Segmentation fault while file copy in unix - c

Question

I am writing to copy text from one file to another in unix using C lang. Below is a a part of my code. when i execute the program i am getting Segmentation fault error.
Any help appreciated..
#include<fcntl.h>
#include<unistd.h>
#include<stdio.h>
int main (int argc, char *argv[])
{
char buffer[BUFFSIZE];
int infile;
int outfile;
int n;
size_t size;
printf("Enter the Source file name: \n");
scanf("%s",&argv[1]);
printf("Enter the Destination file name : \n");
scanf("%s", &argv[2]);
if((infile = open(argv[1], O_RDONLY,0)) < 0)
{
perror("Source file does not exist");
return -1;
}
if((outfile=open(argv[2],O_WRONLY,0644))>0)
{
printf("Target/Destination File Exists:\n \n ");
//printf("Target Fiel Exists , Do you wish to Overwrite or Appened Data to it: \n \n 1=Yes(Overwrite),\n 0=No(Append):\n");
scanf("%d",&n);
if(n==1)
{
if((outfile=open(argv[2],O_WRONLY|O_CREAT |O_EXCL, 0644)>=0))
{
printf("File is Being opened in Overwrite Mode: \n \n");//File is overwrited
}
}
}
}

Answer 1

It's very, very unusual to read data into your argv array. You probably shouldn't think about doing that.
Even if you really wanted to do that, the following would still be wrong:
scanf("%s",&argv[1]);
The elements of argcv are pointers to strings, so that function call will read a string into the memory that stores a pointer. The argv[1] elemetn will be invalid, adn in all likelihood the string that is input will overrun and trash one or more elements after that one.
Try something like:
char infile_name[81];
char outfile_name[81];
printf("Enter the Source file name: \n");
scanf("%80s", infile_name);
printf("Enter the Destination file name : \n");
scanf("%80s", outfile_name);
And adjust the rest of the references to argv[1] and argv[2].