Import the [now] dual licensed version 3.5.4 of less. It is

distributed under your choice of the GPL or a BSD style license.

Reviewed by:	peter
Obtained from:	http://home.flash.net/~marknu/less/

1 files changed, 1011 insertions, 0 deletions

diff --git a/contrib/less/filename.c b/contrib/less/filename.c
new file mode 100644
index 0000000..189ad87
--- /dev/null
+++ b/contrib/less/filename.c
@@ -0,0 +1,1011 @@
+/*
+ * Copyright (C) 1984-2000  Mark Nudelman
+ *
+ * You may distribute under the terms of either the GNU General Public
+ * License or the Less License, as specified in the README file.
+ *
+ * For more information about less, or for information on how to 
+ * contact the author, see the README file.
+ */
+
+
+/*
+ * Routines to mess around with filenames (and files).
+ * Much of this is very OS dependent.
+ */
+
+#include "less.h"
+#include "lglob.h"
+#if MSDOS_COMPILER
+#include <dos.h>
+#if MSDOS_COMPILER==WIN32C && !defined(_MSC_VER)
+#include <dir.h>
+#endif
+#if MSDOS_COMPILER==DJGPPC
+#include <glob.h>
+#include <dir.h>
+#include <limits.h>
+#define _MAX_PATH	PATH_MAX
+#endif
+#endif
+#ifdef _OSK
+#include <rbf.h>
+#ifndef _OSK_MWC32
+#include <modes.h>
+#endif
+#endif
+
+#if HAVE_STAT
+#include <sys/stat.h>
+#ifndef S_ISDIR
+#define	S_ISDIR(m)	(((m) & S_IFMT) == S_IFDIR)
+#endif
+#ifndef S_ISREG
+#define	S_ISREG(m)	(((m) & S_IFMT) == S_IFREG)
+#endif
+#endif
+
+
+extern int force_open;
+extern int secure;
+extern IFILE curr_ifile;
+extern IFILE old_ifile;
+#if SPACES_IN_FILENAMES
+extern char openquote;
+extern char closequote;
+#endif
+
+/*
+ * Remove quotes around a filename.
+ */
+	public char *
+unquote_file(str)
+	char *str;
+{
+#if SPACES_IN_FILENAMES
+	char *name;
+	char *p;
+
+	if (*str != openquote)
+		return (save(str));
+	name = (char *) ecalloc(strlen(str), sizeof(char));
+	strcpy(name, str+1);
+	p = name + strlen(name) - 1;
+	if (*p == closequote)
+		*p = '\0';
+	return (name);
+#else
+	return (save(str));
+#endif
+}
+
+/*
+ * Return a pathname that points to a specified file in a specified directory.
+ * Return NULL if the file does not exist in the directory.
+ */
+	static char *
+dirfile(dirname, filename)
+	char *dirname;
+	char *filename;
+{
+	char *pathname;
+	char *qpathname;
+	int f;
+
+	if (dirname == NULL || *dirname == '\0')
+		return (NULL);
+	/*
+	 * Construct the full pathname.
+	 */
+	pathname = (char *) calloc(strlen(dirname) + strlen(filename) + 2, 
+					sizeof(char));
+	if (pathname == NULL)
+		return (NULL);
+	sprintf(pathname, "%s%s%s", dirname, PATHNAME_SEP, filename);
+	/*
+	 * Make sure the file exists.
+	 */
+	qpathname = unquote_file(pathname);
+	f = open(qpathname, OPEN_READ);
+	if (f < 0)
+	{
+		free(pathname);
+		pathname = NULL;
+	} else
+	{
+		close(f);
+	}
+	free(qpathname);
+	return (pathname);
+}
+
+/*
+ * Return the full pathname of the given file in the "home directory".
+ */
+	public char *
+homefile(filename)
+	char *filename;
+{
+	register char *pathname;
+
+	/*
+	 * Try $HOME/filename.
