64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
|
the data.
An encoding error is reported by the POSIX error code \fBEILSEQ\fR.
.PP
In blocking mode, the error is directly thrown, even, if there is a
leading decodable data portion.
The file pointer is advanced just before the encoding error.
An eventual well decoded data chunk before the encoding error is returned
in the error option dictionary key \fB-result read\fR.
The value of the key contains the empty string, if the error arises at the
first data position.
.PP
In non blocking mode, first, any data without encoding error is returned
(without error state).
In the next call, no data is returned and the \fBEILSEQ\fR error state is set.
The key \fB-result read\fR is not present.
.PP
Here is an example with an encoding error in UTF-8 encoding, which is then
introspected by a switch to the binary encoding. The test file contains a not
continued multi-byte sequence at position 1 (\fBA \\xC3 B\fR):
.PP
File creation for examples
.
|
|
|
|
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
|
the data.
An encoding error is reported by the POSIX error code \fBEILSEQ\fR.
.PP
In blocking mode, the error is directly thrown, even, if there is a
leading decodable data portion.
The file pointer is advanced just before the encoding error.
An eventual well decoded data chunk before the encoding error is returned
in the error option dictionary key \fB\-result read\fR.
The value of the key contains the empty string, if the error arises at the
first data position.
.PP
In non blocking mode, first, any data without encoding error is returned
(without error state).
In the next call, no data is returned and the \fBEILSEQ\fR error state is set.
The key \fB\-result read\fR is not present.
.PP
Here is an example with an encoding error in UTF-8 encoding, which is then
introspected by a switch to the binary encoding. The test file contains a not
continued multi-byte sequence at position 1 (\fBA \\xC3 B\fR):
.PP
File creation for examples
.
|
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
|
1
% fconfigure $f -encoding binary -profile strict
% read $f
ÃB
% close $f
.CE
The already decoded data "A" is returned in the error options dictionary key
\fB-result read\fR.
The file position is advanced on the encoding error position 1.
The data at the error position is thus recovered by the next \fBread\fR command.
.PP
Non blocking example
.
.CS
% set f [open test_A_195_B.txt r]
|
|
|
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
|
1
% fconfigure $f -encoding binary -profile strict
% read $f
ÃB
% close $f
.CE
The already decoded data "A" is returned in the error options dictionary key
\fB\-result read\fR.
The file position is advanced on the encoding error position 1.
The data at the error position is thus recovered by the next \fBread\fR command.
.PP
Non blocking example
.
.CS
% set f [open test_A_195_B.txt r]
|
158
159
160
161
162
163
164
165
166
167
168
|
set data [\fBread\fR $fl]
close $fl
set lines [split $data \en]
.CE
.SH "SEE ALSO"
file(n), eof(n), fblocked(n), fconfigure(n), Tcl_StandardChannels(3)
.SH KEYWORDS
blocking, channel, end of line, end of file, nonblocking, read, translation, encoding
'\"Local Variables:
'\"mode: nroff
'\"End:
|
|
>
|
158
159
160
161
162
163
164
165
166
167
168
169
|
set data [\fBread\fR $fl]
close $fl
set lines [split $data \en]
.CE
.SH "SEE ALSO"
file(n), eof(n), fblocked(n), fconfigure(n), Tcl_StandardChannels(3)
.SH KEYWORDS
blocking, channel, end of line, end of file, nonblocking, read, translation,
encoding
'\"Local Variables:
'\"mode: nroff
'\"End:
|