Re: basic interactive readf from stdin
On Saturday, 26 December 2015 at 20:11:27 UTC, karthikeyan wrote: I experience the same as the OP on Linux Mint 15 with dmd2.069 and 64 bit machine. I have to press enter twice to get the output. I read http://ddili.org/ders/d.en/input.html and inserted a space before %s but still no use. Am I missing something here with the latest version? Oh, I'm sorry, it isn't buffering, it is readfing into a string here which is weird. Maybe try readln instead of readf.
basic interactive readf from stdin
Simple VS console app in D. Reading lines to a string variable
interactively. Object is to have no extra blank lines in the
console output. Seems very broken for this use, requiring two
extra "enter" entries before the outputs both appear. Version
DMD32 D Compiler v2.069.2
import std.stdio;
int main(string[] argv)
{
string nm;
stdin.readf("%s\n",);
writeln("nm:",nm);
stdin.readf("%s\n",);
writeln("nm:",nm);
return 0;
}
io shown below
123
456
nm:123
nm:456
Re: basic interactive readf from stdin
On Saturday, 26 December 2015 at 19:40:59 UTC, Jay Norwood wrote: Simple VS console app in D. If you are running inside visual studio, you need to be aware that output will be block buffered, not line buffered, because VS pipes the output making the program think it is talking to another program instead of to an interactive console (well, because it is!) Add a stdout.flush(); after writing to force it to show immediately. I really think the read functions ought to flush output too because this is such a FAQ. (indeed, my terminal.d does flush output when you request input)
Re: basic interactive readf from stdin
On Saturday, 26 December 2015 at 19:52:15 UTC, Adam D. Ruppe
wrote:
On Saturday, 26 December 2015 at 19:40:59 UTC, Jay Norwood
wrote:
Simple VS console app in D.
If you are running inside visual studio, you need to be aware
that output will be block buffered, not line buffered, because
VS pipes the output making the program think it is talking to
another program instead of to an interactive console (well,
because it is!)
Add a stdout.flush(); after writing to force it to show
immediately. I really think the read functions ought to flush
output too because this is such a FAQ. (indeed, my terminal.d
does flush output when you request input)
I experience the same as the OP on Linux Mint 15 with dmd2.069
and 64 bit machine. I have to press enter twice to get the
output. I read http://ddili.org/ders/d.en/input.html and inserted
a space before %s but still no use. Am I missing something here
with the latest version?
Code
import std.stdio;
int main(string[] argv)
{
string nm;
readf(" %s\n",);
writeln("nm:",nm);
// readf(" %s\n",);
// writeln("nm:",nm);
return 0;
}
Output
56
2
nm:56
Re: basic interactive readf from stdin
On Saturday, 26 December 2015 at 20:19:08 UTC, Adam D. Ruppe wrote: On Saturday, 26 December 2015 at 20:11:27 UTC, karthikeyan wrote: I experience the same as the OP on Linux Mint 15 with dmd2.069 and 64 bit machine. I have to press enter twice to get the output. I read http://ddili.org/ders/d.en/input.html and inserted a space before %s but still no use. Am I missing something here with the latest version? Oh, I'm sorry, it isn't buffering, it is readfing into a string here which is weird. Maybe try readln instead of readf. As far as I remember, in C, if I was to be putting "\n" in scanf after %s, that double entering was happening. I guess that's the same problem. Trying same code without \n in readf can fix it I guess.
Re: basic interactive readf from stdin
On Saturday, 26 December 2015 at 20:19:08 UTC, Adam D. Ruppe
wrote:
On Saturday, 26 December 2015 at 20:11:27 UTC, karthikeyan
wrote:
I experience the same as the OP on Linux Mint 15 with dmd2.069
and 64 bit machine. I have to press enter twice to get the
output. I read http://ddili.org/ders/d.en/input.html and
inserted a space before %s but still no use. Am I missing
something here with the latest version?
Oh, I'm sorry, it isn't buffering, it is readfing into a string
here which is weird. Maybe try readln instead of readf.
The use of readf into a string is demonstrated in a stdio.d unit
test. I assumed it might also work with stdin.
string s;
auto f = File(deleteme);
f.readf("%s\n", );
assert(s == "hello", "["~s~"]");
f.readf("%s\n", );
assert(s == "world", "["~s~"]");
=
I did get this below to work with readln, although since readln
didn't consume the terminator, I had to add the chomp() call.
import std.stdio;
import std.string;
int main(string[] argv)
{
string nm, nm2;
nm=readln('\n');
nm2 = nm.chomp();
writeln("nm:",nm2);
nm=readln('\n');
nm2 = nm.chomp();
writeln("nm:",nm2);
return 0;
}
Re: basic interactive readf from stdin
On Sunday, 27 December 2015 at 00:20:51 UTC, Ali Çehreli wrote: On 12/26/2015 12:11 PM, karthikeyan wrote: > I read http://ddili.org/ders/d.en/input.html and inserted a space before %s > but still no use. Am I missing something here with the latest version? The answer is nine chapters later. :) (Use readln() and strip() (or chomp())). http://ddili.org/ders/d.en/strings.html Ali Many thanks Ali. The book says ctrl + D to end input. But I used two enters to get the output. Any idea why? The book was great. Thanks a lot.