+	 */
+	pathname = dirfile(lgetenv("HOME"), filename);
+	if (pathname != NULL)
+		return (pathname);
+#if OS2
+	/*
+	 * Try $INIT/filename.
+	 */
+	pathname = dirfile(lgetenv("INIT"), filename);
+	if (pathname != NULL)
+		return (pathname);
+#endif
+#if MSDOS_COMPILER || OS2
+	/*
+	 * Look for the file anywhere on search path.
+	 */
+	pathname = (char *) calloc(_MAX_PATH, sizeof(char));
+#if MSDOS_COMPILER==DJGPPC
+	{
+		char *res = searchpath(filename);
+		if (res == 0)
+			*pathname = '\0';
+		else
+			strcpy(pathname, res);
+	}
+#else
+	_searchenv(filename, "PATH", pathname);
+#endif
+	if (*pathname != '\0')
+		return (pathname);
+	free(pathname);
+#endif
+	return (NULL);
+}
+
+/*
+ * Expand a string, substituting any "%" with the current filename,
+ * and any "#" with the previous filename.
+ * But a string of N "%"s is just replaced with N-1 "%"s.
+ * Likewise for a string of N "#"s.
+ * {{ This is a lot of work just to support % and #. }}
+ */
+	public char *
+fexpand(s)
+	char *s;
+{
+	register char *fr, *to;
+	register int n;
+	register char *e;
+	IFILE ifile;
+
+#define	fchar_ifile(c) \
+	((c) == '%' ? curr_ifile : \
+	 (c) == '#' ? old_ifile : NULL_IFILE)
+
+	/*
+	 * Make one pass to see how big a buffer we 
+	 * need to allocate for the expanded string.
+	 */
+	n = 0;
+	for (fr = s;  *fr != '\0';  fr++)
+	{
+		switch (*fr)
+		{
+		case '%':
+		case '#':
+			if (fr > s && fr[-1] == *fr)
+			{
+				/*
+				 * Second (or later) char in a string
+				 * of identical chars.  Treat as normal.
+				 */
+				n++;
+			} else if (fr[1] != *fr)
+			{
+				/*
+				 * Single char (not repeated).  Treat specially.
+				 */
+				ifile = fchar_ifile(*fr);
+				if (ifile == NULL_IFILE)
+					n++;
+				else
+					n += strlen(get_filename(ifile));
+			}
+			/*
+			 * Else it is the first char in a string of
+			 * identical chars.  Just discard it.
+			 */
+			break;
+		default:
+			n++;
+			break;
+		}
+	}
+
+	e = (char *) ecalloc(n+1, sizeof(char));
+
+	/*
+	 * Now copy the string, expanding any "%" or "#".
+	 */
+	to = e;
+	for (fr = s;  *fr != '\0';  fr++)
+	{
+		switch (*fr)
+		{
+		case '%':
+		case '#':
+			if (fr > s && fr[-1] == *fr)
+			{
+				*to++ = *fr;
+			} else if (fr[1] != *fr)
+			{
+				ifile = fchar_ifile(*fr);
+				if (ifile == NULL_IFILE)
+					*to++ = *fr;
+				else
+				{
+					strcpy(to, get_filename(ifile));
+					to += strlen(to);
+				}
+			}
+			break;
+		default:
+			*to++ = *fr;
+			break;
+		}
+	}
+	*to = '\0';
+	return (e);
+}
+
+#if TAB_COMPLETE_FILENAME
+
+/*
+ * Return a blank-separated list of filenames which "complete"
+ * the given string.
+ */
+	public char *
+fcomplete(s)
+	char *s;
+{
+	char *fpat;
+
+	if (secure)
+		return (NULL);
+	/*
+	 * Complete the filename "s" by globbing "s*".
+	 */
+#if MSDOS_COMPILER && (MSDOS_COMPILER == MSOFTC || MSDOS_COMPILER == BORLANDC)
+	/*
+	 * But in DOS, we have to glob "s*.*".
