diff options
| -rw-r--r-- | share/txr/stdlib/getput.tl | 33 | ||||
| -rw-r--r-- | txr.1 | 24 |
2 files changed, 42 insertions, 15 deletions
diff --git a/share/txr/stdlib/getput.tl b/share/txr/stdlib/getput.tl index 61523d8e..a50ee109 100644 --- a/share/txr/stdlib/getput.tl +++ b/share/txr/stdlib/getput.tl @@ -24,16 +24,25 @@ ;; OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE ;; OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. -(defun sys:get-buf-common (s) - (let ((b (make-buf 4096)) +(defun sys:get-buf-common (s bytes seek) + (let ((b (make-buf 0 0 (min bytes 4096))) (o 0)) - (while t - (let ((p (fill-buf b o s))) - (when (< p (len b)) - (buf-set-length b (if (plusp p) p o)) + (when (plusp seek) + (unless (ignerr (seek-stream s seek :from-current)) + (let ((b (make-buf (min seek 4096))) + (c 0)) + (while (< c seek) + (let ((p (fill-buf b 0 s))) + (if (zerop p) + (return)) + (inc c p)))))) + (while (or (null bytes) (< (len b) bytes)) + (let ((p (fill-buf-adjust b o s))) + (when (= p o) (return)) - (buf-set-length b (+ p (len b))) - (set o p))) + (set o p) + (when (eql p (buf-alloc-size b)) + (buf-set-length b (min (+ p p) bytes))))) b)) (defun file-get (name) @@ -71,9 +80,9 @@ (with-stream (s (open-file name "a")) (put-lines lines s))) -(defun file-get-buf (name) +(defun file-get-buf (name : bytes (seek 0)) (with-stream (s (open-file name "rb")) - (sys:get-buf-common s))) + (sys:get-buf-common s bytes seek))) (defun file-put-buf (name buf) (with-stream (s (open-file name "wb")) @@ -106,9 +115,9 @@ (with-stream (s (open-command cmd "w")) (put-lines lines s))) -(defun command-get-buf (cmd) +(defun command-get-buf (cmd : bytes (skip 0)) (with-stream (s (open-command cmd "rb")) - (sys:get-buf-common s))) + (sys:get-buf-common s bytes skip))) (defun command-put-buf (cmd buf) (with-stream (s (open-command cmd "wb")) @@ -24947,15 +24947,15 @@ adjusts the length of the buffer to match the position that is returned. .coNP Functions @ file-get-buf and @ command-get-buf .synb -.mets (file-get-buf << name ) -.mets (command-get-buf << cmd ) +.mets (file-get-buf < name >> [ max-bytes <> [ skip-bytes ]]) +.mets (command-get-buf < cmd >> [ max-bytes <> [ skip-bytes ]]) .syne .desc The .code file-get-buf function opens a binary stream over the file indicated by the string argument .meta name -for reading. The entire file is read and its contents are returned as a +for reading. By default, the entire file is read and its contents are returned as a buffer object. The buffer's length corresponds to the number of bytes read from the file. @@ -24969,6 +24969,24 @@ as if by the function. It read bytes from the pipe until the indication that no more input is available. The bytes are returned aggregated into a buffer object. +If the +.meta max-bytes +parameter is given an argument, it must be a non-negative integer. +That value specifies a limit on the number of bytes to read. A buffer +no longer than +.meta max-bytes +shall be returned. + +If the +.meta skip-bytes +parameter is given an argument, it must be a non-negative integer. +That value specifies how many initial bytes of the input should be +discarded before accumulation of the buffer begins. +If possible, the semantics of this parameter is achieved by performing a +.code seek-stream +operation, falling back on reading and discarding bytes if the +stream doesn't support seeking. + .coNP Functions @, file-put-buf @ file-append-buf and @ command-put-buf .synb .mets (file-put-buf < name << buf ) |