summaryrefslogtreecommitdiffstats
path: root/software/c.page
blob: ec02db66c3f2c801f74dbf741e27eb9ea54a5aff (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44

C Programming Language
=======================

K&R Notes (unstructured)
-----------------------------

With pointer arithmatic, the type of ``foo *p`` is taken into account
automagically. Eg, ``p+3`` -> ``0xFEFE0000 + 3 * (sizeof foo)``.

Examples of tricky pointer sytax::

    int *ip;  
    (++*p)
    (*p++)
    ++(*p)
    *(++p)

In the context of references like function declarations, only the size of the
first dimension of a multi-dimensional array is free; the others must be
specified explicitly::

    void copy_2d_array(int a[][10], int b[][10]); // Ok
    void copy_2d_array(int a[][],   int b[][]);   // Invalid
    void copy_2d_array(int a[10][], int b[10][]); // Invalid

Negative indexing of arrays is "allowed" (reads ahead of the array in memory);
need to check for that case explicitly.

``_FORTIFY_SOURCE`` does what it says. 

In C99 can ``int* p`` replace ``int *p``? Seems like yes. 

The "update statement" of a for loop gets executed at the /end/ of every loop,
which means an iteration variable gets updated once more than might be
expected::

    int i;
    for(i = 0; i < 10; i++) { 
        } 
    printf("%d\n", i); // prints 10, not 9

Any 'inline' should probably be 'static' (local linkage).