+	 * But if the final component of the filename already has
+	 * a dot in it, just do "s*".  
+	 * (Thus, "FILE" is globbed as "FILE*.*", 
+	 *  but "FILE.A" is globbed as "FILE.A*").
+	 */
+	{
+		char *slash;
+		for (slash = s+strlen(s)-1;  slash > s;  slash--)
+			if (*slash == *PATHNAME_SEP || *slash == '/')
+				break;
+		fpat = (char *) ecalloc(strlen(s)+4, sizeof(char));
+		if (strchr(slash, '.') == NULL)
+			sprintf(fpat, "%s*.*", s);
+		else
+			sprintf(fpat, "%s*", s);
+	}
+#else
+	fpat = (char *) ecalloc(strlen(s)+2, sizeof(char));
+	sprintf(fpat, "%s*", s);
+#endif
+	s = lglob(fpat);
+	if (strcmp(s,fpat) == 0)
+	{
+		/*
+		 * The filename didn't expand.
+		 */
+		free(s);
+		s = NULL;
+	}
+	free(fpat);
+	return (s);
+}
+#endif
+
+/*
+ * Try to determine if a file is "binary".
+ * This is just a guess, and we need not try too hard to make it accurate.
+ */
+	public int
+bin_file(f)
+	int f;
+{
+	int i;
+	int n;
+	unsigned char data[64];
+
+	if (!seekable(f))
+		return (0);
+	if (lseek(f, (off_t)0, 0) == BAD_LSEEK)
+		return (0);
+	n = read(f, data, sizeof(data));
+	for (i = 0;  i < n;  i++)
+		if (binary_char(data[i]))
+			return (1);
+	return (0);
+}
+
+/*
+ * Try to determine the size of a file by seeking to the end.
+ */
+	static POSITION
+seek_filesize(f)
+	int f;
+{
+	off_t spos;
+
+	spos = lseek(f, (off_t)0, 2);
+	if (spos == BAD_LSEEK)
+		return (NULL_POSITION);
+	return ((POSITION) spos);
+}
+
+/*
+ * Read a string from a file.
+ * Return a pointer to the string in memory.
+ */
+	static char *
+readfd(fd)
+	FILE *fd;
+{
+	int len;
+	int ch;
+	char *buf;
+	char *p;
+	
+	/* 
+	 * Make a guess about how many chars in the string
+	 * and allocate a buffer to hold it.
+	 */
+	len = 100;
+	buf = (char *) ecalloc(len, sizeof(char));
+	for (p = buf;  ;  p++)
+	{
+		if ((ch = getc(fd)) == '\n' || ch == EOF)
+			break;
+		if (p - buf >= len-1)
+		{
+			/*
+			 * The string is too big to fit in the buffer we have.
+			 * Allocate a new buffer, twice as big.
+			 */
+			len *= 2;
+			*p = '\0';
+			p = (char *) ecalloc(len, sizeof(char));
+			strcpy(p, buf);
+			free(buf);
+			buf = p;
+			p = buf + strlen(buf);
+		}
+		*p = ch;
+	}
+	*p = '\0';
+	return (buf);
+}
+
+#if HAVE_SHELL
+
+/*
+ * Get the shell's escape character.
+ */
+	static char *
+get_meta_escape()
+{
+	char *s;
+
+	s = lgetenv("LESSMETAESCAPE");
+	if (s == NULL)
+		s = DEF_METAESCAPE;
+	return (s);
+}
+
+/*
+ * Is this a shell metacharacter?
+ */
+	static int
+metachar(c)
+	char c;
+{
+	static char *metachars = NULL;
+
+	if (metachars == NULL)
+	{
+		metachars = lgetenv("LESSMETACHARS");
+		if (metachars == NULL)
+			metachars = DEF_METACHARS;
+	}
+	return (strchr(metachars, c) != NULL);
+}
+
+/*
+ * Insert a backslash before each metacharacter in a string.
