CODEWITHSUNDEEP
c++printf
Verance
Verance

Reputation: 137

Printf doesnt pop

I'm new to programming in c++ and I'm facing a problem following lynda.com tutorials. It seems okay on the tutorial video but this isnt working with me. 

#include <stdio.h>

enum { max_string = 127 };

static char string[max_string + 1 ] = "";

int main( int argc, char ** argv ) {
    printf("Type a string: ");
    fgets(string, max_string, stdin);
    printf("The string is %s", string);
    return 0;
}

And when I run this something blank appears and I need when I right something like "hey" in the blanket space, this happens:

hey
Type a string: The string is hey

This is completely strange for me and I have no idea what Im doing wrong tbh. I'm using Eclipse btw.

Could someone help me out?

Upvotes: 0

Views: 229

Answers (1)

Keith Thompson
Keith Thompson

Reputation: 263657

It appears that your standard output stream is line-buffered, meaning that text you print doesn't appear until you've printed a complete line. It should be unbuffered if you're writing to an interactive device; perhaps something is preventing the system from being aware that the output device is interactive.

Adding

fflush(stdout);

after your first printf should force the "Type a string: " prompt to appear immediately (and even if your output is unbuffered, fflush(stdout) is harmless).

I was about to suggest changing your second printf from:

printf("The string is %s", string);

to:

printf("The string is %s\n", string);

to ensure that your program's output ends with a newline (some systems can misbehave if it isn't) -- but fgets() actually leaves the newline in your string (unless the input line was very long). Eventually you'll want to be able to deal with that kind of thing.

Upvotes: 2

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