5 replies to this topic

[theCnewbie]

so I'm reading C for dummies, and am asked to write this code, when I go to compile it I get:

insult1.c:8: error: too few arguments to function ‘fgets’

#include <stdio.h>


int main()

{

	char jerk[20];


	printf("Give the name of a jerk you know");

	fgets(jerk);

	printf("Yeah i know %s I think he's a jerk too",jerk);

	return(0);

}

what am I doing wrong?

[dbug]

If you look at the manual for fgets function you will see that it requires 3 arguments:

char *fgets(char *s, int size, FILE *stream);

The first parameter is where the typed name will go (the jerk variable). The second one says how many characters it can read. Here you must use the size of jerk variable as a maximum (you can use the keyword sizeof() to let the compiler determine the maximum size). The last parameter must indicate from where you want to read the data. If you want to read from the keyboard, you must use stdin (it is the standard input channel).

fgets(jerk, sizeof(jerk), stdin);

[Alexander]

@dbug, fgets(jerk, 20, stdin) would be better to avoid any overflow (accept 19 + 1 null into char[20])

EDIT: Whoops, did not read that properly.

[dbug]

Isn't that what I said ? :confused:

I used sizeof(jerk) to be more flexible, but (in this case) it's the same than writing 20. Have I missed something ?

[krwq]

he means

fgets(jerk, sizeof(jerk)-1, stdin);

[dbug]

No, fgets(str, size, stream) reads at most size - 1 characters from stream. It reserves the last char to write a terminating null character.

If you use fgets(jerk, 20, stdin), it will read, at most, 19 characters from stdin.