diff options
Diffstat (limited to 'doc/OpenFileChnl.3')
| -rw-r--r-- | doc/OpenFileChnl.3 | 94 |
1 files changed, 32 insertions, 62 deletions
diff --git a/doc/OpenFileChnl.3 b/doc/OpenFileChnl.3 index 10c92f6..582ff4b 100644 --- a/doc/OpenFileChnl.3 +++ b/doc/OpenFileChnl.3 @@ -98,10 +98,8 @@ Tcl_WideInt Tcl_WideInt \fBTcl_Tell\fR(\fIchannel\fR) .sp -.VS 8.5 int \fBTcl_TruncateChannel\fR(\fIchannel, length\fR) -.VE 8.5 .sp int \fBTcl_GetChannelOption\fR(\fIinterp, channel, optionName, optionValue\fR) @@ -117,7 +115,7 @@ Used for error reporting and to look up a channel registered in it. The name of a local or network file. .AP "const char" *mode in Specifies how the file is to be accessed. May have any of the values -allowed for the \fImode\fR argument to the Tcl \fBopen\fR command. +allowed for the \fImode\fR argument to the Tcl \fBopen\fR command. .AP int permissions in POSIX-style permission flags such as 0644. If a new file is created, these permissions will be set on the created file. @@ -143,7 +141,7 @@ file descriptor, for Windows it is a HANDLE. OR-ed combination of \fBTCL_READABLE\fR and \fBTCL_WRITABLE\fR to indicate what operations are valid on \fIhandle\fR. .AP "const char" *channelName in -The name of the channel. +The name of the channel. .AP int *modePtr out Points at an integer variable that will receive an OR-ed combination of \fBTCL_READABLE\fR and \fBTCL_WRITABLE\fR denoting whether the channel is @@ -154,24 +152,24 @@ The pattern to match on, passed to Tcl_StringMatch, or NULL. A Tcl channel for input or output. Must have been the return value from a procedure such as \fBTcl_OpenFileChannel\fR. .AP Tcl_Obj *readObjPtr in/out -A pointer to a Tcl Object in which to store the characters read from the +A pointer to a Tcl value in which to store the characters read from the channel. .AP int charsToRead in -The number of characters to read from the channel. If the channel's encoding -is \fBbinary\fR, this is equivalent to the number of bytes to read from the +The number of characters to read from the channel. If the channel's encoding +is \fBbinary\fR, this is equivalent to the number of bytes to read from the channel. .AP int appendFlag in -If non-zero, data read from the channel will be appended to the object. -Otherwise, the data will replace the existing contents of the object. +If non-zero, data read from the channel will be appended to the value. +Otherwise, the data will replace the existing contents of the value. .AP char *readBuf out A buffer in which to store the bytes read from the channel. .AP int bytesToRead in The number of bytes to read from the channel. The buffer \fIreadBuf\fR must be large enough to hold this many bytes. .AP Tcl_Obj *lineObjPtr in/out -A pointer to a Tcl object in which to store the line read from the +A pointer to a Tcl value in which to store the line read from the channel. The line read will be appended to the current value of the -object. +value. .AP Tcl_DString *lineRead in/out A pointer to a Tcl dynamic string in which to store the line read from the channel. Must have been initialized by the caller. The line read will be @@ -184,7 +182,7 @@ Length of the input Flag indicating whether the input should be added to the end or beginning of the channel buffer. .AP Tcl_Obj *writeObjPtr in -A pointer to a Tcl Object whose contents will be output to the channel. +A pointer to a Tcl value whose contents will be output to the channel. .AP "const char" *charBuf in A buffer containing the characters to output to the channel. .AP "const char" *byteBuf in @@ -211,7 +209,6 @@ values. Must have been initialized by the caller. .AP "const char" *newValue in New value for the option given by \fIoptionName\fR. .BE - .SH DESCRIPTION .PP The Tcl channel mechanism provides a device-independent and @@ -229,7 +226,6 @@ The procedures described in this manual entry comprise the C APIs of the generic layer of the channel architecture. For a description of the channel driver architecture and how to implement channel drivers for new types of channels, see the manual entry for \fBTcl_CreateChannel\fR. - .SH TCL_OPENFILECHANNEL .PP \fBTcl_OpenFileChannel\fR opens a file specified by \fIfileName\fR and @@ -242,16 +238,15 @@ If an error occurs while opening the channel, \fBTcl_OpenFileChannel\fR returns NULL and records a POSIX error code that can be retrieved with \fBTcl_GetErrno\fR. In addition, if \fIinterp\fR