Root/
| Source at commit 1834 created 12 years 4 months ago. By blackosx, Fix (patch) building process. Resources now download and build successfully so package can be made. Checks are now needed to see if this works on different localizations and different systems. I have a feeling more work weill be needed to handle the unicodes etc. | |
|---|---|
| 1 | /*␊ |
| 2 | * memmem.c␊ |
| 3 | *␊ |
| 4 | * Find a byte string inside a longer byte string␊ |
| 5 | *␊ |
| 6 | * This uses the "Not So Naive" algorithm, a very simple but␊ |
| 7 | * usually effective algorithm, see:␊ |
| 8 | *␊ |
| 9 | * http://www-igm.univ-mlv.fr/~lecroq/string/␊ |
| 10 | */␊ |
| 11 | ␊ |
| 12 | #include <string.h>␊ |
| 13 | ␊ |
| 14 | void *memmem(const void *haystack, size_t n, const void *needle, size_t m)␊ |
| 15 | {␊ |
| 16 | ␉const unsigned char *y = (const unsigned char *)haystack;␊ |
| 17 | ␉const unsigned char *x = (const unsigned char *)needle;␊ |
| 18 | ␊ |
| 19 | ␉size_t j, k, l;␊ |
| 20 | ␊ |
| 21 | ␉if (m > n || !m || !n)␊ |
| 22 | ␉␉return NULL;␊ |
| 23 | ␊ |
| 24 | ␉if (1 != m) {␊ |
| 25 | ␉␉if (x[0] == x[1]) {␊ |
| 26 | ␉␉␉k = 2;␊ |
| 27 | ␉␉␉l = 1;␊ |
| 28 | ␉␉} else {␊ |
| 29 | ␉␉␉k = 1;␊ |
| 30 | ␉␉␉l = 2;␊ |
| 31 | ␉␉}␊ |
| 32 | ␊ |
| 33 | ␉␉j = 0;␊ |
| 34 | ␉␉while (j <= n - m) {␊ |
| 35 | ␉␉␉if (x[1] != y[j + 1]) {␊ |
| 36 | ␉␉␉␉j += k;␊ |
| 37 | ␉␉␉} else {␊ |
| 38 | ␉␉␉␉if (!memcmp(x + 2, y + j + 2, m - 2)␊ |
| 39 | ␉␉␉␉ && x[0] == y[j])␊ |
| 40 | ␉␉␉␉␉return (void *)&y[j];␊ |
| 41 | ␉␉␉␉j += l;␊ |
| 42 | ␉␉␉}␊ |
| 43 | ␉␉}␊ |
| 44 | ␉} else␊ |
| 45 | ␉␉do {␊ |
| 46 | ␉␉␉if (*y == *x)␊ |
| 47 | ␉␉␉␉return (void *)y;␊ |
| 48 | ␉␉␉y++;␊ |
| 49 | ␉␉} while (--n);␊ |
| 50 | ␊ |
| 51 | ␉return NULL;␊ |
| 52 | }␊ |
| 53 | |
