@c -*-texinfo-*-
@c This is part of the GNU Guile Reference Manual.
@c Copyright (C) 1996, 1997, 2000, 2001, 2002, 2003, 2004, 2006, 2007,
-@c 2008, 2009, 2010, 2011, 2012 Free Software Foundation, Inc.
+@c 2008, 2009, 2010, 2011, 2012, 2013, 2014 Free Software Foundation, Inc.
@c See the file guile.texi for copying conditions.
@node POSIX
block buffered, using a newly allocated buffer of @var{size} bytes.
If @var{size} is omitted, a default size will be used.
@end defvar
+
+Only certain types of ports are supported, most importantly
+file ports.
@end deffn
@deffn {Scheme Procedure} fcntl port/fd cmd [value]
The return value is unspecified.
@end deffn
+@deffn {Scheme Procedure} sendfile out in count [offset]
+@deffnx {C Function} scm_sendfile (out, in, count, offset)
+Send @var{count} bytes from @var{in} to @var{out}, both of which
+must be either open file ports or file descriptors. When
+@var{offset} is omitted, start reading from @var{in}'s current
+position; otherwise, start reading at @var{offset}. Return
+the number of bytes actually sent.
+
+When @var{in} is a port, it is often preferable to specify @var{offset},
+because @var{in}'s offset as a port may be different from the offset of
+its underlying file descriptor.
+
+On systems that support it, such as GNU/Linux, this procedure uses the
+@code{sendfile} libc function, which usually corresponds to a system
+call. This is faster than doing a series of @code{read} and
+@code{write} system calls. A typical application is to send a file over
+a socket.
+
+In some cases, the @code{sendfile} libc function may return
+@code{EINVAL} or @code{ENOSYS}. In that case, Guile's @code{sendfile}
+procedure automatically falls back to doing a series of @code{read} and
+@code{write} calls.
+
+In other cases, the libc function may send fewer bytes than
+@var{count}---for instance because @var{out} is a slow or limited
+device, such as a pipe. When that happens, Guile's @code{sendfile}
+automatically retries until exactly @var{count} bytes were sent or an
+error occurs.
+@end deffn
+
@findex rename
@deffn {Scheme Procedure} rename-file oldname newname
@deffnx {C Function} scm_rename (oldname, newname)
@end deffn
@deffn {Scheme Procedure} tmpfile
-@deffnx {C Function} scm_tmpfile
+@deffnx {C Function} scm_tmpfile ()
Return an input/output port to a unique temporary file
named using the path prefix @code{P_tmpdir} defined in
@file{stdio.h}.
not.
@end deffn
+@cindex file name separator
+@cindex absolute file name
+
+Many operating systems, such as GNU, use @code{/} (forward slash) to
+separate the components of a file name; any file name starting with
+@code{/} is considered an @dfn{absolute file name}. These conventions
+are specified by the POSIX Base Definitions, which refer to conforming
+file names as ``pathnames''. Some operating systems use a different
+convention; in particular, Windows uses @code{\} (backslash) as the file
+name separator, and also has the notion of @dfn{volume names} like
+@code{C:\} for absolute file names. The following procedures and
+variables provide support for portable file name manipulations.
+
+@deffn {Scheme Procedure} system-file-name-convention
+Return either @code{posix} or @code{windows}, depending on
+what kind of system this Guile is running on.
+@end deffn
+
+@deffn {Scheme Procedure} file-name-separator? c
+Return true if character @var{c} is a file name separator on the host
+platform.
+@end deffn
+
+@deffn {Scheme Procedure} absolute-file-name? file-name
+Return true if @var{file-name} denotes an absolute file name on the host
+platform.
+@end deffn
+
+@defvr {Scheme Variable} file-name-separator-string
+The preferred file name separator.
+
+Note that on MinGW builds for Windows, both @code{/} and @code{\} are
+valid separators. Thus, programs should not assume that
+@code{file-name-separator-string} is the @emph{only} file name
+separator---e.g., when extracting the components of a file name.
+@end defvr
+
@node User Information
@subsection User Information
Example: (system* "echo" "foo" "bar")
@end deffn
+@deffn {Scheme Procedure} quit [status]
+@deffnx {Scheme Procedure} exit [status]
+Terminate the current process with proper unwinding of the Scheme stack.
+The exit status zero if @var{status} is not supplied. If @var{status}
+is supplied, and it is an integer, that integer is used as the exit
+status. If @var{status} is @code{#t} or @code{#f}, the exit status is 0
+or 1, respectively.
