/* $Id$ Part of SWI-Prolog Author: Jan Wielemaker E-mail: J.Wielemaker@uva.nl WWW: http://www.swi-prolog.org Copyright (C): 1985-2008, University of Amsterdam This library is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation; either version 2.1 of the License, or (at your option) any later version. This library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details. You should have received a copy of the GNU Lesser General Public License along with this library; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */ #include "pl-incl.h" #include /**** stuff from uxnt ****/ #ifdef O_XOS #include "uxnt/uxnt.h" #endif #ifdef HAVE_SYS_STAT_H #include #endif #ifdef O_XOS #define statstruct struct _stat #else #define statstruct struct stat #define statfunc stat #endif #undef LD #define LD LOCAL_LD /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - General file operations and binding to Prolog - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */ /******************************* * OS STUFF * *******************************/ /** time_t LastModifiedFile(const char *file) Return the last modification time of file as a POSIX timestamp. Returns (time_t)-1 on failure. */ time_t LastModifiedFile(const char *file) { char tmp[MAXPATHLEN]; statstruct buf; if ( statfunc(OsPath(file, tmp), &buf) < 0 ) return (time_t)-1; return buf.st_mtime; } /** static int64_t SizeFile(const char *path) Return the size of the file path in bytes. Returns -1 if the file cannot be accessed. */ static int64_t SizeFile(const char *path) { char tmp[MAXPATHLEN]; statstruct buf; if ( statfunc(OsPath(path, tmp), &buf) < 0 ) return -1; return buf.st_size; } /** int AccessFile(const char *path, int mode) TRUE if path can be accessed in the specified modes. Mode is a bitwise or created from one or more of the constants ACCESS_EXIST, ACCESS_READ, ACCESS_WRITE and ACCESS_EXECUTE. */ #ifndef F_OK #define F_OK 0 #endif int AccessFile(const char *path, int mode) { char tmp[MAXPATHLEN]; #ifdef HAVE_ACCESS int m = 0; if ( mode == ACCESS_EXIST ) m = F_OK; else { if ( mode & ACCESS_READ ) m |= R_OK; if ( mode & ACCESS_WRITE ) m |= W_OK; #ifdef X_OK if ( mode & ACCESS_EXECUTE ) m |= X_OK; #endif } return access(OsPath(path, tmp), m) == 0 ? TRUE : FALSE; #else #error "No implementation for AccessFile()" #endif } int ExistsFile(const char *path) { #ifdef O_XOS return _xos_exists(path, _XOS_FILE); #else char tmp[MAXPATHLEN]; statstruct buf; if ( statfunc(OsPath(path, tmp), &buf) == -1 || !S_ISREG(buf.st_mode) ) { DEBUG(2, perror(tmp)); return FALSE; } return TRUE; #endif } int ExistsDirectory(const char *path) { #ifdef O_XOS return _xos_exists(path, _XOS_DIR); #else char tmp[MAXPATHLEN]; char *ospath = OsPath(path, tmp); statstruct buf; if ( statfunc(ospath, &buf) < 0 ) return FALSE; if ( S_ISDIR(buf.st_mode) ) return TRUE; return FALSE; #endif /*O_XOS*/ } static char * ReadLink(const char *f, char *buf) { #ifdef HAVE_READLINK int n; if ( (n=readlink(f, buf, MAXPATHLEN-1)) > 0 ) { buf[n] = EOS; return buf; } #endif return NULL; } static char * DeRefLink1(const char *f, char *lbuf) { char buf[MAXPATHLEN]; char *l; if ( (l=ReadLink(f, buf)) ) { if ( l[0] == '/' ) /* absolute path */ { strcpy(lbuf, buf); return lbuf; } else { char *q; strcpy(lbuf, f); q = &lbuf[strlen(lbuf)]; while(q>lbuf && q[-1] != '/') q--; strcpy(q, l); canoniseFileName(lbuf); return lbuf; } } return NULL; } /** char *DeRefLink(const char *link, char *buf) Dereference a symbolic link, returning its final destination. The returned filename is canonical (i.e., references to ./ and ../ are removed). Returns NULL if more than 20 links have been followed. */ char * DeRefLink(const char *link, char *buf) { char tmp[MAXPATHLEN]; char *f; int n = 20; /* avoid loop! */ while((f=DeRefLink1(link, tmp)) && n-- > 0) link = f; if ( n > 0 ) { strcpy(buf, link); return buf; } else return NULL; } static int SameFile(const char *f1, const char *f2) { GET_LD if ( truePrologFlag(PLFLAG_FILE_CASE) ) { if ( streq(f1, f2) ) return TRUE; } else { if ( strcasecmp(f1, f2) == 0 ) return TRUE; } #ifdef __unix__ /* doesn't work on most not Unix's */ { statstruct buf1; statstruct buf2; char tmp[MAXPATHLEN]; if ( statfunc(OsPath(f1, tmp), &buf1) != 0 || statfunc(OsPath(f2, tmp), &buf2) != 0 ) return FALSE; if ( buf1.st_ino == buf2.st_ino && buf1.st_dev == buf2.st_dev ) return TRUE; } #endif #ifdef O_XOS return _xos_same_file(f1, f2); #endif /*O_XOS*/ /* Amazing! There is no simple way to check two files for identity. */ /* stat() and fstat() both return dummy values for inode and device. */ /* this is fine as OS'es not supporting symbolic links don't need this */ return FALSE; } /** int RemoveFile(const char *path) Remove a file from the filesystem. Returns TRUE on success and FALSE otherwise. */ int RemoveFile(const char *path) { char tmp[MAXPATHLEN]; #ifdef HAVE_REMOVE return remove(OsPath(path, tmp)) == 0 ? TRUE : FALSE; #else return unlink(OsPath(path, tmp)) == 0 ? TRUE : FALSE; #endif } static int RenameFile(const char *old, const char *new) { char oldbuf[MAXPATHLEN]; char newbuf[MAXPATHLEN]; char *osold, *osnew; osold = OsPath(old, oldbuf); osnew = OsPath(new, newbuf); #ifdef HAVE_RENAME return rename(osold, osnew) == 0 ? TRUE : FALSE; #else { int rval; unlink(osnew); if ( (rval = link(osold, osnew)) == 0 && (rval = unlink(osold)) != 0) unlink(osnew); if ( rval == 0 ) return TRUE; return FALSE; } #endif /*HAVE_RENAME*/ } static int MarkExecutable(const char *name) { #if (defined(HAVE_STAT) && defined(HAVE_CHMOD)) || defined(__unix__) statstruct buf; mode_t um; um = umask(0777); umask(um); if ( statfunc(name, &buf) == -1 ) { GET_LD term_t file = PL_new_term_ref(); PL_put_atom_chars(file, name); return PL_error(NULL, 0, OsError(), ERR_FILE_OPERATION, ATOM_stat, ATOM_file, file); } if ( (buf.st_mode & 0111) == (~um & 0111) ) return TRUE; buf.st_mode |= 0111 & ~um; if ( chmod(name, buf.st_mode) == -1 ) { GET_LD term_t file = PL_new_term_ref(); PL_put_atom_chars(file, name); return PL_error(NULL, 0, OsError(), ERR_FILE_OPERATION, ATOM_chmod, ATOM_file, file); } #endif /* defined(HAVE_STAT) && defined(HAVE_CHMOD) */ return TRUE; } /******************************** * FIND FILES FROM C * *********************************/ static int unifyTime(term_t t, time_t time) { return PL_unify_float(t, (double)time); } static int