X-Git-Url: http://repo.macrolet.net/gitweb/?a=blobdiff_plain;ds=sidebyside;f=src%2Fcode%2Funix.lisp;h=b1193bf7fec735e4260ac7ec50590293d4797e7d;hb=d2241edb01a6dad8a7bc1107d28d0873f5f8d83e;hp=f39dd9735b18bc987297dc4d960b9d886034ac90;hpb=dfa55a883f94470267b626dae77ce7e7dfac3df6;p=sbcl.git diff --git a/src/code/unix.lisp b/src/code/unix.lisp index f39dd97..b1193bf 100644 --- a/src/code/unix.lisp +++ b/src/code/unix.lisp @@ -90,9 +90,9 @@ ;;;; 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." +(define-alien-routine ("getenv" posix-getenv) c-string + "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 @@ -107,29 +107,17 @@ (/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. -(def-alien-type fd-mask unsigned-long) +;;; 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. +(define-alien-type fd-mask unsigned-long) (eval-when (:compile-toplevel :load-toplevel :execute) (defconstant fd-setsize 1024)) -(def-alien-type nil +(define-alien-type nil (struct fd-set (fds-bits (array fd-mask #.(/ fd-setsize 32))))) @@ -164,7 +152,7 @@ ;; A time value that is accurate to the nearest ;; microsecond but also has a range of years. -(def-alien-type nil +(define-alien-type nil (struct timeval (tv-sec time-t) ; seconds (tv-usec time-t))) ; and microseconds @@ -175,7 +163,7 @@ (defconstant rusage_children -1) ; terminated child processes (defconstant rusage_both -2) -(def-alien-type nil +(define-alien-type nil (struct rusage (ru-utime (struct timeval)) ; user time used (ru-stime (struct timeval)) ; system time used. @@ -194,35 +182,6 @@ (ru-nvcsw long) ; voluntary context switches (ru-nivcsw long))) ; involuntary context switches - -;;;; runtime/stat-wrapper.h - -;;; this looks like "struct stat" according to stat(2). It may not -;;; correspond to the real in-memory stat structure that the syscall -;;; uses, and if it doesn't, shouldn't. Linux in particular is packed -;;; full of stat macros, so we do this stuff in runtime/stat-wrapper.c - -;;; Note that st-dev is a long, not a dev-t. This is because dev-t on -;;; linux 32 bit archs is a 64 bit quantity, but alien doesn's support -;;; those. We don't actually access that field anywhere, though, so until -;;; we can get 64 bit alien support it'll do - -(def-alien-type nil - (struct stat - (st-dev unsigned-long) ;would be dev-t in a real stat - (st-ino ino-t) - (st-mode mode-t) - (st-nlink nlink-t) - (st-uid uid-t) - (st-gid gid-t) - (st-rdev unsigned-long) ;ditto - (st-size off-t) - (st-blksize unsigned-long) - (st-blocks unsigned-long) - (st-atime time-t) - (st-mtime time-t) - (st-ctime time-t))) - ;;;; unistd.h ;;; Given a file path (a string) and one of four constant modes, @@ -300,24 +259,67 @@ (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)) - -;;; 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)))) +(defun unix-mkdir (name mode) + (declare (type unix-pathname name) + (type unix-file-mode mode)) + (void-syscall ("mkdir" c-string int) name mode)) + +;;; Given a C char* pointer allocated by malloc(), free it and return a +;;; corresponding Lisp string (or return NIL if the pointer is a C NULL). +(defun newcharstar-string (newcharstar) + (declare (type (alien (* char)) newcharstar)) + (if (null-alien newcharstar) + nil + (prog1 + (cast newcharstar c-string) + (free-alien newcharstar)))) + +;;; 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. + ;; + ;; SunOS and OSF/1 provide almost as useful an extension: if given a null + ;; buffer pointer, it will automatically allocate size space. The + ;; KLUDGE in this solution arises because we have just read off + ;; PATH_MAX+1 from the Solaris header files and stuck it in here as + ;; a constant. Going the grovel_headers route doesn't seem to be + ;; helpful, either, as Solaris doesn't export PATH_MAX from + ;; unistd.h. + #!-(or linux openbsd freebsd sunos osf1) (,stub,) + #!