UMBC CS 201, Spring 02
UMBC CMSC 201 Spring '02 CSEE | 201 | 201 S'02 | lectures | news | help

scanf2

Our second example shows the consequence of forgetting the & in front of the variable passed to scanf: you get garbage and although it didn't happen this time, you can and sometimes do get a segmentation fault - core dump.

The Program

/********************************************** * File: scanf2.c * Author: Sue Bogar * Date: 2/2/98 * Section: 101 * SSN: 123-45-6789 * EMail: bogar@cs.umbc.edu * * This program demonstrates the use * of the scanf function. **********************************************/ #include <stdio.h> int main ( ) { int n ; printf("Enter an integer: ") ; scanf("%d", n) ; printf("n = %d\n", n) ; return 0; }

The Sample Run

linux3[88] % gcc -Wall -ansi scanf2.c scanf2.c: In function `main': scanf2.c:21: warning: format argument is not a pointer (arg 2) linux3[89] % a.out Enter an integer: 5 n = 134517984 linux3[90] % !a a.out Enter an integer: 7 n = 134517984 linux3[91] %


CSEE | 201 | 201 S'02 | lectures | news | help

Thursday, 17-Jan-2002 13:52:24 EST