add_option(term_t options, functor_t f, atom_t val) { GET_LD term_t head; if ( (head=PL_new_term_ref()) && PL_unify_list(options, head, options) && PL_unify_term(head, PL_FUNCTOR, f, PL_ATOM, val) ) { PL_reset_term_refs(head); return TRUE; } return FALSE; } #define CVT_FILENAME (CVT_ATOM|CVT_STRING|CVT_LIST) int PL_get_file_name(term_t n, char **namep, int flags) { GET_LD char *name; char tmp[MAXPATHLEN]; char ospath[MAXPATHLEN]; if ( flags & PL_FILE_SEARCH ) { fid_t fid; if ( (fid = PL_open_foreign_frame()) ) { predicate_t pred = PL_predicate("absolute_file_name", 3, "system"); term_t av = PL_new_term_refs(3); term_t options = PL_copy_term_ref(av+2); int rc = TRUE; int cflags = ((flags&PL_FILE_NOERRORS) ? PL_Q_CATCH_EXCEPTION : PL_Q_PASS_EXCEPTION); PL_put_term(av+0, n); if ( rc && flags & PL_FILE_EXIST ) rc = add_option(options, FUNCTOR_access1, ATOM_exist); if ( rc && flags & PL_FILE_READ ) rc = add_option(options, FUNCTOR_access1, ATOM_read); if ( rc && flags & PL_FILE_WRITE ) rc = add_option(options, FUNCTOR_access1, ATOM_write); if ( rc && flags & PL_FILE_EXECUTE ) rc = add_option(options, FUNCTOR_access1, ATOM_execute); if ( rc ) rc = PL_unify_nil(options); if ( rc ) rc = PL_call_predicate(NULL, cflags, pred, av); if ( rc ) rc = PL_get_chars_ex(av+1, namep, CVT_ATOMIC|BUF_RING|REP_FN); PL_discard_foreign_frame(fid); return rc; } return FALSE; } if ( flags & PL_FILE_NOERRORS ) { if ( !PL_get_chars(n, &name, CVT_FILENAME|REP_FN) ) return FALSE; } else { if ( !PL_get_chars_ex(n, &name, CVT_FILENAME|REP_FN) ) return FALSE; } if ( truePrologFlag(PLFLAG_FILEVARS) ) { if ( !(name = ExpandOneFile(name, tmp)) ) return FALSE; } if ( !(flags & PL_FILE_NOERRORS) ) { atom_t op = 0; if ( (flags&PL_FILE_READ) && !AccessFile(name, ACCESS_READ) ) op = ATOM_read; if ( !op && (flags&PL_FILE_WRITE) && !AccessFile(name, ACCESS_WRITE) ) op = ATOM_write; if ( !op && (flags&PL_FILE_EXECUTE) && !AccessFile(name, ACCESS_EXECUTE) ) op = ATOM_execute; if ( op ) return PL_error(NULL, 0, NULL, ERR_PERMISSION, ATOM_file, op, n); if ( (flags & PL_FILE_EXIST) && !AccessFile(name, ACCESS_EXIST) ) return PL_error(NULL, 0, NULL, ERR_EXISTENCE, ATOM_file, n); } if ( flags & PL_FILE_ABSOLUTE ) { if ( !(name = AbsoluteFile(name, tmp)) ) return FALSE; } if ( flags & PL_FILE_OSPATH ) { if ( !(name = OsPath(name, ospath)) ) return FALSE; } *namep = buffer_string(name, BUF_RING); return TRUE; } /******************************* * QUERY FILES * *******************************/ static PRED_IMPL("time_file", 2, time_file, 0) { char *fn; if ( PL_get_file_name(A1, &fn, 0) ) { time_t time; if ( (time = LastModifiedFile(fn)) == (time_t)-1 ) return PL_error(NULL, 0, NULL, ERR_FILE_OPERATION, ATOM_time, ATOM_file, A1); return unifyTime(A2, time); } return FALSE; } static PRED_IMPL("size_file", 2, size_file, 0) { char *n; if ( PL_get_file_name(A1, &n, 0) ) { int64_t size; if ( (size = SizeFile(n)) < 0 ) return PL_error("size_file", 2, OsError(), ERR_FILE_OPERATION, ATOM_size, ATOM_file, A1); return PL_unify_int64(A2, size); } return FALSE; } static PRED_IMPL("access_file", 2, access_file, 0) { PRED_LD char *n; int md; atom_t m; term_t name = A1; term_t mode = A2; if ( !PL_get_atom(mode, &m) ) return PL_error("access_file", 2, NULL, ERR_TYPE, ATOM_atom, mode); if ( !PL_get_file_name(name, &n, 0) ) return FALSE; if ( m == ATOM_none ) return TRUE; if ( m == ATOM_write || m == ATOM_append ) md = ACCESS_WRITE; else if ( m == ATOM_read ) md = ACCESS_READ; else if ( m == ATOM_execute ) md = ACCESS_EXECUTE; else if ( m == ATOM_exist ) md = ACCESS_EXIST; else return PL_error("access_file", 2, NULL, ERR_DOMAIN, ATOM_io_mode, mode); if ( AccessFile(n, md) ) return TRUE; if ( md == ACCESS_WRITE && !AccessFile(n, ACCESS_EXIST) ) { char tmp[MAXPATHLEN]; char *dir = DirName(n, tmp); if ( dir[0] ) { if ( !ExistsDirectory(dir) ) return FALSE; } if ( AccessFile(dir[0] ? dir : ".", md) ) return TRUE; } return FALSE; } static PRED_IMPL("read_link", 3, read_link, 0) { char *n, *l, *t; char buf[MAXPATHLEN]; term_t file = A1; term_t link = A2; term_t to = A3; if ( !PL_get_file_name(file, &n, 0) ) return FALSE; if ( (l = ReadLink(n, buf)) && PL_unify_atom_chars(link, l) && (t = DeRefLink(n, buf)) && PL_unify_atom_chars(to, t) ) return TRUE; return FALSE; } static PRED_IMPL("exists_file", 1, exists_file, 0) { char *n; if ( !PL_get_file_name(A1, &n, 0) ) return FALSE; return ExistsFile(n); } static PRED_IMPL("exists_directory", 1, exists_directory, 0) { char *n; if ( !PL_get_file_name(A1, &n, 0) ) return FALSE; return ExistsDirectory(n); } static PRED_IMPL("is_absolute_file_name", 1, is_absolute_file_name, 0) { char *n; if ( PL_get_file_name(A1, &n, 0) && IsAbsolutePath(n) ) return TRUE; return FALSE; } static PRED_IMPL("same_file", 2, same_file, 0) { char *n1, *n2; if ( PL_get_file_name(A1, &n1, 0) && PL_get_file_name(A2, &n2, 0) ) return SameFile(n1, n2); return FALSE; } static PRED_IMPL("file_base_name", 2, file_base_name, 0) { char *n; if ( !PL_get_chars_ex(A1, &n, CVT_ALL|REP_FN) ) return FALSE; return PL_unify_chars(A2, PL_ATOM|REP_FN, -1, BaseName(n)); } static PRED_IMPL("file_directory_name", 2, file_directory_name, 0) { char *n; char tmp[MAXPATHLEN]; if ( !PL_get_chars_ex(A1, &n, CVT_ALL|REP_FN) ) return FALSE; return PL_unify_chars(A2, PL_ATOM|REP_FN, -1, DirName(n, tmp)); } /******************************* * TEMPORARY FILES * *******************************/ static PRED_IMPL("tmp_file", 2, tmp_file, 0) { PRED_LD char *n; term_t base = A1; term_t name = A2; if ( !PL_get_chars(base, &n, CVT_ALL) ) return PL_error("tmp_file", 2, NULL, ERR_TYPE, ATOM_atom, base); return PL_unify_atom(name, TemporaryFile(n, NULL)); } /** tmp_file_stream(+Mode, -File, -Stream) */ static PRED_IMPL("tmp_file_stream", 3, tmp_file_stream, 0) { PRED_LD atom_t fn; int fd; IOENC enc; atom_t encoding; const char *mode; if ( !PL_get_atom_ex(A1, &encoding) ) return FALSE; if ( (enc = atom_to_encoding(encoding)) == ENC_UNKNOWN ) { if ( encoding == ATOM_binary ) { enc = ENC_OCTET; mode = "wb"; } else { return PL_error(NULL, 0, NULL, ERR_DOMAIN, ATOM_encoding, A1); } } else { mode = "w"; } if ( (fn=TemporaryFile("", &fd)) ) { IOSTREAM *s; if ( !PL_unify_atom(A2, fn) ) { close(fd); return PL_error(NULL, 0, NULL, ERR_MUST_BE_VAR, 2); } s = Sfdopen(fd, mode); s->encoding = enc; return PL_unify_stream(A3, s); } else { return