int a[10000];
for(int i=0;i<10000;i++)
{
a[i]=i; cout<<a[i]<<endl;
}
Suppose this is the code and on the terminal screen I need all outputs (0-9999) But it only displays (9704-9999) at the end
I want to see all the numbers on the terminal window but it removes the upper part of the data. I guess I have to change some settings.
Increase the console buffering. Depending on which terminal you're using it'll be different. For example on Windows conhost.exe is the default console used by cmd and PowerShell. Just click the icon on the top left > Properties > Layout and set Screen Buffer Size to a large enough number
But the better solution would be redirecting to file, because no one wants to read 10000 lines on the console, and there's no guarantee that the console will have a buffer of infinite length or length of more than 10000 lines. conhost for example only supports maximum 9999 lines so you'll miss at least the command you typed and the first output line. Besides that'll often remove other commands' output from the history which is undesirable
Either do that from the command line with the redirection operator >
yourapp.exe >output.txt
or save to file directly from your code
Related
Hello I'm trying to build a function grapher on the terminal in c++. I want that every time a new function is added the output will be cleared and the new frame will take its place.
I've tried to do system("clear") but I don't want all the terminal to be cleared and only the output stream. I've also thought about printing '\b' a lot of times but that seems inefficient.
I would also like to know how to delete 1 line.
You may try to work with console code.
Console code about cursor
There are two solution.
Here is some C style code, just to demonstate the idea easier, you may convert it into C++ style.
Clear content
//Clear content after (x,y)
printf("\033[%d,%dH\033[J",y,x);
//x the column number,y the row number
Overwrite the content
//Goto (x,y) then print the next frame, it should overwrite the old content
printf("\033[%d,%dH",y,x);
...
//your code to output the next frame
In my output there are certain lines that are refreshed every few seconds. If I resize the terminal by clicking F11, then output is just as I wanted. If terminal isn't big enough some long lines that are refreshed are splitted in two, and because of that, only one part of line is refreshed, and every time line is refreshed I also get new line.
This could be easily avoided if I could specify default size of terminal (resize terminal from my program). Also it would be great if I could forbid user to change terminal size while program is running.
while(1)
{
cout<<"Long line that is refreshed every 5s... \r";
//if line is splited in two lines, \r will return to beginning of that new line
//and the first part of original line would stay as it is(won't be rewrited)
sleep(5);
}
How do I specify a terminal size or stop terminal resizing?
Some terminal emulators (including the default macOS Terminal.app) support being resized/moved/etc in response to printed control sequences. The sequences are fairly standard but not all terminal emulators implement all of them.
For example:
# set terminal width to 50, height to 100
cout << "\e[8;50;100t";
This answer includes an overview of some other available control sequences.
I don't think you can forbid the user to change the terminal size. A better way would be to catch the SIGWINCH signal that is sent to the process everytime the window size is changed, and use the TIOCGWINSZ / TIOCGSIZE ioctl() to get the dimensions.
I'm a Vim user and don't know much about Emacs. I'm interested with Emacs because I find that debugging within Emacs is more pleasant. For example, it provides syntax highlighting and I can set breakpoints with the mouse.
Everything works well except when printf is encountered.
Simple code for illustration:
1 #include <stdio.h>
2
3 int main()
4 {
5 int a = 1;
6 printf("%d\n", a);
7 int b = 2;
8 return 0;
9 }
emacs main.c
left click on the bottom half
M-x gdb[return][return]
(gdb) b 6
(gdb) r
By now, the source codes are showed in the upper half, and gdb prompt in the bottom half. This is exactly what I want.
(gdb) n
Now the source codes disappear, and the upper half is used to show stdout instead. This is really inconvenient. I'd like the stdout to show in the gdb buffer, and the sources stay in the upper buffer, just as the gdb -tui mode.
Instead of manually setting up your splits each time, try telling GDB which windows you want available.
For example:
;; Show main source buffer when using GDB
(setq gdb-show-main t)
Now you can simply use M-x gdb to start GDB, and it should keep your source code buffer displayed in a split window.
Incidentally, Emacs' GDB interface supports a number of other windows that you may want to enable:
If gdb-many-windows is non-nil, then M-x gdb displays the
following frame layout:
+--------------------------------+--------------------------------+
| GUD interaction buffer | Locals/Registers buffer |
|--------------------------------+--------------------------------+
| Primary Source buffer | I/O buffer for debugged pgm |
|--------------------------------+--------------------------------+
| Stack buffer | Breakpoints/Threads buffer |
+--------------------------------+--------------------------------+
If you ever change the window layout, you can restore the "many
windows" layout by typing M-x gdb-restore-windows. To toggle between
the many windows layout and a simple layout with just the GUD
interaction buffer and a source file, type M-x gdb-many-windows.