+
+The procedure @code{exit} is an alias of @code{quit}. They have the
+same functionality.
+@end deffn
+
@deffn {Scheme Procedure} primitive-exit [status]
@deffnx {Scheme Procedure} primitive-_exit [status]
@deffnx {C Function} scm_primitive_exit (status)
In the child the return value is 0. In the parent the return value is
the integer process ID of the child.
+Note that it is unsafe to fork a process that has multiple threads
+running, as only the thread that calls @code{primitive-fork} will
+persist in the child. Any resources that other threads held, such as
+locked mutexes or open file descriptors, are lost. Indeed, @acronym{POSIX}
+specifies that only async-signal-safe procedures are safe to call after
+a multithreaded fork, which is a very limited set. Guile issues a
+warning if it detects a fork from a multi-threaded program.
+
+If you are going to @code{exec} soon after forking, the procedures in
+@code{(ice-9 popen)} may be useful to you, as they fork and exec within
+an async-signal-safe function carefully written to ensure robust program
+behavior, even in the presence of threads. @xref{Pipes}, for more.
+
This procedure has been renamed from @code{fork} to avoid a naming conflict
with the scsh fork.
@end deffn
The following procedures are similar to the @code{popen} and
@code{pclose} system routines. The code is in a separate ``popen''
-module:
+module@footnote{This module is only available on systems where the
+@code{fork} feature is provided (@pxref{Common Feature Symbols}).}:
@lisp
(use-modules (ice-9 popen))
@var{hint_socktype} was not recognized.
@item EAI_SYSTEM
-A system error occurred; the error code can be found in
-@code{errno}.
+A system error occurred. In C, the error code can be found in
+@code{errno}; this value is not accessible from Scheme, but in
+practice it provides little information about the actual error
+cause.
+@c See <http://bugs.gnu.org/13958>.
@end table
Users are encouraged to read the
@deffn {Scheme Procedure} make-socket-address AF_INET ipv4addr port
@deffnx {Scheme Procedure} make-socket-address AF_INET6 ipv6addr port [flowinfo [scopeid]]
@deffnx {Scheme Procedure} make-socket-address AF_UNIX path
-@deffnx {C Function} scm_make_socket_address family address arglist
+@deffnx {C Function} scm_make_socket_address (family, address, arglist)
Return a new socket address object. The first argument is the address
family, one of the @code{AF} constants, then the arguments vary
according to the family.
@defvarx SO_OOBINLINE
@defvarx SO_NO_CHECK
@defvarx SO_PRIORITY
+@defvarx SO_REUSEPORT
The @var{value} taken or returned is an integer.
@end defvar
any unflushed buffered port data is ignored.
@end deffn
-The following functions can be used to convert short and long integers
-between ``host'' and ``network'' order. Although the procedures above do
-this automatically for addresses, the conversion will still need to
-be done when sending or receiving encoded integer data from the network.
-
-@deffn {Scheme Procedure} htons value
-@deffnx {C Function} scm_htons (value)
-Convert a 16 bit quantity from host to network byte ordering.
-@var{value} is packed into 2 bytes, which are then converted
-and returned as a new integer.
-@end deffn
-
-@deffn {Scheme Procedure} ntohs value
-@deffnx {C Function} scm_ntohs (value)
-Convert a 16 bit quantity from network to host byte ordering.
-@var{value} is packed into 2 bytes, which are then converted
-and returned as a new integer.
-@end deffn
-
-@deffn {Scheme Procedure} htonl value
-@deffnx {C Function} scm_htonl (value)
-Convert a 32 bit quantity from host to network byte ordering.
-@var{value} is packed into 4 bytes, which are then converted
-and returned as a new integer.
-@end deffn
-
-@deffn {Scheme Procedure} ntohl value
-@deffnx {C Function} scm_ntohl (value)
-Convert a 32 bit quantity from network to host byte ordering.
-@var{value} is packed into 4 bytes, which are then converted
-and returned as a new integer.
-@end deffn
-
-These procedures are inconvenient to use at present, but consider:
-
-@example
-(define write-network-long
- (lambda (value port)
- (let ((v (make-uniform-vector 1 1 0)))
- (uniform-vector-set! v 0 (htonl value))
- (uniform-vector-write v port))))
-
-(define read-network-long
- (lambda (port)
- (let ((v (make-uniform-vector 1 1 0)))
- (uniform-vector-read! v port)
- (ntohl (uniform-vector-ref v 0)))))
-@end example
-
@node Internet Socket Examples
@subsubsection Network Socket Examples
HCoop / bpt / guile.git / blobdiff