Question

After running the program in valgrind -v it shows me that there are 3 unfreed blocks of memory (50 allocs, 47 frees). I’m probably failing to free infile outfile and temp – I guess. But when I put:

else {
        free(line);
            fclose(infile);  /* added lines */
            fclose(outfile); /* added lines */
            free(temp);      /* added lines */
        exit(EXIT_FAILURE);
} 

it doesn’t compile, showing me errors about undefined use of temp and outfile.

EDIT:
I changed it to (in lineRead):

else {
        free(line);
            fclose(infile);
            return NULL;
} 

and added following error catcher after while in main:

if ((check = readline(infile)) == NULL) {
    fclose(outfile);
}   

However, this gives me even more errors. Why is that?

/EDIT

---

How to fix that? I though that exit() does all the cleaning needed…

The code is changed in [1] because I wanted to simulate that particular error.

#include <stdio.h>
#include <stdlib.h>
#include <ctype.h>
#include <string.h>
char* lineRead(FILE* infile)
{
    char* line = NULL;
    char* newbuf = NULL;
    int c;
    size_t bufsize = 0;
    size_t size = 0;
    while((c=fgetc(infile)) != EOF) {
        if (size >= bufsize) {
        if (bufsize == 0)
                bufsize = 2;
        else if (bufsize <= ((size_t)-1)/2)
                bufsize = size+1;
        else {
                free(line);
                exit(EXIT_FAILURE);
        }
        newbuf = realloc(line,bufsize);
        if (!newbuf) {
                free(line);
                exit(EXIT_FAILURE);
        } else {
        line = newbuf;
            }
        }
        if (c != '\n') {
            line[size++]=c;
        }

    }

    if(size >= bufsize) {
        if (size > (size_t)-1)      /* [1] I know that there should be*/
                            /* '<', but it is '>' just for testing errors */
        bufsize = size + 1;
        else {
        free(line);
        exit(EXIT_FAILURE);
    }
        newbuf = realloc(line,bufsize);
        if (!newbuf) {
        free(line);
        exit(EXIT_FAILURE);
        }
        line = newbuf;
    }
    line[size++]='\0';
    return line;
}

int main(int argc, char* argv[])
{

 char *line=NULL; 
 char **lines=NULL; 
 int linenumber=0;
 int c;
 void *temp=NULL;

while((line=lineRead(infile))!=NULL) {
    linenumber++;
    temp=realloc(lines, (linenumber)*sizeof(char*));
    if(temp==NULL) {
    printf("Bad alloc error\n");
    free(lines);
    return 0;
    } else {
    lines=temp;
    }

}
/* processing lines */
free(lines);


return 0;
}

Answer 1

You didn’t free

newbuf // in read line
line // in main
temp // Which gets free'd only on after bad malloc