+ */
+	public char *
+esc_metachars(s)
+	char *s;
+{
+	char *p;
+	char *newstr;
+	int len;
+	char *esc;
+	int esclen;
+
+	/*
+	 * Determine how big a string we need to allocate.
+	 */
+	esc = get_meta_escape();
+	esclen = strlen(esc);
+	len = 1; /* Trailing null byte */
+	for (p = s;  *p != '\0';  p++)
+	{
+		len++;
+		if (metachar(*p))
+		{
+			if (*esc == '\0')
+			{
+				/*
+				 * We've got a metachar, but this shell 
+				 * doesn't support escape chars.  Give up.
+				 */
+				return (NULL);
+			}
+			/*
+			 * Allow space for the escape char.
+			 */
+			len += esclen;
+		}
+	}
+	/*
+	 * Allocate and construct the new string.
+	 */
+	newstr = p = (char *) ecalloc(len, sizeof(char));
+	while (*s != '\0')
+	{
+		if (metachar(*s))
+		{
+			/*
+			 * Add the escape char.
+			 */
+			strcpy(p, esc);
+			p += esclen;
+		}
+		*p++ = *s++;
+	}
+	*p = '\0';
+	return (newstr);
+}
+
+#else /* HAVE_SHELL */
+
+	public char *
+esc_metachars(s)
+	char *s;
+{
+	return (save(s));
+}
+
+#endif /* HAVE_SHELL */
+
+
+#if HAVE_POPEN
+
+FILE *popen();
+
+/*
+ * Execute a shell command.
+ * Return a pointer to a pipe connected to the shell command's standard output.
+ */
+	static FILE *
+shellcmd(cmd)
+	char *cmd;
+{
+	FILE *fd;
+
+#if HAVE_SHELL
+	char *shell;
+
+	shell = lgetenv("SHELL");
+	if (shell != NULL && *shell != '\0')
+	{
+		char *scmd;
+		char *esccmd;
+
+		/*
+		 * Try to escape any metacharacters in the command.
+		 * If we can't do that, just put the command in quotes.
+		 * (But that doesn't work well if the command itself 
+		 * contains quotes.)
+		 */
+		if ((esccmd = esc_metachars(cmd)) == NULL)
+		{
+			/*
+			 * Cannot escape the metacharacters, so use quotes.
+			 * Read the output of <$SHELL -c "cmd">.
+			 */
+			scmd = (char *) ecalloc(strlen(shell) + strlen(cmd) + 7,
+						sizeof(char));
+			sprintf(scmd, "%s -c \"%s\"", shell, cmd);
+		} else
+		{
+			/*
+			 * Read the output of <$SHELL -c cmd>.  
+			 * No quotes; use the escaped cmd.
+			 */
+			scmd = (char *) ecalloc(strlen(shell) + strlen(esccmd) + 5,
+						sizeof(char));
+			sprintf(scmd, "%s -c %s", shell, esccmd);
+			free(esccmd);
+		}
+		fd = popen(scmd, "r");
+		free(scmd);
+	} else
+#endif
+	{
+		fd = popen(cmd, "r");
+		/*
+		 * Redirection in `popen' might have messed with the
+		 * standard devices.  Restore binary input mode.
+		 */
+		SET_BINARY(0);
+	}
+	return (fd);
+}
+
+#endif /* HAVE_POPEN */
+
+
+/*
+ * Expand a filename, doing any system-specific metacharacter substitutions.
+ */
+	public char *
+lglob(filename)
+	char *filename;
+{
+	char *gfilename;
+	char *ofilename;
+
+	ofilename = fexpand(filename);
+	if (secure)
+		return (ofilename);
+	filename = unquote_file(ofilename);
+
+#ifdef DECL_GLOB_LIST
+{
+	/*
+	 * The globbing function returns a list of names.
