X-Git-Url: http://repo.macrolet.net/gitweb/?a=blobdiff_plain;f=src%2Fcode%2Funix.lisp;h=19123d1f4e625f4134975e32050394f15cd01bf0;hb=80722c917cade18ab933fd313b13c56c6073ae01;hp=47500133391bc927f623b68cf59f16dcd5aa4909;hpb=dccfa0f4e378a267744c03b1416accdf9d888987;p=sbcl.git diff --git a/src/code/unix.lisp b/src/code/unix.lisp index 4750013..19123d1 100644 --- a/src/code/unix.lisp +++ b/src/code/unix.lisp @@ -91,8 +91,8 @@ ;;;; hacking the Unix environment (def-alien-routine ("getenv" posix-getenv) c-string - "Return the environment string \"name=value\" which corresponds to NAME, or - NIL if there is none." + "Return the \"value\" part of the environment string \"name=value\" which + corresponds to NAME, or NIL if there is none." (name c-string)) ;;; from stdio.h @@ -107,23 +107,11 @@ (/show0 "unix.lisp 220") -;;; FIXME: Isn't there some way to use a C wrapper to avoid this hand-copying? -(defconstant +max-s-long+ 2147483647) -(defconstant +max-u-long+ 4294967295) -(def-alien-type quad-t #+nil long-long #-nil (array long 2)) -(def-alien-type uquad-t #+nil unsigned-long-long - #-nil (array unsigned-long 2)) -(def-alien-type qaddr-t (* quad-t)) -(def-alien-type daddr-t int) -(def-alien-type caddr-t (* char)) -(def-alien-type swblk-t long) -(def-alien-type size-t unsigned-int) -(def-alien-type ssize-t int) - -;;; FIXME: We shouldn't hand-copy types from header files into Lisp like this -;;; unless we have extreme provocation. Reading directories is not extreme -;;; enough, since it doesn't need to be blindingly fast: we can just implement -;;; those functions in C as a wrapper layer. +;;; FIXME: We shouldn't hand-copy types from header files into Lisp +;;; like this unless we have extreme provocation. Reading directories +;;; is not extreme enough, since it doesn't need to be blindingly +;;; fast: we can just implement those functions in C as a wrapper +;;; layer. (def-alien-type fd-mask unsigned-long) (eval-when (:compile-toplevel :load-toplevel :execute) @@ -271,29 +259,49 @@ (values (deref fds 0) (deref fds 1)) (cast fds (* int))))) -;;; UNIX-CHDIR accepts a directory name and makes that the -;;; current working directory. -(defun unix-chdir (path) - (declare (type unix-pathname path)) - (void-syscall ("chdir" c-string) path)) - (defun unix-mkdir (name mode) (declare (type unix-pathname name) (type unix-file-mode mode)) (void-syscall ("mkdir" c-string int) name mode)) -;;; Return the current directory as a SIMPLE-STRING. -(defun unix-current-directory () - ;; FIXME: Gcc justifiably complains that getwd is dangerous and should - ;; not be used; especially with a hardwired 1024 buffer size, yecch. - ;; This should be rewritten to use getcwd(3), perhaps by writing - ;; a C service routine to do the actual call to getcwd(3) and check - ;; of return values. - (with-alien ((buf (array char 1024))) - (values (not (zerop (alien-funcall (extern-alien "getwd" - (function int (* char))) - (cast buf (* char))))) - (cast buf c-string)))) +;;; Return the Unix current directory as a SIMPLE-STRING, in the +;;; style returned by getcwd() (no trailing slash character). +(defun posix-getcwd () + ;; This implementation relies on a BSD/Linux extension to getcwd() + ;; behavior, automatically allocating memory when a null buffer + ;; pointer is used. On a system which doesn't support that + ;; extension, it'll have to be rewritten somehow. + #!-(or linux openbsd freebsd) (,stub,) + (let* ((raw-char-ptr (alien-funcall (extern-alien "getcwd" + (function (* char) + (* char) size-t)) + nil 0))) + (if (null-alien raw-char-ptr) + (simple-perror "getcwd") + (prog1 + (cast raw-char-ptr c-string) + (free-alien raw-char-ptr))))) + +;;; Return the Unix current directory as a SIMPLE-STRING terminated +;;; by a slash character. +(defun posix-getcwd/ () + (concatenate 'string (posix-getcwd) "/")) + +;;; Convert at the UNIX level from a possibly relative filename to +;;; an absolute filename. +;;; +;;; FIXME: Do we still need this even as we switch to +;;; *DEFAULT-PATHNAME-DEFAULTS*? I think maybe we do, since it seems +;;; to be valid for the user to set *DEFAULT-PATHNAME-DEFAULTS* to +;;; have a NIL directory component, and then this'd be the only way to +;;; interpret a relative directory specification. But I don't find the +;;; ANSI pathname documentation to be a model of clarity. Maybe +;;; someone who understands it better can take a look at this.. -- WHN +(defun unix-maybe-prepend-current-directory (name) + (declare (simple-string name)) + (if (and (> (length