is non-NULL, \fBTcl_OpenFileChannel\fR -leaves an error message in \fIinterp\fR's result after any error. -As of Tcl 8.4, the object-based API \fBTcl_FSOpenFileChannel\fR should +leaves an error message in \fIinterp\fR's result after any error. +As of Tcl 8.4, the value-based API \fBTcl_FSOpenFileChannel\fR should be used in preference to \fBTcl_OpenFileChannel\fR wherever possible. .PP The newly created channel is not registered in the supplied interpreter; to register it, use \fBTcl_RegisterChannel\fR, described below. -If one of the standard channels, \fBstdin, stdout\fR or \fBstderr\fR was +If one of the standard channels, \fBstdin\fR, \fBstdout\fR or \fBstderr\fR was previously closed, the act of creating the new channel also assigns it as a replacement for the standard channel. - .SH TCL_OPENCOMMANDCHANNEL .PP \fBTcl_OpenCommandChannel\fR provides a C-level interface to the @@ -286,20 +281,18 @@ the interpreter's result if \fIinterp\fR is not NULL. .PP The newly created channel is not registered in the supplied interpreter; to register it, use \fBTcl_RegisterChannel\fR, described below. -If one of the standard channels, \fBstdin, stdout\fR or \fBstderr\fR was +If one of the standard channels, \fBstdin\fR, \fBstdout\fR or \fBstderr\fR was previously closed, the act of creating the new channel also assigns it as a replacement for the standard channel. - .SH TCL_MAKEFILECHANNEL .PP \fBTcl_MakeFileChannel\fR makes a \fBTcl_Channel\fR from an existing, platform-specific, file handle. The newly created channel is not registered in the supplied interpreter; to register it, use \fBTcl_RegisterChannel\fR, described below. -If one of the standard channels, \fBstdin, stdout\fR or \fBstderr\fR was +If one of the standard channels, \fBstdin\fR, \fBstdout\fR or \fBstderr\fR was previously closed, the act of creating the new channel also assigns it as a replacement for the standard channel. - .SH TCL_GETCHANNEL .PP \fBTcl_GetChannel\fR returns a channel given the \fIchannelName\fR used to @@ -312,12 +305,11 @@ open for reading and writing. .PP \fBTcl_GetChannelNames\fR and \fBTcl_GetChannelNamesEx\fR write the names of the registered channels to the interpreter's result as a -list object. \fBTcl_GetChannelNamesEx\fR will filter these names +list value. \fBTcl_GetChannelNamesEx\fR will filter these names according to the \fIpattern\fR. If \fIpattern\fR is NULL, then it will not do any filtering. The return value is \fBTCL_OK\fR if no errors occurred writing to the result, otherwise it is \fBTCL_ERROR\fR, and the error message is left in the interpreter's result. - .SH TCL_REGISTERCHANNEL .PP \fBTcl_RegisterChannel\fR adds a channel to the set of channels accessible @@ -340,9 +332,8 @@ This procedure interacts with the code managing the standard channels. If no standard channels were initialized before the first call to \fBTcl_RegisterChannel\fR, they will get initialized by that call. See \fBTcl_StandardChannels\fR for a general treatise about -standard channels and the behaviour of the Tcl library with regard to +standard channels and the behavior of the Tcl library with regard to them. - .SH TCL_UNREGISTERCHANNEL .PP \fBTcl_UnregisterChannel\fR removes a channel from the set of channels @@ -357,31 +348,28 @@ that it no longer holds a reference to that channel. If this is the last reference to the channel, it will now be closed. \fBTcl_UnregisterChannel\fR is very similar to \fBTcl_DetachChannel\fR except that it will also close the channel if no further references to it exist. - .SH TCL_DETACHCHANNEL .PP \fBTcl_DetachChannel\fR removes a channel from the set of channels accessible in \fIinterp\fR. After this call, Tcl programs will no longer be able to use the channel's name to refer to the channel in that interpreter. Beyond that, this command has no further effect. It cannot be used on -the standard channels (stdout, stderr, stdin), and will return +the standard channels (\fBstdout\fR, \fBstderr\fR, \fBstdin\fR), and will return \fBTCL_ERROR\fR if passed one of those channels. .PP Code not associated with a Tcl interpreter can call \fBTcl_DetachChannel\fR with \fIinterp\fR as NULL, to indicate to Tcl that it no longer holds a reference to that channel. If this is the last -reference to the channel, unlike \fBTcl_UnregisterChannel\fR, +reference to the channel, unlike \fBTcl_UnregisterChannel\fR, it will not be closed. - .SH TCL_ISSTANDARDCHANNEL .PP \fBTcl_IsStandardChannel\fR tests whether a channel is one of the -three standard channels, stdin, stdout or stderr. If so, it returns -1, otherwise 0. +three standard channels, \fBstdin\fR, \fBstdout\fR or \fBstderr\fR. +If so, it returns 1, otherwise 0. .PP -No attempt is made to check whether the given channel or the standard +No attempt is made to check whether the given channel or the standard channels are initialized or otherwise valid. - .SH TCL_CLOSE .PP \fBTcl_Close\fR destroys the channel \fIchannel\fR, which must denote a @@ -411,11 +399,10 @@ been given as the \fBchan\fR argument in a call to \fBTcl_UnregisterChannel\fR, which will internally call \fBTcl_Close\fR when all calls to \fBTcl_RegisterChannel\fR have been matched by corresponding calls to \fBTcl_UnregisterChannel\fR. - .SH "TCL_READCHARS AND TCL_READ" .PP \fBTcl_ReadChars\fR consumes bytes from \fIchannel\fR, converting the bytes -to UTF-8 based on the channel's encoding and storing the produced data in +to UTF-8 based on the channel's encoding and storing the produced data in \fIreadObjPtr\fR's string representation. The return value of \fBTcl_ReadChars\fR is the number of characters, up to \fIcharsToRead\fR, that were stored in \fIreadObjPtr\fR. If an error occurs while reading, the @@ -448,7 +435,7 @@ platform-specific modes are described in the manual entry for the Tcl As a performance optimization, when reading from a channel with the encoding \fBbinary\fR, the bytes are not converted to UTF-8 as they are read. Instead, they are stored in \fIreadObjPtr\fR's internal representation as a -byte-array object. The string representation of this object will only be +byte-array value. The string representation of this value will only be constructed if it is needed (e.g., because of a call to \fBTcl_GetStringFromObj\fR). In this way, byte-oriented data can be read from a channel, manipulated by calling \fBTcl_GetByteArrayFromObj\fR and @@ -463,7 +450,7 @@ extensions. It consumes bytes from \fIchannel\fR and stores them in of \fBTcl_Read\fR is the number of bytes, up to \fIbytesToRead\fR, written in \fIreadBuf\fR. The buffer produced by \fBTcl_Read\fR is not null-terminated. Its contents are valid from the zeroth position up to and excluding the -position indicated by the return value. +position indicated by the return value. .PP \fBTcl_ReadRaw\fR is the same as \fBTcl_Read\fR but does not compensate for stacking. While \fBTcl_Read\fR (and the other functions @@ -472,7 +459,6 @@ stack the supplied channel is part of, \fBTcl_ReadRaw\fR does not. Thus this function is \fBonly\fR usable for transformational channel drivers, i.e. drivers used in the middle of a stack of channels, to move data from the channel below into the transformation. - .SH "TCL_GETSOBJ AND TCL_GETS" .PP \fBTcl_GetsObj\fR consumes bytes from \fIchannel\fR, converting the bytes to @@ -498,8 +484,7 @@ of input unavailability. .PP \fBTcl_Gets\fR is the same as \fBTcl_GetsObj\fR except the resulting characters are appended to the dynamic string given by -\fIlineRead\fR rather than a Tcl object. - +\fIlineRead\fR rather than a Tcl value. .SH "TCL_UNGETS" .PP \fBTcl_Ungets\fR is used to add data to the input queue of a channel, @@ -512,7 +497,6 @@ head of the queue. If \fIchannel\fR has a EOF set, no data will be added to the input queue. \fBTcl_Ungets\fR returns \fIinputLen\fR or \-1 if an error occurs. - .SH "TCL_WRITECHARS, TCL_WRITEOBJ, AND TCL_WRITE" .PP \fBTcl_WriteChars\fR accepts \fIbytesToWrite\fR bytes of character data at @@ -523,7 +507,7 @@ to be null-terminated and it outputs everything up to the null. .PP Data queued for output may not appear on the output device immediately, due to internal buffering. If the data should appear immediately, call -\fBTcl_Flush\fR after the call to \fBTcl_WriteChars\fR, or set the +\fBTcl_Flush\fR after the call to \fBTcl_WriteChars\fR, or set the \fB\-buffering\fR option on the channel to \fBnone\fR. If you wish the data to appear as soon as a complete line is accepted for output, set the \fB\-buffering\fR option on the channel to \fBline\fR mode. @@ -539,14 +523,14 @@ end-of-line sequences according to the \fB\-translation\fR option for the channel. This is done even if the channel has no encoding. .PP \fBTcl_WriteObj\fR is similar to \fBTcl_WriteChars\fR except it -accepts a Tcl object whose contents will be output to the channel. The +accepts a