Hi
I write some programm which reading data from stdin until EOF
and i programm doesn't recognize CTRL+Z i have to press it 3 or 4 times and then while is terminated. Can you tell me please where is mistake and why it is happen?Code:while (scanf("%s",slowo)!=EOF) { do something }
Which OS are you on?
It's typically ctrl-z for DOS/Windows and ctrl-d for Linux/Unix.
When do you signal EOF?
hello<ctrl-z>
is not the same as
hello
<ctrl-z>
If you dance barefoot on the broken glass of undefined behaviour, you've got to expect the occasional cut.
If at first you don't succeed, try writing your phone number on the exam paper.
I am using windows. The purpose of this programm is to reading data from input until EOF. Input can be number or characters such as +, - and other arithmetic and bitwise operators. That is the reason that i am using scanf. when i am typing for example
1234/n
33/n
43/n
it works properly but i have to press few times CTRL+Z until programm break the while loop
I think on Windows you need to not only enter ctrl-Z as the first "character" on a new line but you also need to press Enter after it.
If I recall, hex 0x1a (which, being decimal 26, is ctrl-Z) is used as an actual character in a text file that can indicate the end of the file (at least for some programs, such as type). So it seems it's treated as an actual character rather than a signal.
Last edited by john.c; 11-25-2021 at 01:17 PM.
A little inaccuracy saves tons of explanation. - H.H. Munro
It would be interesting if someone on Windows could test the following which creates a text file called ctrlz.txt. Once it's created, try "typing" it out in the console with the command type ctrlz.txt to see if it only prints the first two lines.
Code:#include <stdio.h> int main() { FILE *fout = fopen("ctrlz.txt", "w"); fprintf(fout, "line one\nline two\n\x1a\nline three\nline four\n"); fclose(fout); return 0; }
A little inaccuracy saves tons of explanation. - H.H. Munro
Yes it prints only the first 2 lines.
Nothing work properly even if i will compare slowo[0] to 0x1a.
Thanks thmm. That's interesting.
gawiellus, nobody asked you to compare slowo[0] to 0x1a. It is not common for an actual 0x1a to be in the file data. That was just an experiment.
How about:
To end the input enter Ctrl-Z on a separate line, follwed by the Enter key.Code:char slowo[256]; while (fgets(slowo, sizeof slowo, stdin) != NULL) { // do something (remembering that slowo retains the newline) }
A little inaccuracy saves tons of explanation. - H.H. Munro
I have to use scanf function. It is weird because
works well in linuxCode:while(scanf("%s",slowo)!=EOF)