name) 0) (char= (schar name 0) #\/)) + name + (concatenate 'simple-string (posix-getcwd/) name))) ;;; Duplicate an existing file descriptor (given as the argument) and ;;; return it. If FD is not a valid file descriptor, NIL and an error @@ -315,20 +323,22 @@ ;;; Return the real user-id associated with the current process. (def-alien-routine ("getuid" unix-getuid) int) -;;; Invoke readlink(2) on the file name specified by the simple string -;;; PATH. Return up to two values: the contents of the symbolic link -;;; if the call is successful, or NIL and the Unix error number. +;;; Invoke readlink(2) on the file name specified by PATH. Return +;;; (VALUES LINKSTRING NIL) on success, or (VALUES NIL ERRNO) on +;;; failure. (defun unix-readlink (path) (declare (type unix-pathname path)) - (with-alien ((buf (array char 1024))) - (syscall ("readlink" c-string (* char) int) - (let ((string (make-string result))) - (sb!kernel:copy-from-system-area - (alien-sap buf) 0 - string (* sb!vm:vector-data-offset sb!vm:word-bits) - (* result sb!vm:byte-bits)) - string) - path (cast buf (* char)) 1024))) + (with-alien ((ptr (* char) + (alien-funcall (extern-alien + "wrapped_readlink" + (function (* char) c-string)) + path))) + (if (null-alien ptr) + (values nil (get-errno)) + (multiple-value-prog1 + (values (with-alien ((c-string c-string ptr)) c-string) + nil) + (free-alien ptr))))) ;;; UNIX-UNLINK accepts a name and deletes the directory entry for that ;;; name and the file if this is the last link. @@ -336,26 +346,6 @@ (declare (type unix-pathname name)) (void-syscall ("unlink" c-string) name)) -;;; Set the tty-process-group for the unix file-descriptor FD to PGRP. -;;; If not supplied, FD defaults to "/dev/tty". -(defun %set-tty-process-group (pgrp &optional fd) - (let ((old-sigs (unix-sigblock (sigmask :sigttou - :sigttin - :sigtstp - :sigchld)))) - (declare (type (unsigned-byte 32) old-sigs)) - (unwind-protect - (if fd - (tcsetpgrp fd pgrp) - (multiple-value-bind (tty-fd errno) (unix-open "/dev/tty" o_rdwr 0) - (cond (tty-fd - (multiple-value-prog1 - (tcsetpgrp tty-fd pgrp) - (unix-close tty-fd))) - (t - (values nil errno))))) - (unix-sigsetmask old-sigs)))) - ;;; Return the name of the host machine as a string. (defun unix-gethostname () (with-alien ((buf (array char 256))) @@ -387,8 +377,8 @@ #!-sb-fluid (declaim (inline unix-fast-getrusage)) (defun unix-fast-getrusage (who) (declare (values (member t) - (unsigned-byte 31) (mod 1000000) - (unsigned-byte 31) (mod 1000000))) + (unsigned-byte 31) (integer 0 1000000) + (unsigned-byte 31) (integer 0 1000000))) (with-alien ((usage (struct rusage))) (syscall* ("getrusage" int (* (struct rusage))) (values t @@ -434,11 +424,17 @@ timeout-secs &optional (timeout-usecs 0)) #!+sb-doc "Perform the UNIX select(2) system call." - (declare (type (integer 0 #.FD-SETSIZE) num-descriptors) + ;; FIXME: These DECLAREs don't belong at macroexpansion time. They + ;; should be done at runtime instead. Perhaps we could just redo + ;; UNIX-FAST-SELECT as an inline function, and then all the + ;; declarations would work nicely. + #| + (declare (type (integer 0 #.fd-setsize) num-descriptors) (type (or (alien (* (struct fd-set))) null) read-fds write-fds exception-fds) (type (or null (unsigned-byte 31)) timeout-secs) - (type (unsigned-byte 31) timeout-usecs) ) + (type (unsigned-byte 31) timeout-usecs)) + |# ;; FIXME: CMU CL had ;; (optimize (speed 3) (safety 0) (inhibit-warnings 3)) ;; in the declarations above. If they're important, they should @@ -693,96 +689,71 @@ ((eql kind s-iflnk) :link) (t :special)))))) -(defun unix-maybe-prepend-current-directory (name) - (declare (simple-string name)) - (if (and (> (length name) 0) (char= (schar name 0) #\/)) - name - (multiple-value-bind (win dir) (unix-current-directory) - (if win - (concatenate 'simple-string dir "/" name) - name)))) - -;;; Return the pathname with all symbolic links resolved. -;;; -;;; FIXME: Could we just use Unix readlink(2) instead? +;;; Is the Unix pathname PATHNAME relative, instead of absolute? (E.g. +;;; "passwd" or "etc/passwd" instead of "/etc/passwd"?) +(defun relative-unix-pathname? (pathname) + (declare (type simple-string pathname)) + (or (zerop (length pathname)) + (char/= (schar pathname 0) #\/))) + +;;; Return PATHNAME with all symbolic links resolved. PATHNAME should +;;; already be a complete absolute Unix pathname, since at least in +;;; sbcl-0.6.12.36 we're called only from TRUENAME, and only after +;;; paths have been converted to absolute