+(or linux openbsd freebsd sunos osf1) + (or (newcharstar-string (alien-funcall (extern-alien "getcwd" + (function (* char) + (* char) + size-t)) + nil + #!+(or linux openbsd freebsd) 0 + #!+(or sunos osf1) 1025)) + (simple-perror "getcwd"))) + +;;; 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 @@ -334,25 +336,42 @@ (void-syscall ("exit" int) code)) ;;; Return the process id of the current process. -(def-alien-routine ("getpid" unix-getpid) int) - -;;; 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. +(define-alien-routine ("getpid" unix-getpid) int) + +;;; Return the real user id associated with the current process. +(define-alien-routine ("getuid" unix-getuid) int) + +;;; Translate a user id into a login name. +(defun uid-username (uid) + (or (newcharstar-string (alien-funcall (extern-alien "uid_username" + (function (* char) int)) + uid)) + (error "found no match for Unix uid=~S" uid))) + +;;; Return the namestring of the home directory, being careful to +;;; include a trailing #\/ +(defun uid-homedir (uid) + (or (newcharstar-string (alien-funcall (extern-alien "uid_homedir" + (function (* char) int)) + uid)) + (error "failed to resolve home directory for Unix uid=~S" uid))) + +;;; 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. @@ -360,26 +379,6 @@ (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))) @@ -406,13 +405,14 @@ ;;; FIXME: All we seem to need is the RUSAGE_SELF version of this. ;;; -;;; Like getrusage(2), but return only the system and user time, -;;; and return the seconds and microseconds as separate values. +;;; This is like getrusage(2), except it returns only the system and +;;; user time, and returns the seconds and microseconds as separate +;;; values. #!-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 @@ -453,30 +453,29 @@ ;;;; sys/select.h -(defmacro unix-fast-select (num-descriptors - read-fds write-fds exception-fds - timeout-secs &optional (timeout-usecs 0)) - #!+sb-doc - "Perform the UNIX select(2) system call." - (declare (type (integer 0 #.FD-SETSIZE) num-descriptors) +;;;; FIXME: Why have both UNIX-SELECT and UNIX-FAST-SELECT? + +;;; Perform the UNIX select(2) system call. +(declaim (inline unix-fast-select)) ; (used to be a macro in CMU CL) +(defun unix-fast-select (num-descriptors + read-fds write-fds exception-fds + timeout-secs &optional (timeout-usecs 0)) + (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 - ;; be in a declaration inside the LET expansion, not in the - ;; macro compile-time code. - `(let ((timeout-secs ,timeout-secs)) - (with-alien ((tv (struct timeval))) - (when timeout-secs - (setf (slot tv 'tv-sec) timeout-secs) - (setf (slot tv 'tv-usec) ,timeout-usecs)) - (int-syscall ("select" int (* (struct fd-set)) (* (struct fd-set)) - (* (struct fd-set)) (* (struct timeval))) - ,num-descriptors ,read-fds ,write-fds ,exception-fds - (if timeout-secs (alien-sap (addr tv)) (int-sap 0)))))) + ;; (declare (optimize (speed 3) (safety 0) (inhibit-warnings 3))) + ;; here. Is that important for SBCL? If so, why? Profiling might tell us.. + (with-alien ((tv (struct timeval))) + (when timeout-secs + (setf (slot tv 'tv-sec) timeout-secs) + (setf (slot tv 'tv-usec) timeout-usecs)) + (int-syscall ("select" int (* (struct fd-set)) (* (struct fd-set)) + (* (struct fd-set)) (* (struct timeval))) + num-descriptors read-fds write-fds exception-fds + (if timeout-secs (alien-sap (addr tv)) (int-sap 0))))) ;;; UNIX-SELECT accepts sets of file descriptors and waits for an event ;;; to happen on one of them or to time out. @@ -532,93 +531,119 @@ ;;;; sys/stat.h -;;; FIXME: This is only used in this file, and needn't be in target Lisp -;;; runtime. It's also unclear why it needs to be a macro instead of a -;;; function. Perhaps it should become a FLET. -(defmacro extract-stat-results (buf) - `(values T ; result - (slot ,buf 'st-dev) - (slot ,buf 'st-ino) - (slot ,buf 'st-mode) - (slot ,buf 'st-nlink) - (slot ,buf 'st-uid) - (slot ,buf 'st-gid) - (slot ,buf 'st-rdev) - (slot ,buf 'st-size) - (slot ,buf 'st-atime) - (slot ,buf 'st-mtime) - (slot ,buf 'st-ctime) - (slot ,buf 'st-blksize) - (slot ,buf 'st-blocks))) - -;;; Retrieve information about the specified file returning them in -;;; the form of multiple values. See the UNIX Programmer's Manual for -;;; a description of the values returned. If the call fails, then NIL -;;; and an error number is returned instead. +;;; This is a structure defined in src/runtime/wrap.c, to look +;;; basically like "struct stat" according to stat(2). It may not +;;; actually correspond to the real in-memory stat structure that the +;;; syscall uses, and that's OK. Linux in particular is packed full of +;;; stat macros, and trying to keep Lisp code in correspondence with +;;; it is more pain than it's worth, so we just let our C runtime +;;; synthesize a nice consistent structure for us. +;;; +;;; Note that st-dev is a long, not a dev-t. This is because dev-t on +;;; linux 32 bit archs is a 64 bit quantity, but alien doesn's support +;;; those. We don't actually access that field anywhere, though, so +;;; until we can get 64 bit alien support it'll do. Also note that +;;; st_size is a long, not an off-t, because off-t is a 64-bit +;;; quantity on Alpha. And FIXME: "No one would want a file length +;;; longer than 32 bits anyway, right?":-| +(define-alien-type nil + (struct wrapped_stat + (st-dev unsigned-long) ; would be dev-t in a real stat + (st-ino ino-t) + (st-mode mode-t) + (st-nlink nlink-t) + (st-uid uid-t) + (st-gid gid-t) + (st-rdev unsigned-long) ; would be dev-t in a real stat + (st-size unsigned-long) ; would be off-t in a real stat + (st-blksize unsigned-long) + (st-blocks unsigned-long) + (st-atime time-t) + (st-mtime time-t) + (st-ctime time-t))) +;;; shared C-struct-to-multiple-VALUES conversion for the stat(2) +;;; family of Unix system calls +;;; +;;; FIXME: I think this should probably not be INLINE. However, when +;;; this was not inline, it seemed to cause memory corruption +;;; problems. My first guess is that it's a bug in the FFI code, where +;;; the WITH-ALIEN expansion doesn't deal well with being wrapped +;;; around a call to a function returning >10 values. But I didn't try +;;; to figure it out, just inlined it as a quick fix. Perhaps someone +;;; who's motivated to debug the FFI code can go over the DISASSEMBLE +;;; output in the not-inlined case and see whether there's a problem, +;;; and maybe even find a fix.. +(declaim (inline %extract-stat-results)) +(defun %extract-stat-results (wrapped-stat) + (declare (type (alien (* (struct wrapped_stat))) wrapped-stat)) + (values t + (slot wrapped-stat 'st-dev) + (slot wrapped-stat 'st-ino) + (slot wrapped-stat 'st-mode) + (slot wrapped-stat 'st-nlink) + (slot wrapped-stat 'st-uid) + (slot wrapped-stat 'st-gid) + (slot wrapped-stat 'st-rdev) + (slot wrapped-stat 'st-size) + (slot wrapped-stat 'st-atime) + (slot wrapped-stat 'st-mtime) + (slot wrapped-stat 'st-ctime) + (slot wrapped-stat 'st-blksize) + (slot wrapped-stat 'st-blocks))) + +;;; Unix system calls in the stat(2) family are handled by calls to +;;; C-level wrapper functions which copy all the raw "struct stat" +;;; slots into the system-independent wrapped_stat format. +;;; stat(2) <-> stat_wrapper() +;;; fstat(2) <-> fstat_wrapper() +;;; lstat(2) <-> lstat_wrapper() (defun unix-stat (name) (declare (type unix-pathname name)) - (when (string= name "") - (setf name ".")) - (with-alien ((buf (struct stat))) - (syscall ("stat_wrapper" c-string (* (struct stat))) - (extract-stat-results buf) + (with-alien ((buf (struct wrapped_stat))) + (syscall ("stat_wrapper" c-string (* (struct wrapped_stat))) + (%extract-stat-results (addr buf)) name (addr buf)))) - (defun unix-lstat (name) - #!