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Top Forums Programming Scanf() string pointer problem Post 302874171 by Corona688 on Thursday 14th of November 2013 11:05:39 AM
Old 11-14-2013
char *studentName; is a pointer to a string. What does it point to? Absolutely nothing and nowhere in particular. It might point to invalid memory and crash immediately. It might point to somewhere in your own stack frame, causing it to crash later in fascinating nondeterministic ways.

The correct solution would be to either
1) Use line 8
2) Point it to valid memory with a line like list[x].studentName=malloc(20);

Last edited by Corona688; 11-14-2013 at 12:16 PM..
This User Gave Thanks to Corona688 For This Post:
 

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index(3C)						   Standard C Library Functions 						 index(3C)

NAME
index, rindex - string operations SYNOPSIS
#include <strings.h> char *index(const char *s, int c); char *rindex(const char *s, int c); DESCRIPTION
The index() and rindex() functions operate on null-terminated strings. The index() function returns a pointer to the first occurrence of character c in string s. The rindex() function returns a pointer to the last occurrence of character c in string s. Both index() and rindex() return a null pointer if c does not occur in the string. The null character terminating a string is considered to be part of the string. USAGE
On most modern computer systems, you can not use a null pointer to indicate a null string. A null pointer is an error and results in an abort of the program. If you wish to indicate a null string, you must use a pointer that points to an explicit null string. On some machines and with some implementations of the C programming language, a null pointer, if dereferenced, would yield a null string. Though often used, this practice is not always portable. Programmers using a null pointer to represent an empty string should be aware of this portability issue. Even on machines where dereferencing a null pointer does not cause an abort of the program, it does not necessarily yield a null string. ATTRIBUTES
See attributes(5) for descriptions of the following attributes: +-----------------------------+-----------------------------+ | ATTRIBUTE TYPE | ATTRIBUTE VALUE | +-----------------------------+-----------------------------+ |Interface Stability |Standard | +-----------------------------+-----------------------------+ SEE ALSO
bstring(3C), malloc(3C), string(3C), attributes(5), standards(5) SunOS 5.10 24 Jul 2002 index(3C)
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