+	 */
+	int length;
+	char *p;
+	DECL_GLOB_LIST(list)
+
+	GLOB_LIST(filename, list);
+	if (GLOB_LIST_FAILED(list))
+	{
+		free(filename);
+		return (ofilename);
+	}
+	length = 1; /* Room for trailing null byte */
+	for (SCAN_GLOB_LIST(list, p))
+	{
+		INIT_GLOB_LIST(list, p);
+	  	length += strlen(p) + 1;
+#if SPACES_IN_FILENAMES
+		if (strchr(p, ' ') != NULL)
+			length += 2; /* Allow for quotes */
+#endif
+	}
+	gfilename = (char *) ecalloc(length, sizeof(char));
+	for (SCAN_GLOB_LIST(list, p))
+	{
+		INIT_GLOB_LIST(list, p);
+#if SPACES_IN_FILENAMES
+		if (strchr(p, ' ') != NULL)
+			sprintf(gfilename + strlen(gfilename), "%c%s%c ",
+				openquote, p, closequote);
+		else
+#endif
+			sprintf(gfilename + strlen(gfilename), "%s ", p);
+	}
+	/*
+	 * Overwrite the final trailing space with a null terminator.
+	 */
+	*--p = '\0';
+	GLOB_LIST_DONE(list);
+}
+#else
+#ifdef DECL_GLOB_NAME
+{
+	/*
+	 * The globbing function returns a single name, and
+	 * is called multiple times to walk thru all names.
+	 */
+	register char *p;
+	register int len;
+	register int n;
+#if SPACES_IN_FILENAMES
+	register int spaces_in_file;
+#endif
+	DECL_GLOB_NAME(fnd,drive,dir,fname,ext,handle)
+	
+	GLOB_FIRST_NAME(filename, &fnd, handle);
+	if (GLOB_FIRST_FAILED(handle))
+	{
+		free(filename);
+		return (ofilename);
+	}
+
+	_splitpath(filename, drive, dir, fname, ext);
+	len = 100;
+	gfilename = (char *) ecalloc(len, sizeof(char));
+	p = gfilename;
+	do {
+		n = strlen(drive) + strlen(dir) + strlen(fnd.GLOB_NAME) + 1;
+#if SPACES_IN_FILENAMES
+		spaces_in_file = 0;
+		if (strchr(fnd.GLOB_NAME, ' ') != NULL ||
+		    strchr(filename, ' ') != NULL)
+		{
+			spaces_in_file = 1;
+			n += 2;
+		}
+#endif
+		while (p - gfilename + n+2 >= len)
+		{
+			/*
+			 * No room in current buffer.  Allocate a bigger one.
+			 */
+			len *= 2;
+			*p = '\0';
+			p = (char *) ecalloc(len, sizeof(char));
+			strcpy(p, gfilename);
+			free(gfilename);
+			gfilename = p;
+			p = gfilename + strlen(gfilename);
+		}
+#if SPACES_IN_FILENAMES
+		if (spaces_in_file)
+			sprintf(p, "%c%s%s%s%c ", openquote, 
+				drive, dir, fnd.GLOB_NAME, closequote);
+		else
+#endif
+			sprintf(p, "%s%s%s ", drive, dir, fnd.GLOB_NAME);
+		p += n;
+	} while (GLOB_NEXT_NAME(handle, &fnd) == 0);
+
+	/*
+	 * Overwrite the final trailing space with a null terminator.
+	 */
+	*--p = '\0';
+	GLOB_NAME_DONE(handle);
+}
+#else
+#if HAVE_POPEN
+{
+	/*
+	 * We get the shell to glob the filename for us by passing
+	 * an "echo" command to the shell and reading its output.
+	 */
+	FILE *fd;
+	char *s;
+	char *lessecho;
+	char *cmd;
+
+	lessecho = lgetenv("LESSECHO");
+	if (lessecho == NULL || *lessecho == '\0')
+		lessecho = "lessecho";
+	s = esc_metachars(filename);
+	if (s == NULL)
+	{
+		/*
+		 * There may be dangerous metachars in this name.