You may also specify additional GDB-related buffers to display,
either in the same frame or a different one. Select the buffers you
want by typing M-x gdb-display-BUFFERTYPE-buffer or M-x gdb-frame-BUFFERTYPE-buffer, where BUFFERTYPE is the relevant buffer
type, such as breakpoints. You can do the same with the menu bar,
with the GDB-Windows and GDB-Frames sub-menus of the GUD menu.
When you finish debugging, kill the GUD interaction buffer with C-x k,
which will also kill all the buffers associated with the session.
However you need not do this if, after editing and re-compiling your
source code within Emacs, you wish to continue debugging. When you
restart execution, GDB automatically finds the new executable. Keeping
the GUD interaction buffer has the advantage of keeping the shell
history as well as GDB's breakpoints. You do need to check that the
breakpoints in recently edited source files are still in the right
places.
You might also like to try M-x gud-gdb. It's a much more bare-bones UI, but I personally prefer it.
I use the following lines to output my simulation's progress info in my c++ program,
double N=0;
double percent=0;
double total = 1000000;
for (int i; i<total; ++i)
{
percent = 100*i/total;
printf("\r[%6.4f%%]",percent);
}
It works fine!
But the problem is I see the terminal cursor keeps blinking cyclically through the numbers, this is very annoying, anyone knows how to get rid of this?
I've seen some programs like wget or ubuntu apt, they use progress bar or percentages too, but they seems no blinking cursor issue, I am wondering how did they do that?
Thanks!
You can hide and show the cursor using the DECTCEM (DEC text cursor enable mode) mode in DECSM and DECRM:
fputs("\e[?25l", stdout); /* hide the cursor */
fputs("\e[?25h", stdout); /* show the cursor */
Just a guess: try to use a proper number of '\b' (backspace) characters instead of '\r'.
== EDIT ==
I'm not a Linux shell wizard, but this may work:
system("setterm -cursor off");
// ...display percentages...
system("setterm -cursor on");
Don't forget to #include <cstdlib> or <iostream>.
One way to avoid a blinking cursor is (as suggested) to hide the cursor temporarily.
However, that is only part of the solution. Your program should also take this into account:
after hiding the cursor and modifying the screen, before showing the cursor again move it back to the original location.
hiding/showing the cursor only keeps the cursor from noticeably blinking when your updates take only a small amount of time. If you happened to mix this with some time-consuming process, your cursor will blink.
The suggested solution using setterm is not portable; it is specific to the Linux console. And running an executable using system is not really necessary. But even running
system("tput civis");
...
system("tput cnorm");
is an improvement over using setterm.
Checking the source-code for wget doesn't find any cursor-hiding escape sequences. What you're seeing with its progress bar is that it leaves the cursor in roughly the same place whenever it does something time-consuming. The output to the terminal takes so little time that you do not notice the momentary rewrite of the line (by printing a carriage return, then writing most of the line over again). If it were slower, then hiding the cursor would help — up to a point.
By the way — this cursor-hiding technique is used in the terminal drivers for some editors (vim and vile).
Those apps are probably using ncurses. See mvaddstr
The reason the cursor jumps around is because stdout is buffered, so you don't know actually how many characters are being printed at some point in time. The reason wget does not have a jumping cursor is that they are actually printing to stderr instead, which is unbuffered. Try the following:
fprintf(stderr, "\r[%6.4f%%]", percent);
This also has the advantage of not cluttering the file if you are saving the rest of the output somewhere using a pipe like:
$ ./executable > log.data
Press insert key...if that doesn't work then press the fn key in your keyboard.
This will definitely work
Hope this helps
Actually I have trouble naming the title of this post. Because I don't know how to summarize my meaning in a professional way. But I'll explain my question as below:
I'm running a program written by C++, command is:
./VariationHunter_SC
Then it'll let you type in many parameters:
Please enter the minimum paired-end insert size:
Please enter the maximum paired-end insert size:
Please enter the pre-processing mapping prune probability:
Please enter the name of the input file:
Please enter the minimum support for a cluster:
Obviously I need to type in such parameters one by one to run the program; But I have thousands of such jobs, and need to pre-assign such parameters in script, and submit script to computer.
So how can I do that?
thx
Edit
so how can I make parameter-list?
Just like below?:
140
160
0
mrfast.vh
1
Seems the program cannot recognize these numbers, and distribute numbers..
This depends on how the program actually reads the data that you type in - it's likely that its reading stdin, so you could use separate files with the parameters and pass them in via redirection: ./VariationHunter_SC < parameter-file
It's also possible that the program will accept parameters on the command line, but there's no way of really knowing that (or how) except by whatever documentation the program might come with (or by reading the source code, if it's available and there is no other accurate docs).
Simply use the piping character to pipe the contents of a file to your program
example, in a windows command shell:
echo "asdf" | pause
This will pass "asdf" to the pause program. As a result, pause will print a "Press any key to continue" message, then imediately continue because it will receive the "asdf" string as a response.
So, overall, write or use a program that outputs the contents of your file. Call it, then pipe its output to the program that needs the input.
The unix cat command is such a command that writes the contents of a file to output, or to the input of another executable if you are piping the output.