Re: basic interactive readf from stdin
On 12/26/2015 11:40 AM, Jay Norwood wrote:
Simple VS console app in D. Reading lines to a string variable
interactively. Object is to have no extra blank lines in the console
output. Seems very broken for this use, requiring two extra "enter"
entries before the outputs both appear. Version DMD32 D Compiler v2.069.2
import std.stdio;
int main(string[] argv)
{
string nm;
stdin.readf("%s\n",);
writeln("nm:",nm);
stdin.readf("%s\n",);
writeln("nm:",nm);
return 0;
}
io shown below
123
456
nm:123
nm:456
Reading lines with readln works in a Linux console:
import std.stdio;
import std.string;
int main(string[] argv)
{
string nm;
nm = readln.strip;
writeln("nm:",nm);
nm = readln.strip;
writeln("nm:",nm);
return 0;
}
Ali
Re: basic interactive readf from stdin
On 12/26/2015 05:15 PM, Karthikeyan wrote: >> The answer is nine chapters later. :) (Use readln() and strip() (or >> chomp())). >> >> http://ddili.org/ders/d.en/strings.html >> >> Ali > > Many thanks Ali. The book says ctrl + D to end input. But I used two > enters to get the output. Any idea why? I guess that means that my understanding was not portable. It requires Ctrl-D on my console environment on Linux. No matter how many Enters I enter :p they become parts of the same string. Ali
Re: basic interactive readf from stdin
On Saturday, 26 December 2015 at 19:52:15 UTC, Adam D. Ruppe wrote: On Saturday, 26 December 2015 at 19:40:59 UTC, Jay Norwood wrote: Simple VS console app in D. If you are running inside visual studio, you need to be aware that output will be block buffered, not line buffered, because VS pipes the output making the program think it is talking to another program instead of to an interactive console (well, because it is!) Add a stdout.flush(); after writing to force it to show immediately. I really think the read functions ought to flush output too because this is such a FAQ. (indeed, my terminal.d does flush output when you request input) It doesn't make a difference if I run in VS or from a console window. I had also already tried various forms stdout.flush(). It doesn't make a difference ... still requires two extra enters before it outputs the data. I haven't tried it in linux yet.
Re: basic interactive readf from stdin
On Saturday, 26 December 2015 at 20:38:52 UTC, tcak wrote:
On Saturday, 26 December 2015 at 20:19:08 UTC, Adam D. Ruppe
wrote:
On Saturday, 26 December 2015 at 20:11:27 UTC, karthikeyan
wrote:
I experience the same as the OP on Linux Mint 15 with
dmd2.069 and 64 bit machine. I have to press enter twice to
get the output. I read http://ddili.org/ders/d.en/input.html
and inserted a space before %s but still no use. Am I missing
something here with the latest version?
Oh, I'm sorry, it isn't buffering, it is readfing into a
string here which is weird. Maybe try readln instead of readf.
As far as I remember, in C, if I was to be putting "\n" in
scanf after %s, that double entering was happening. I guess
that's the same problem. Trying same code without \n in readf
can fix it I guess.
import std.stdio;
int main(string[] argv)
{
string nm;
stdin.readf("%s",);
writeln("nm:",nm);
stdout.flush();
stdin.readf("%s",);
writeln("nm:",nm);
stdout.flush();
return 0;
}
ok, I tried above, adding both the stdout.flush() and removing
the \n from the format. It didn't write to output even after a
couple of enter's. When I entered ctrl-Z, it output below.
output running from command prompt
123
456
^Z
nm:123
456
nm:123
456
Re: basic interactive readf from stdin
On Sunday, 27 December 2015 at 00:20:51 UTC, Ali Çehreli wrote: On 12/26/2015 12:11 PM, karthikeyan wrote: > I read http://ddili.org/ders/d.en/input.html and inserted a space before %s > but still no use. Am I missing something here with the latest version? The answer is nine chapters later. :) (Use readln() and strip() (or chomp())). http://ddili.org/ders/d.en/strings.html Ali Yes, thank you, strip() appears to be more useful than chomp() in this case.
Re: basic interactive readf from stdin
On Sunday, 27 December 2015 at 02:08:05 UTC, Ali Çehreli wrote: On 12/26/2015 05:15 PM, Karthikeyan wrote: >> The answer is nine chapters later. :) (Use readln() and strip() (or >> chomp())). >> >> http://ddili.org/ders/d.en/strings.html >> >> Ali > > Many thanks Ali. The book says ctrl + D to end input. But I used two > enters to get the output. Any idea why? I guess that means that my understanding was not portable. It requires Ctrl-D on my console environment on Linux. No matter how many Enters I enter :p they become parts of the same string. Ali :) I was on zsh with gnome terminal alike on Linux Mint 15. Thanks for clearing that up.
Re: basic interactive readf from stdin
On 12/26/2015 12:11 PM, karthikeyan wrote: > I read http://ddili.org/ders/d.en/input.html and inserted a space before %s > but still no use. Am I missing something here with the latest version? The answer is nine chapters later. :) (Use readln() and strip() (or chomp())). http://ddili.org/ders/d.en/strings.html Ali