+		 * We can't risk passing it to the shell.
+		 * {{ For example, do "!;TAB" when the first file 
+		 *    in the dir is named "rm". }}
+		 */
+		free(filename);
+		return (ofilename);
+	}
+	/*
+	 * Invoke lessecho, and read its output (a globbed list of filenames).
+	 */
+	cmd = (char *) ecalloc(strlen(lessecho) + strlen(s) + 24, sizeof(char));
+	sprintf(cmd, "%s -p0x%x -d0x%x -- %s", 
+		lessecho, openquote, closequote, s);
+	fd = shellcmd(cmd);
+	free(s);
+	free(cmd);
+	if (fd == NULL)
+	{
+		/*
+		 * Cannot create the pipe.
+		 * Just return the original (fexpanded) filename.
+		 */
+		free(filename);
+		return (ofilename);
+	}
+	gfilename = readfd(fd);
+	pclose(fd);
+	if (*gfilename == '\0')
+	{
+		free(gfilename);
+		free(filename);
+		return (ofilename);
+	}
+}
+#else
+	/*
+	 * No globbing functions at all.  Just use the fexpanded filename.
+	 */
+	gfilename = save(filename);
+#endif
+#endif
+#endif
+	free(filename);
+	free(ofilename);
+	return (gfilename);
+}
+
+/*
+ * See if we should open a "replacement file" 
+ * instead of the file we're about to open.
+ */
+	public char *
+open_altfile(filename, pf, pfd)
+	char *filename;
+	int *pf;
+	void **pfd;
+{
+#if !HAVE_POPEN
+	return (NULL);
+#else
+	char *lessopen;
+	char *gfilename;
+	char *cmd;
+	FILE *fd;
+#if HAVE_FILENO
+	int returnfd = 0;
+#endif
+	
+	if (secure)
+		return (NULL);
+	ch_ungetchar(-1);
+	if ((lessopen = lgetenv("LESSOPEN")) == NULL)
+		return (NULL);
+	if (strcmp(filename, "-") == 0)
+		return (NULL);
+	if (*lessopen == '|')
+	{
+		/*
+		 * If LESSOPEN starts with a |, it indicates 
+		 * a "pipe preprocessor".
+		 */
+#if HAVE_FILENO
+		lessopen++;
+		returnfd = 1;
+#else
+		error("LESSOPEN pipe is not supported", NULL_PARG);
+		return (NULL);
+#endif
+	}
+
+	gfilename = esc_metachars(filename);
+	if (gfilename == NULL)
+	{
+		/*
+		 * Cannot escape metacharacters.
+		 */
+		return (NULL);
+	}
+	cmd = (char *) ecalloc(strlen(lessopen) + strlen(gfilename) + 2, 
+			sizeof(char));
+	sprintf(cmd, lessopen, gfilename);
+	fd = shellcmd(cmd);
+	free(gfilename);
+	free(cmd);
+	if (fd == NULL)
+	{
+		/*
+		 * Cannot create the pipe.
+		 */
+		return (NULL);
+	}
+#if HAVE_FILENO
+	if (returnfd)
+	{
+		int f;
+		char c;
+
+		/*
+		 * Read one char to see if the pipe will produce any data.
+		 * If it does, push the char back on the pipe.
+		 */
+		f = fileno(fd);
+		SET_BINARY(f);
+		if (read(f, &c, 1) != 1)
+		{
+			/*
+			 * Pipe is empty.  This means there is no alt file.
+			 */
+			pclose(fd);
+			return (NULL);
+		}
+		ch_ungetchar(c);
+		*pfd = (void *) fd;
+		*pf = f;
+		return (save("-"));
+	}
+#endif
+	gfilename = readfd(fd);
+	pclose(fd);
+	if (*gfilename == '\0')
+		/*
+		 * Pipe is empty.  This means there is no alt file.
