| 1 | /* |
| 2 | * Simple random data generator used to create reproducible test files. |
| 3 | * This is inspired from POSIX.1-2001 implementation example for rand(). |
| 4 | * Copyright (C) 2007 by Nicolas Pitre, licensed under the GPL version 2. |
| 5 | */ |
| 6 | |
| 7 | #include "test-tool.h" |
| 8 | #include "git-compat-util.h" |
| 9 | #include "parse.h" |
| 10 | |
| 11 | int cmd__genrandom(int argc, const char **argv) |
| 12 | { |
| 13 | unsigned long count, next = 0; |
| 14 | unsigned char *c; |
| 15 | |
| 16 | if (argc < 2 || argc > 3) { |
| 17 | fprintf(stderr, "usage: %s <seed_string> [<size>]\n", argv[0]); |
| 18 | return 1; |
| 19 | } |
| 20 | |
| 21 | c = (unsigned char *) argv[1]; |
| 22 | do { |
| 23 | next = next * 11 + *c; |
| 24 | } while (*c++); |
| 25 | |
| 26 | count = ULONG_MAX; |
| 27 | if (argc == 3 && !git_parse_ulong(argv[2], &count)) |
| 28 | return error_errno("cannot parse argument '%s'", argv[2]); |
| 29 | |
| 30 | while (count--) { |
| 31 | next = next * 1103515245 + 12345; |
| 32 | if (putchar((next >> 16) & 0xff) == EOF) |
| 33 | return -1; |
| 34 | } |
| 35 | |
| 36 | return 0; |
| 37 | } |