Something wrong with the output!

[kradragon94]

I want to edit the text file so it has more space between successive lines, but there are some weird characters also added at the beginning of the file, which i dont know why.

Help me correct my code, thank very much :)

#include <stdio.h>
#include <string.h>

int main()
{
  FILE* fFile;
  char str[50], editedContent[500];

  if ((fFile = fopen("lab2.txt", "r+")) == NULL)
    {
      printf("Can not open file for reading.\n");
      return 1;
    }
  while (fgets(str, 50, fFile) != NULL)
    {
      strcat(editedContent, str);
      strcat(editedContent, "\n");
    }

  //reset position to the beginning of the file and write new content
  rewind(fFile);
  fputs(editedContent, fFile);

  fclose(fFile);
  return 0;
}

This is the content of lab2.txt before and after editing:

1
2
3
4
5

4³p·1

2

3

4

5

[abhishekm71]

Try initializing editedContent with empty string.

char s[]="";
strcpy ( editedContent, s );

[kradragon94]

It worked, thank :)
But I still dunno why is that, this example I read below still work without initializing string

http://www.cplusplus.com/reference/cstring/strcat/

[cire]

abhishekm71 wrote:

Try initializing editedContent with empty string.

char s[]="";
strcpy ( editedContent, s );

Better would be to use actual initialization:
char str[50]={}, editedContent[500]={};

kradragon94 wrote:

But I still dunno why is that, this example I read below still work without initialize the string

strcpy does not rely on the contents of the destination string.

[abhishekm71]

ok.. thanx cire, for pointing out the simpler option.
Didn't know that even char arrays could be initialized in such a manner.