CODEWITHSUNDEEP
cdebuggingmemory-managementprintf
user2127579
user2127579

Reputation: 31

fprintf causes console application to crash

I'm debugging a problem with fprintf. I was hoping you guys can give me some advice or even if it is a simple problem then help me identify it. My code is as follows.

        while(fgets(buffer, 500, filep) != NULL){
        //printf("%d\n", i);
        strcpy(result, buffer);
        result = strtok(result, " ,()[]\'");
        //printf("%s\n", buffer);
        while(result != NULL){
            //printf("%s\n", buffer);
            if(stricmp(result, strng) == 0){
                //printf("found!!\n");
                printf("%s\n", buffer);
                fprintf(Compilation, "%s", buffer);
                //printf("%s", result);
            }
            result = strtok (NULL, " ,()[]\'");
        }
        result = (char*)realloc(result, 500);
    }

I know this is messing and perhaps not even the best way to go at it but it is what I have. buffer and result are originially malloced with 1024 bytes. once each line is parsed, if a string is found within the line then the whole line is appended to a new file. I know the memory is messy so I'm still trying to tighten it up. My problem is that fprintf will run for many lines and once in awhile it will hit a line and crash the application. When I debug this problem in the IDE (VSexpress2012) with the printf line then I see that printf actually prints many lines after fprintf stops printing to the file. Any help will be appreciated.

Upvotes: 0

Views: 1369

Answers (1)

Dark Falcon
Dark Falcon

Reputation: 44181

You can't pass an arbitrary pointer into realloc. The problem is that strtok modifies the result pointer, then you attempt to realloc using this pointer. realloc needs the original pointer returned from malloc.

Upvotes: 2

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