2 * This file is part of vbig.
3 * Copyright (C) 2011 Richard Kettlewell
5 * This program is free software: you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation, either version 3 of the License, or
8 * (at your option) any later version.
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
15 * You should have received a copy of the GNU General Public License
16 * along with this program. If not, see <http://www.gnu.org/licenses/>.
30 // Command line options
31 const struct option opts[] = {
32 { "seed", required_argument, 0, 's' },
33 { "verify", no_argument, 0, 'v' },
34 { "create", no_argument, 0, 'c' },
35 { "flush", no_argument, 0, 'f' },
36 { "help", no_argument, 0, 'h' },
37 { "version", no_argument, 0, 'V' },
41 // Display help message
42 static void help(void) {
43 printf("vbig - create or verify a large but pseudo-random file\n"
46 " vbig [--seed SEED] --verify|--create PATH [SIZE]\n"
49 " --seed, -s Specify random seed\n"
50 " --verify, -v Verify that PATH contains the expected contents\n"
51 " --create, -c Create PATH with psuedo-random contents\n"
52 " --flush, -f Flush cache\n"
53 " --help, -h Display usage message\n"
54 " --version, -V Display version string\n");
57 // Possible modes of operation
64 // Report an error and exit
65 static void fatal(int errno_value, const char *fmt, ...) {
67 fprintf(stderr, "ERROR: ");
69 vfprintf(stderr, fmt, ap);
72 fprintf(stderr, ": %s", strerror(errno_value));
77 // Evict whatever FP points to from RAM
78 static void flushCache(FILE *fp) {
79 // drop_caches only evicts clean pages, so first the target file is
81 if(fsync(fileno(fp)) < 0)
82 fatal(errno, "fsync");
83 #if defined DROP_CACHE_FILE
85 if((fd = open(DROP_CACHE_FILE, O_WRONLY, 0)) < 0)
86 fatal(errno, "%s", DROP_CACHE_FILE);
87 if(write(fd, "3\n", 2) < 0)
88 fatal(errno, "%s", DROP_CACHE_FILE);
90 #elif defined PURGE_COMMAND
92 if((rc = system(PURGE_COMMAND)) < 0)
93 fatal(errno, "executing %s", PURGE_COMMAND);
96 fprintf(stderr, "%s%s\n",
97 strsignal(WTERMSIG(rc)),
98 WCOREDUMP(rc) ? " (core dumped)" : "");
99 exit(WTERMSIG(rc) + 128);
101 exit(WEXITSTATUS(rc));
106 int main(int argc, char **argv) {
107 const char *seed = "hexapodia as the key insight";
108 mode_type mode = NONE;
111 while((n = getopt_long(argc, argv, "+s:vcfhV", opts, 0)) >= 0) {
113 case 's': seed = optarg; break;
114 case 'v': mode = VERIFY; break;
115 case 'c': mode = CREATE; break;
116 case 'f': flush = true; break;
117 case 'h': help(); exit(0);
118 case 'V': puts(VERSION); exit(0);
120 fatal(0, "unknown option");
126 fatal(0, "must specify one of --verify or --create");
128 fatal(0, "excess arguments");
129 if(argc < (mode == VERIFY ? 1 : 2))
130 fatal(0, "insufficient arguments");
131 const char *path = argv[0];
136 size = strtoll(argv[1], &end, 10);
138 fatal(errno, "invalid size");
140 fatal(0, "invalid size");
141 if(!strcmp(end, "K"))
143 else if(!strcmp(end, "M"))
145 else if(!strcmp(end, "G"))
146 size *= 1024 * 1024 * 1024;
148 fatal(0, "invalid size");
151 if(stat(path, &sb) < 0)
152 fatal(errno, "stat %s", path);
155 Arcfour rng(seed, strlen(seed));
156 FILE *fp = fopen(path, mode == VERIFY ? "rb" : "wb");
158 fatal(errno, "%s", path);
159 if(mode == VERIFY && flush)
161 char generated[4096], input[4096];
162 long long remain = size;
164 size_t bytesGenerated = (remain > (ssize_t)sizeof generated
167 rng.stream(generated, bytesGenerated);
169 fwrite(generated, 1, bytesGenerated, fp);
171 fatal(errno, "%s", path);
173 size_t bytesRead = fread(input, 1, bytesGenerated, fp);
175 fatal(errno, "%s", path);
176 if(bytesRead < bytesGenerated)
177 fatal(0, "%s: truncated at %lld/%lld bytes",
178 path, (size - remain + bytesRead), size);
179 if(memcmp(generated, input, bytesGenerated)) {
180 for(size_t n = 0; n < bytesGenerated; ++n)
181 if(generated[n] != input[n])
182 fatal(0, "%s corrupted at %lld/%lld bytes (expected %d got %d)",
183 path, size - remain + n, size,
184 (unsigned char)generated[n], (unsigned char)input[n]);
187 remain -= bytesGenerated;
189 if(mode == VERIFY && getc(fp) != EOF)
190 fatal(0, "%s: extended beyond %lld bytes",
192 if(mode == CREATE && flush) {
194 fatal(errno, "%s", path);
198 fatal(errno, "%s", path);