Tcl value whose contents will be output to the channel. The UTF-8 characters in \fIwriteObjPtr\fR's string representation are converted -to the channel's encoding and queued for output to \fIchannel\fR. +to the channel's encoding and queued for output to \fIchannel\fR. As a performance optimization, when writing to a channel with the encoding \fBbinary\fR, UTF-8 characters are not converted as they are written. Instead, the bytes in \fIwriteObjPtr\fR's internal representation as a -byte-array object are written to the channel. The byte-array representation -of the object will be constructed if it is needed. In this way, +byte-array value are written to the channel. The byte-array representation +of the value will be constructed if it is needed. In this way, byte-oriented data can be read from a channel, manipulated by calling \fBTcl_GetByteArrayFromObj\fR and related functions, and then written to a channel without the expense of ever converting to or from UTF-8. @@ -567,7 +551,6 @@ not. Thus this function is \fBonly\fR usable for transformational channel drivers, i.e. drivers used in the middle of a stack of channels, to move data from the transformation into the channel below it. - .SH TCL_FLUSH .PP \fBTcl_Flush\fR causes all of the buffered output data for \fIchannel\fR @@ -581,7 +564,6 @@ eventually, as fast as the channel is able to absorb it. The return value is normally \fBTCL_OK\fR. If an error occurs, \fBTcl_Flush\fR returns \fBTCL_ERROR\fR and records a POSIX error code that can be retrieved with \fBTcl_GetErrno\fR. - .SH TCL_SEEK .PP \fBTcl_Seek\fR moves the access point in \fIchannel\fR where subsequent @@ -592,20 +574,15 @@ buffered input is discarded, prior to the seek operation. If an error occurs, \fBTcl_Seek\fR returns \-1 and records a POSIX error code that can be retrieved with \fBTcl_GetErrno\fR. After an error, the access point may or may not have been moved. - .SH TCL_TELL .PP \fBTcl_Tell\fR returns the current access point for a channel. The returned value is \-1 if the channel does not support seeking. - .SH TCL_TRUNCATECHANNEL .PP -.VS 8.5 \fBTcl_TruncateChannel\fR truncates the file underlying \fIchannel\fR to a given \fIlength\fR of bytes. It returns \fBTCL_OK\fR if the operation succeeded, and \fBTCL_ERROR\fR otherwise. -.VE 8.5 - .SH TCL_GETCHANNELOPTION .PP \fBTcl_GetChannelOption\fR retrieves, in \fIoptionValue\fR, the value of one of @@ -627,7 +604,6 @@ for the Tcl \fBsocket\fR command. The procedure normally returns \fBTCL_OK\fR. If an error occurs, it returns \fBTCL_ERROR\fR and calls \fBTcl_SetErrno\fR to store an appropriate POSIX error code. - .SH TCL_SETCHANNELOPTION .PP \fBTcl_SetChannelOption\fR sets a new value \fInewValue\fR @@ -635,30 +611,26 @@ for an option \fIoptionName\fR on \fIchannel\fR. The procedure normally returns \fBTCL_OK\fR. If an error occurs, it returns \fBTCL_ERROR\fR; in addition, if \fIinterp\fR is non-NULL, \fBTcl_SetChannelOption\fR leaves an error message in the interpreter's result. - .SH TCL_EOF .PP \fBTcl_Eof\fR returns a nonzero value if \fIchannel\fR encountered an end of file during the last input operation. - .SH TCL_INPUTBLOCKED .PP \fBTcl_InputBlocked\fR returns a nonzero value if \fIchannel\fR is in nonblocking mode and the last input operation returned less data than requested because there was insufficient data available. The call always returns zero if the channel is in blocking mode. - .SH TCL_INPUTBUFFERED .PP \fBTcl_InputBuffered\fR returns the number of bytes of input currently buffered in the internal buffers for a channel. If the channel is not open for reading, this function always returns zero. - .SH TCL_OUTPUTBUFFERED +.PP \fBTcl_OutputBuffered\fR returns the number of bytes of output currently buffered in the internal buffers for a channel. If the channel is not open for writing, this function always returns zero. - .SH "PLATFORM ISSUES" .PP The handles returned from \fBTcl_GetChannelHandle\fR depend on the @@ -669,10 +641,8 @@ the channel was created with \fBTcl_OpenFileChannel\fR, \fBTcl_OpenCommandChannel\fR, or \fBTcl_MakeFileChannel\fR. Other channel types may return a different type of handle on Windows platforms. - .SH "SEE ALSO" DString(3), fconfigure(n), filename(n), fopen(3), Tcl_CreateChannel(3) - .SH KEYWORDS access point, blocking, buffered I/O, channel, channel driver, end of file, flush, input, nonblocking, output, read, seek, write |