I got the following exception on a line of code that is basically "line = readln()" and need help in understanding what the exception is saying. (I am playing around with stdio prior to this using unix ioctls and maybe I am messing something up in the process resulting in this, but understanding the exception will give me a clue as to what I am doing wrong -- a basic D progam with readln() doesn't have the same issue). This is on linux with DMD version 2.07.

std.stdio.StdioException@std/stdio.d(3969)
----------------
??:? void std.stdio.StdioException.opCall() [0x4c8891]
??:? ulong std.stdio.readlnImpl(shared(core.stdc.stdio._IO_FILE)*, ref char[], dchar, std.stdio.File.Orientation) [0x4c89e5]
/usr/include/dmd/phobos/std/stdio.d:1547 ulong std.stdio.File.readln!(char).readln(ref char[], dchar) [0x4acd95]
/usr/include/dmd/phobos/std/stdio.d:1408 immutable(char)[] std.stdio.File.readln!(immutable(char)[]).readln(dchar) [0x4acca2]
/usr/include/dmd/phobos/std/stdio.d:3377 immutable(char)[] std.stdio.readln!(immutable(char)[]).readln(dchar) [0x4acc2f]
telnetc.d:1572 void telnetc.handleEscapeMode(telnetc.TelnetInfo, ubyte) [0x4a6638]
telnetc.d:1591 void telnetc.handleKey(telnetc.TelnetInfo, ubyte) [0x4a6707]
telnetc.d:1603 void telnetc.handleKeyPress(telnetc.TelnetInfo, ubyte[]) [0x4a6788]
telnetc.d:1740 bool telnetc.readSocket!(void function(telnetc.TelnetInfo, ubyte[])*, telnetc.TelnetInfo).readSocket(immutable(char)[], std.socket.Socket, void function(telnetc.TelnetInfo, ubyte[])*, telnetc.TelnetInfo) [0x4adb18]
telnetc.d:1802 void telnetc.receiveAndProcessData(telnetc.TelnetInfo) [0x4a6f00]
telnetc.d:2165 _Dmain [0x4a7831]
??:? _D2rt6dmain211_d_run_mainUiPPaPUAAaZiZ6runAllMFZ9__lambda1MFZv [0x4b9742]
??:? void rt.dmain2._d_run_main(int, char**, extern (C) int function(char[][])*).tryExec(scope void delegate()) [0x4b9680]
??:? void rt.dmain2._d_run_main(int, char**, extern (C) int function(char[][])*).runAll() [0x4b96fe]
??:? void rt.dmain2._d_run_main(int, char**, extern (C) int function(char[][])*).tryExec(scope void delegate()) [0x4b9680]
??:? _d_run_main [0x4b95dd]
??:? main [0x4b3827]
??:? __libc_start_main [0xf762ec4]

On 02/20/2016 04:45 PM, sanjayss wrote:
> I got the following exception on a line of code that is basically "line
> = readln()" and need help in understanding what the exception is saying.
> (I am playing around with stdio prior to this using unix ioctls and
> maybe I am messing something up in the process resulting in this, but
> understanding the exception will give me a clue as to what I am doing
> wrong -- a basic D progam with readln() doesn't have the same issue).
> This is on linux with DMD version 2.07.
>
> std.stdio.StdioException@std/stdio.d(3969)
> ----------------
> ??:? void std.stdio.StdioException.opCall() [0x4c8891]
> ??:? ulong std.stdio.readlnImpl(shared(core.stdc.stdio._IO_FILE)*, ref
> char[], dchar, std.stdio.File.Orientation) [0x4c89e5]

Judging frome the fact that the exception object does not contain a message, it must be coming from one of several of the following checks:

        if (ferror(fps))
            StdioException();

For example:


https://github.com/D-Programming-Language/phobos/blob/master/std/stdio.d#L4180

And the only meaning is that the input stream is in error state. :-/

Ali

On Sunday, 21 February 2016 at 01:06:16 UTC, Ali Çehreli wrote:
> On 02/20/2016 04:45 PM, sanjayss wrote:
> > [...]
> basically "line
> > [...]
> is saying.
> > [...]
> ioctls and
> > [...]
> this, but
> > [...]
> am doing
> > [...]
> issue).
> > [...]
> std.stdio.readlnImpl(shared(core.stdc.stdio._IO_FILE)*, ref
> > [...]
>
> Judging frome the fact that the exception object does not contain a message, it must be coming from one of several of the following checks:
>
>         if (ferror(fps))
>             StdioException();
>
> For example:
>
>
> https://github.com/D-Programming-Language/phobos/blob/master/std/stdio.d#L4180
>
> And the only meaning is that the input stream is in error state. :-/
>
> Ali

Thanks. That helps. I am making the stdin non-blocking (but reverting it back before doing the readln()) -- maybe that is causing some problems. Will follow this line of reasoning to see if I can figure out the problem.

On Sunday, 21 February 2016 at 06:24:54 UTC, sanjayss wrote:
> On Sunday, 21 February 2016 at 01:06:16 UTC, Ali Çehreli wrote:
>> [...]
>
> Thanks. That helps. I am making the stdin non-blocking (but reverting it back before doing the readln()) -- maybe that is causing some problems. Will follow this line of reasoning to see if I can figure out the problem.

Just doing a "stdin.clearerr()" after switching back from non-blocking mode helped. Thanks again.