paths, so we don't need to +;;; try to handle any more generality than that. (defun unix-resolve-links (pathname) - (declare (simple-string pathname)) - (let ((len (length pathname)) - (pending pathname)) - (declare (fixnum len) (simple-string pending)) - (if (zerop len) - pathname - (let ((result (make-string 1024 :initial-element (code-char 0))) - (fill-ptr 0) - (name-start 0)) - (loop - (let* ((name-end (or (position #\/ pending :start name-start) len)) - (new-fill-ptr (+ fill-ptr (- name-end name-start)))) - (replace result pending - :start1 fill-ptr - :end1 new-fill-ptr - :start2 name-start - :end2 name-end) - (let ((kind (unix-file-kind (if (zerop name-end) "/" result) t))) - (unless kind (return nil)) - (cond ((eq kind :link) - (multiple-value-bind (link err) (unix-readlink result) - (unless link - (error 'simple-file-error - :pathname pathname - :format-control - "~@" - :format-arguments (list (subseq - result 0 fill-ptr) - (strerror err)))) - (cond ((or (zerop (length link)) - (char/= (schar link 0) #\/)) - ;; It's a relative link. - (fill result (code-char 0) - :start fill-ptr - :end new-fill-ptr)) - ((string= result "/../" :end1 4) - ;; It's across the super-root. - (let ((slash (or (position #\/ result :start 4) - 0))) - (fill result (code-char 0) - :start slash - :end new-fill-ptr) - (setf fill-ptr slash))) - (t - ;; It's absolute. - (and (> (length link) 0) - (char= (schar link 0) #\/)) - (fill result (code-char 0) :end new-fill-ptr) - (setf fill-ptr 0))) - (setf pending - (if (= name-end len) - link - (concatenate 'simple-string - link - (subseq pending name-end)))) - (setf len (length pending)) - (setf name-start 0))) - ((= name-end len) - (return (subseq result 0 new-fill-ptr))) - ((eq kind :directory) - (setf (schar result new-fill-ptr) #\/) - (setf fill-ptr (1+ new-fill-ptr)) - (setf name-start (1+ name-end))) - (t - (return nil)))))))))) + (declare (type simple-string pathname)) + (aver (not (relative-unix-pathname? pathname))) + (/show "entering UNIX-RESOLVE-LINKS") + (loop with previous-pathnames = nil do + (/show pathname previous-pathnames) + (let ((link (unix-readlink pathname))) + (/show link) + ;; Unlike the old CMU CL code, we handle a broken symlink by + ;; returning the link itself. That way, CL:TRUENAME on a + ;; broken link returns the link itself, so that CL:DIRECTORY + ;; can return broken links, so that even without + ;; Unix-specific extensions to do interesting things with + ;; them, at least Lisp programs can see them and, if + ;; necessary, delete them. (This is handy e.g. when your + ;; managed-by-Lisp directories are visited by Emacs, which + ;; creates broken links as notes to itself.) + (if (null link) + (return pathname) + (let ((new-pathname + (unix-simplify-pathname + (if (relative-unix-pathname? link) + (let* ((dir-len (1+ (position #\/ + pathname + :from-end t))) + (dir (subseq pathname 0 dir-len))) + (/show dir) + (concatenate 'string dir link)) + link)))) + (if (unix-file-kind new-pathname) + (setf pathname new-pathname) + (return pathname))))) + ;; To generalize the principle that even if portable Lisp code + ;; can't do anything interesting with a broken symlink, at + ;; least it should be able to see and delete it, when we + ;; detect a cyclic link, we return the link itself. (So even + ;; though portable Lisp code can't do anything interesting + ;; with a cyclic link, at least it can see it and delete it.) + (if (member pathname previous-pathnames :test #'string=) + (return pathname) + (push pathname previous-pathnames)))) (defun unix-simplify-pathname (src) - (declare (simple-string src)) + (declare (type simple-string src)) (let* ((src-len (length src)) (dst (make-string src-len)) (dst-len 0) (dots 0) (last-slash nil)) (macrolet ((deposit (char) - `(progn - (setf (schar dst dst-len) ,char) - (incf dst-len)))) + `(progn + (setf (schar dst dst-len) ,char) + (incf dst-len)))) (dotimes (src-index src-len) (let ((char (schar src src-index))) (cond ((char= char #\.) @@ -792,12 +763,12 @@ ((char= char #\/) (case dots (0 - ;; Either ``/...' or ``...//...' + ;; either ``/...' or ``...//...' (unless last-slash (setf last-slash dst-len) (deposit char))) (1 - ;; Either ``./...'' or ``..././...'' + ;; either ``./...'' or ``..././...'' (decf dst-len)) (2 ;; We've found .. @@ -825,7 +796,7 @@ (setf last-slash dst-len) (deposit char)))) (t - ;; Something other than a dot between slashes. + ;; something other than a dot between slashes (setf last-slash dst-len) (deposit char))) (setf dots 0))