for %s\n", Targ_FmtTime(stb.st_mtime),
			    file);
		}
		entry = Hash_CreateEntry(&mtimes, (char *) file,
					 (Boolean *)NULL);