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I have my buffer as a long string from a file. Then i add word for word into a binary tree as nodes.

If i try to free my buffer when its no longer used, i get a Segmentation fault. Valgrind points out a lot of "Invalid read of size 1" errors.

If i move it down to my cleaning bracket. it works, but i get a serious memory leak (as the program can read more files).

if (argc < 2) {
    printf("No arguments was passed to proccess.\n");
    return EXIT_SUCCESS;
} else {
    for (int i = 1; i < argc; i++) {                        
        FILE *file = openFile(argv[i]);
        if (file != NULL) {
            validFiles++;
            // Get size of file and setting up a buffer
            int fileSize = getFileSize(file);
            buffer = calloc(fileSize + 1, sizeof(char));

            fread(buffer,sizeof(char),fileSize,file);
            fclose(file);
            // Break down the buffer into a tree of nodes
            pch = strtok (buffer,delimiters);       
            while (pch != NULL) {
                root = insert(root, pch, argv[i], 1);
                pch = strtok (NULL, delimiters);
            } // free(buffer); should be here
        }           
    }
}

if (validFiles > 0) {       
    searchBook(root);       
    freeTree(root);
    free(buffer); // Only frees one of the buffers when multiple files are sent in
}

Each node will allocate memory for itself inside the trees insert function.

Anders Gulowsen
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1 Answers1

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strtok will modify the buffer it gets and return pointers inside that buffer. So when you store pch returned from strtok into your binary tree it saves a part of buffer. When you then free(buffer) pch and the values in the tree become invalid, causing your invalid read errors.

Copy pch before you put it into the tree. If it's available you could use strdup. If it isn't there is a version of it here.

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Kninnug
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