+		 */
+		return (NULL);
+	return (gfilename);
+#endif /* HAVE_POPEN */
+}
+
+/*
+ * Close a replacement file.
+ */
+	public void
+close_altfile(altfilename, filename, pipefd)
+	char *altfilename;
+	char *filename;
+	void *pipefd;
+{
+#if HAVE_POPEN
+	char *lessclose;
+	char *gfilename;
+	char *galtfilename;
+	FILE *fd;
+	char *cmd;
+	
+	if (secure)
+		return;
+	if (pipefd != NULL)
+		pclose((FILE*) pipefd);
+	if ((lessclose = lgetenv("LESSCLOSE")) == NULL)
+	     	return;
+	gfilename = esc_metachars(filename);
+	if (gfilename == NULL)
+	{
+		return;
+	}
+	galtfilename = esc_metachars(altfilename);
+	if (galtfilename == NULL)
+	{
+		free(gfilename);
+		return;
+	}
+	cmd = (char *) ecalloc(strlen(lessclose) + strlen(gfilename) + 
+			strlen(galtfilename) + 2, sizeof(char));
+	sprintf(cmd, lessclose, gfilename, galtfilename);
+	fd = shellcmd(cmd);
+	free(galtfilename);
+	free(gfilename);
+	free(cmd);
+	if (fd != NULL)
+		pclose(fd);
+#endif
+}
+		
+/*
+ * Is the specified file a directory?
+ */
+	public int
+is_dir(filename)
+	char *filename;
+{
+	int isdir = 0;
+
+	filename = unquote_file(filename);
+#if HAVE_STAT
+{
+	int r;
+	struct stat statbuf;
+
+	r = stat(filename, &statbuf);
+	isdir = (r >= 0 && S_ISDIR(statbuf.st_mode));
+}
+#else
+#ifdef _OSK
+{
+	register int f;
+
+	f = open(filename, S_IREAD | S_IFDIR);
+	if (f >= 0)
+		close(f);
+	isdir = (f >= 0);
+}
+#endif
+#endif
+	free(filename);
+	return (isdir);
+}
+
+/*
+ * Returns NULL if the file can be opened and
+ * is an ordinary file, otherwise an error message
+ * (if it cannot be opened or is a directory, etc.)
+ */
+	public char *
+bad_file(filename)
+	char *filename;
+{
+	register char *m = NULL;
+
+	filename = unquote_file(filename);
+	if (is_dir(filename))
+	{
+		static char is_dir[] = " is a directory";
+
+		m = (char *) ecalloc(strlen(filename) + sizeof(is_dir), 
+			sizeof(char));
+		strcpy(m, filename);
+		strcat(m, is_dir);
+	} else
+	{
+#if HAVE_STAT
+		int r;
+		struct stat statbuf;
+
+		r = stat(filename, &statbuf);
+		if (r < 0)
+		{
+			m = errno_message(filename);
+		} else if (force_open)
+		{
+			m = NULL;
+		} else if (!S_ISREG(statbuf.st_mode))
+		{
+			static char not_reg[] = " is not a regular file (use -f to see it)";
+			m = (char *) ecalloc(strlen(filename) + sizeof(not_reg),
+				sizeof(char));
+			strcpy(m, filename);
+			strcat(m, not_reg);
+		}
+#endif
+	}
+	free(filename);
+	return (m);
+}
+
+/*
+ * Return the size of a file, as cheaply as possible.
+ * In Unix, we can stat the file.
+ */
+	public POSITION
+filesize(f)
+	int f;
+{
+#if HAVE_STAT
+	struct stat statbuf;
+
+	if (fstat(f, &statbuf) >= 0)
+		return ((POSITION) statbuf.st_size);
+#else
+#ifdef _OSK
+	long size;
+
+	if ((size = (long) _gs_size(f)) >= 0)
+		return ((POSITION) size);
+#endif
+#endif
+	return (seek_filesize(f));
+}
+