what is wrong in this program... its giving segmentation fault......
Code:#include <stdio.h> main() { FILE *fp; char *ch; int n; if((fp = fopen("./stuf", "r+")) != NULL) printf("no problem\n"); else printf("problem\n"); while(fread(ch, 1, 1, fp)) { printf("not entering\n"); printf("%c\n", *ch); } }
1. main should be
int main(void) - read FAQ
2. when fopen failed you continue to the read part anyway
3. ch is uninitialized pointer to char - you cannot write where (you do not know where it points
better use
char ch;
fread(&ch,1,1,fp);
4. for reading just one char fgetc seems to be more suitable
All problems in computer science can be solved by another level of indirection,
except for the problem of too many layers of indirection.
– David J. Wheeler
Well 3 problems...
First, if fopen() fails, you just print an error message and then continue trying to read from a bad file handle.
Second, in this line:
ch is a char* pointer, but you never malloc any space for it, but instead just use it as if it were a valid pointer, then on top of that you de-reference the bad pointer here:Code:while(fread(ch, 1, 1, fp))
Edit: Oh, vart beat me to it, and yeah, main() should return an int.Code:printf("%c\n", *ch);
"I am probably the laziest programmer on the planet, a fact with which anyone who has ever seen my code will agree." - esbo, 11/15/2008
"the internet is a scary place to be thats why i dont use it much." - billet, 03/17/2010
thank you i got it....