+sb-doc - "Unix-lstat is identical to unix-stat, except if NAME is - a symlink, in which case it returns information about the - link itself rather than dereferencing it." (declare (type unix-pathname name)) - (with-alien ((buf (struct stat))) - (syscall ("lstat_wrapper" c-string (* (struct stat))) - (extract-stat-results buf) + (with-alien ((buf (struct wrapped_stat))) + (syscall ("lstat_wrapper" c-string (* (struct wrapped_stat))) + (%extract-stat-results (addr buf)) name (addr buf)))) - -;;; like UNIX-STAT except the file is specified by the file descriptor FD (defun unix-fstat (fd) (declare (type unix-fd fd)) - (with-alien ((buf (struct stat))) - (syscall ("fstat_wrapper" int (* (struct stat))) - (extract-stat-results buf) + (with-alien ((buf (struct wrapped_stat))) + (syscall ("fstat_wrapper" int (* (struct wrapped_stat))) + (%extract-stat-results (addr buf)) fd (addr buf)))) - - -;;; UNIX-MKDIR accepts a name and a mode and attempts to create the -;;; corresponding directory with mode mode. -(defun unix-mkdir (name mode) - (declare (type unix-pathname name) - (type unix-file-mode mode)) - (void-syscall ("mkdir" c-string int) name mode)) ;;;; time.h -;; the POSIX.4 structure for a time value. This is like a `struct -;; timeval' but has nanoseconds instead of microseconds. -(def-alien-type nil +;; the POSIX.4 structure for a time value. This is like a "struct +;; timeval" but has nanoseconds instead of microseconds. +(define-alien-type nil (struct timespec - (tv-sec long) ;Seconds - (tv-nsec long))) ;Nanoseconds + (tv-sec long) ; seconds + (tv-nsec long))) ; nanoseconds ;; used by other time functions -(def-alien-type nil +(define-alien-type nil (struct tm (tm-sec int) ; Seconds. [0-60] (1 leap second) (tm-min int) ; Minutes. [0-59] (tm-hour int) ; Hours. [0-23] - (tm-mday int) ; Day. [1-31] - (tm-mon int) ; Month. [0-11] - (tm-year int) ; Year - 1900. - (tm-wday int) ; Day of week. [0-6] - (tm-yday int) ; Days in year.[0-365] - (tm-isdst int) ; DST. [-1/0/1] - (tm-gmtoff long) ; Seconds east of UTC. - (tm-zone c-string))) ; Timezone abbreviation. - -(def-alien-routine get-timezone sb!c-call:void - (when sb!c-call:long :in) - (minutes-west sb!c-call:int :out) + (tm-mday int) ; Day. [1-31] + (tm-mon int) ; Month. [0-11] + (tm-year int) ; Year - 1900. + (tm-wday int) ; Day of week. [0-6] + (tm-yday int) ; Days in year. [0-365] + (tm-isdst int) ; DST. [-1/0/1] + (tm-gmtoff long) ; Seconds east of UTC. + (tm-zone c-string))) ; Timezone abbreviation. + +(define-alien-routine get-timezone sb!alien:void + (when sb!alien:long :in) + (minutes-west sb!alien:int :out) (daylight-savings-p sb!alien:boolean :out)) (defun unix-get-minutes-west (secs) @@ -636,7 +661,7 @@ ;;; Structure crudely representing a timezone. KLUDGE: This is ;;; obsolete and should never be used. -(def-alien-type nil +(define-alien-type nil (struct timezone (tz-minuteswest int) ; minutes west of Greenwich (tz-dsttime int))) ; type of dst correction @@ -691,96 +716,71 @@ ((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))) + (/noshow "entering UNIX-RESOLVE-LINKS") + (loop with previous-pathnames = nil do + (/noshow pathname previous-pathnames) + (let ((link (unix-readlink pathname))) + (/noshow 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))) + (/noshow 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 #\.) @@ -790,12 +790,12 @@ ((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 .. @@ -823,7 +823,7 @@ (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)) @@ -855,6 +855,17 @@ (t (subseq dst 0 dst-len))))) +;;;; A magic constant for wait3(). +;;;; +;;;; FIXME: This used to be defined in run-program.lisp as +;;;; (defconstant wait-wstopped #-svr4 #o177 #+svr4 wait-wuntraced) +;;;; According to some of the man pages, the #o177 is part of the API +;;;; for wait3(); that said, under SunOS there is a WSTOPPED thing in +;;;; the headers that may or may not be the same thing. To be +;;;; investigated. -- CSR, 2002-03-25 +(defconstant wstopped #o177) + + ;;;; stuff not yet found in the header files ;;;; ;;;; Abandon all hope who enters here...