leak in fgets when assigning to buffer
- by monkeyking
I'm having problems understanding why following code leaks in one case, and not in the other case.
The difference is
while(NULL!=fgets(buffer,length,file))//doesnt leak
while(NULL!=(buffer=fgets(buffer,length,file))//leaks
I thought it would be the same.
Full code below.
#include <stdio.h>
#include <stdlib.h>
#define LENS 10000
void no_leak(const char* argv){
char *buffer = (char *) malloc(LENS);
FILE *fp=fopen(argv,"r");
while(NULL!=fgets(buffer,LENS,fp)){
fprintf(stderr,"%s",buffer);
}
fclose(fp);
fprintf(stderr,"%s\n",buffer);
free(buffer);
}
void with_leak(const char* argv){
char *buffer = (char *) malloc(LENS);
FILE *fp=fopen(argv,"r");
while(NULL!=(buffer=fgets(buffer,LENS,fp))){
fprintf(stderr,"%s",buffer);
}
fclose(fp);
fprintf(stderr,"%s\n",buffer);
free(buffer);
}
