How to scan a string and write it in a file?

Question

I want to scan a string that a user inputs, then write it into the file (file.txt), but this doesn't seem to work for some reason

int main()
{
    FILE *stream;

    stream = fopen("file.txt", "w");

    char str[] = { '\0 ' };
    scanf("%s", &str);
    fprintf(stream, "%s.\n", str);


    fclose(stream);

    return(0);
}

Is str long enough? Does scanf prevent more than 20 characters to be read — Ed Heal
– Ed Heal, Commented Apr 12, 2017 at 21:12

Vaduva Mihaita Bogdan · Accepted Answer · 2017-04-12 21:25:44Z

3

try this, should work just fine. It did for me so it should for you too.

#include <stdio.h>
#include <string.h>

int main()
{
FILE *stream;

stream = fopen("ceva.txt", "w");
if (stream == NULL) {
   perror("Failed: ");
   return 1;
}
char str[250];
scanf("%249s", str);
fprintf(stream, "%s.\n", str);


fclose(stream);

return 0;}

edited Apr 12, 2017 at 21:25

answered Apr 12, 2017 at 21:16

Vaduva Mihaita Bogdan

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5 Comments

Ed Heal Over a year ago

Change scanf("%s", str); to scanf("%249s", str);

Vaduva Mihaita Bogdan Over a year ago

Yes, thank you, guys. I just did it to present a code that works for the purpose of printing into a file something read from the keyboard. I just rushed in and forgot. Thanks again

Ed Heal Over a year ago

Perhaps also check stream is not null as well

chux Over a year ago

Robust code always checks the return value of input functions. if (scanf("%249s", str) == 1) fprintf(stream, "%s.\n", str);

Meixner Over a year ago

In most cases scanf("%s",...) is not what most users want to use since scanf("%s") just reads words terminated by whitespace, which is quite confusing in many situations, e.g. pressing ENTER does not make it return since ENTER is whitespace. In many cases you are better off with using fgets().

Stefano · Accepted Answer · 2017-04-13 12:21:26Z

0

You must change scanf with fscanf

answered Apr 13, 2017 at 12:21

Stefano

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