strcat simulation in c

Question

#include<stdio.h>

main()
{
    char *str1="beautiful";
    char *str2="place";
    xstrcat(str1,str2);
}

xstrcat(char *s1,char *s2)
{

    char *temp;
    temp=s1;

    while(*s1!='\0')
    {
        s1++;
    }
    while(*s2!='\0')
    {
        s1++;
        *s1=*s2;
        s2++;
    }
    s1++;
    *s1='\0';
    printf("\n%s",temp);
}

Error output: Program received signal SIGSEGV, Segmentation fault. 0x000000000040055d in xstrcat (s1=0x400696 "place", s2=0x400696 "place") at strcat.c:23 23 *s1=*s2;

I am not able to write in that memory. Can anyone please tell why i am getting this error. ?

@apprentice - Those kind of improvements should be posted as an *answer*. Fixing up the *question* kind of defeats [the purpose of SO](http://stackoverflow.com/about) ... ;-) Plus the context is lost, so none of the responses/comments make sense any more. — Leigh, May 31 '13 at 19:35

score 0 · Accepted Answer · answered May 31 '13 at 15:43

0

str1 is a string literal it is undefined behavior to write to that location. It would be valid to create and write to str1 if it was defined like this:

char str1[100] = "beautiful";

answered May 31 '13 at 15:43

Shafik Yaghmour

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why is it store it as const without we declared?? – user1762571 May 31 '13 at 18:08
@user1762571 Please read this: http://stackoverflow.com/a/2589974/1708801 – Shafik Yaghmour May 31 '13 at 18:22

strcat simulation in c

1 Answers1