PL_error(NULL, 0, NULL, ERR_RESOURCE, ATOM_temporary_files); } } /******************************* * CHANGE FILESYSTEM * *******************************/ static PRED_IMPL("delete_file", 1, delete_file, 0) { PRED_LD char *n; atom_t aname; if ( PL_get_atom(A1, &aname) && DeleteTemporaryFile(aname) ) return TRUE; if ( !PL_get_file_name(A1, &n, 0) ) return FALSE; if ( RemoveFile(n) ) return TRUE; return PL_error(NULL, 0, MSG_ERRNO, ERR_FILE_OPERATION, ATOM_delete, ATOM_file, A1); } static PRED_IMPL("delete_directory", 1, delete_directory, 0) { char *n; if ( !PL_get_file_name(A1, &n, 0) ) return FALSE; if ( rmdir(n) == 0 ) return TRUE; else return PL_error(NULL, 0, MSG_ERRNO, ERR_FILE_OPERATION, ATOM_delete, ATOM_directory, A1); } static PRED_IMPL("make_directory", 1, make_directory, 0) { char *n; if ( !PL_get_file_name(A1, &n, 0) ) return FALSE; if ( mkdir(n, 0777) == 0 ) return TRUE; else return PL_error(NULL, 0, MSG_ERRNO, ERR_FILE_OPERATION, ATOM_create, ATOM_directory, A1); } static PRED_IMPL("rename_file", 2, rename_file, 0) { PRED_LD char *o, *n; term_t old = A1; term_t new = A2; if ( PL_get_file_name(old, &o, 0) && PL_get_file_name(new, &n, 0) ) { if ( SameFile(o, n) ) { if ( truePrologFlag(PLFLAG_FILEERRORS) ) return PL_error("rename_file", 2, "same file", ERR_PERMISSION, ATOM_rename, ATOM_file, old); return FALSE; } if ( RenameFile(o, n) ) return TRUE; if ( truePrologFlag(PLFLAG_FILEERRORS) ) return PL_error("rename_file", 2, OsError(), ERR_FILE_OPERATION, ATOM_rename, ATOM_file, old); return FALSE; } return FALSE; } static PRED_IMPL("$absolute_file_name", 2, absolute_file_name, 0) { char *n; char tmp[MAXPATHLEN]; term_t name = A1; term_t expanded = A2; if ( PL_get_file_name(name, &n, 0) && (n = AbsoluteFile(n, tmp)) ) return PL_unify_chars(expanded, PL_ATOM|REP_FN, -1, n); return FALSE; } static PRED_IMPL("working_directory", 2, working_directory, 0) { PRED_LD const char *wd; term_t old = A1; term_t new = A2; if ( !(wd = PL_cwd()) ) return FALSE; if ( PL_unify_chars(old, PL_ATOM|REP_FN, -1, wd) ) { if ( PL_compare(old, new) != 0 ) { char *n; if ( PL_get_file_name(new, &n, 0) ) { if ( ChDir(n) ) return TRUE; if ( truePrologFlag(PLFLAG_FILEERRORS) ) return PL_error(NULL, 0, NULL, ERR_FILE_OPERATION, ATOM_chdir, ATOM_directory, new); return FALSE; } } return TRUE; } return FALSE; } static int has_extension(const char *name, const char *ext) { GET_LD const char *s = name + strlen(name); if ( ext[0] == EOS ) return TRUE; while(*s != '.' && *s != '/' && s > name) s--; if ( *s == '.' && s > name && s[-1] != '/' ) { if ( ext[0] == '.' ) ext++; if ( truePrologFlag(PLFLAG_FILE_CASE) ) return strcmp(&s[1], ext) == 0; else return strcasecmp(&s[1], ext) == 0; } return FALSE; } static int name_too_long(void) { return PL_error(NULL, 0, NULL, ERR_REPRESENTATION, ATOM_max_path_length); } static PRED_IMPL("file_name_extension", 3, file_name_extension, 0) { PRED_LD char *b = NULL, *e = NULL, *f; char buf[MAXPATHLEN]; term_t base = A1; term_t ext = A2; term_t full = A3; if ( !PL_is_variable(full) ) { if ( PL_get_chars(full, &f, CVT_ALL|CVT_EXCEPTION|REP_FN) ) { char *s = f + strlen(f); /* ?base, ?ext, +full */ while(*s != '.' && *s != '/' && s > f) s--; if ( *s == '.' ) { if ( PL_get_chars(ext, &e, CVT_ALL|REP_FN) ) { if ( e[0] == '.' ) e++; if ( truePrologFlag(PLFLAG_FILE_CASE) ) { TRY(strcmp(&s[1], e) == 0); } else { TRY(strcasecmp(&s[1], e) == 0); } } else { TRY(PL_unify_chars(ext, PL_ATOM|REP_FN, -1, &s[1])); } if ( s-f > MAXPATHLEN ) return name_too_long(); strncpy(buf, f, s-f); buf[s-f] = EOS; return PL_unify_chars(base, PL_ATOM|REP_FN, -1, buf); } if ( PL_unify_atom_chars(ext, "") && PL_unify(full, base) ) PL_succeed; } PL_fail; } if ( PL_get_chars_ex(base, &b, CVT_ALL|BUF_RING|REP_FN) && PL_get_chars_ex(ext, &e, CVT_ALL|REP_FN) ) { char *s; if ( e[0] == '.' ) /* +Base, +Extension, -full */ e++; if ( has_extension(b, e) ) return PL_unify(base, full); if ( strlen(b) + 1 + strlen(e) + 1 > MAXPATHLEN ) return name_too_long(); strcpy(buf, b); s = buf + strlen(buf); *s++ = '.'; strcpy(s, e); return PL_unify_chars(full, PL_ATOM|REP_FN, -1, buf); } else return FALSE; } static PRED_IMPL("prolog_to_os_filename", 2, prolog_to_os_filename, 0) { PRED_LD term_t pl = A1; term_t os = A2; #ifdef O_XOS wchar_t *wn; if ( !PL_is_variable(pl) ) { char *n; wchar_t buf[MAXPATHLEN]; if ( PL_get_chars_ex(pl, &n, CVT_ALL|REP_UTF8) ) { if ( !_xos_os_filenameW(n, buf, MAXPATHLEN) ) return name_too_long(); return PL_unify_wchars(os, PL_ATOM, -1, buf); } return FALSE; } if ( PL_get_wchars(os, NULL, &wn, CVT_ALL) ) { wchar_t lbuf[MAXPATHLEN]; char buf[MAXPATHLEN]; _xos_long_file_nameW(wn, lbuf, MAXPATHLEN); _xos_canonical_filenameW(lbuf, buf, MAXPATHLEN, 0); return PL_unify_chars(pl, PL_ATOM|REP_UTF8, -1, buf); } return PL_error(NULL, 0, NULL, ERR_TYPE, ATOM_atom, pl); #else /*O_XOS*/ return PL_unify(pl, os); #endif /*O_XOS*/ } static PRED_IMPL("mark_executable", 1, mark_executable, 0) { char *name; if ( !PL_get_file_name(A1, &name, 0) ) return PL_error(NULL, 0, NULL, ERR_DOMAIN, ATOM_source_sink, A1); return MarkExecutable(name); } /******************************* * INIT * *******************************/ void initFiles(void) { } /******************************* * PUBLISH PREDICATES * *******************************/ BeginPredDefs(files) PRED_DEF("working_directory", 2, working_directory, 0) PRED_DEF("access_file", 2, access_file, 0) PRED_DEF("time_file", 2, time_file, 0) PRED_DEF("size_file", 2, size_file, 0) PRED_DEF("read_link", 3, read_link, 0) PRED_DEF("exists_file", 1, exists_file, 0) PRED_DEF("exists_directory", 1, exists_directory, 0) PRED_DEF("tmp_file", 2, tmp_file, 0) PRED_DEF("tmp_file_stream", 3, tmp_file_stream, 0) PRED_DEF("delete_file", 1, delete_file, 0) PRED_DEF("delete_directory", 1, delete_directory, 0) PRED_DEF("make_directory", 1, make_directory, 0) PRED_DEF("same_file", 2, same_file, 0) PRED_DEF("rename_file", 2, rename_file, 0) PRED_DEF("is_absolute_file_name", 1, is_absolute_file_name, 0) PRED_DEF("file_base_name", 2, file_base_name, 0) PRED_DEF("file_directory_name", 2, file_directory_name, 0) PRED_DEF("file_name_extension", 3, file_name_extension, 0) PRED_DEF("prolog_to_os_filename", 2, prolog_to_os_filename, 0) PRED_DEF("$mark_executable", 1, mark_executable, 0) PRED_DEF("$absolute_file_name", 2, absolute_file_name, 0) EndPredDefs