WebSVN – planix.SVN – Blame – /os/branches/feature_posix/sys/src/cmd/gzip/gunzip.c

Rev	Author	Line No.	Line
2	-	1	`#include <u.h>`
		2	`#include <libc.h>`
		3	`#include <bio.h>`
		4	`#include <flate.h>`
		5	`#include "gzip.h"`
		6
		7	`typedef struct GZHead GZHead;`
		8
		9	`struct GZHead`
		10	`{`
		11	`ulong mtime;`
		12	`char *file;`
		13	`};`
		14
		15	`static int crcwrite(void bout, void buf, int n);`
		16	`static int get1(Biobuf *b);`
		17	`static ulong get4(Biobuf *b);`
		18	`static int gunzipf(char *file, int stdout);`
		19	`static int gunzip(int ofd, char ofile, Biobuf bin);`
		20	`static void header(Biobuf bin, GZHead h);`
		21	`static void trailer(Biobuf *bin, long wlen);`
		22	`static void error(char*, ...);`
		23	`#pragma varargck argpos error 1`
		24
		25	`static Biobuf bin;`
		26	`static ulong crc;`
		27	`static ulong *crctab;`
		28	`static int debug;`
		29	`static char *delfile;`
		30	`static vlong gzok;`
		31	`static char *infile;`
		32	`static int settimes;`
		33	`static int table;`
		34	`static int verbose;`
		35	`static int wbad;`
		36	`static ulong wlen;`
		37	`static jmp_buf zjmp;`
		38
		39	`void`
		40	`usage(void)`
		41	`{`
		42	`fprint(2, "usage: gunzip [-ctvTD] [file ....]\n");`
		43	`exits("usage");`
		44	`}`
		45
		46	`void`
		47	`main(int argc, char *argv[])`
		48	`{`
		49	`int i, ok, stdout;`
		50
		51	`stdout = 0;`
		52	`ARGBEGIN{`
		53	`case 'D':`
		54	`debug++;`
		55	`break;`
		56	`case 'c':`
		57	`stdout++;`
		58	`break;`
		59	`case 't':`
		60	`table++;`
		61	`break;`
		62	`case 'T':`
		63	`settimes++;`
		64	`break;`
		65	`case 'v':`
		66	`verbose++;`
		67	`break;`
		68	`default:`
		69	`usage();`
		70	`break;`
		71	`}ARGEND`
		72
		73	`crctab = mkcrctab(GZCRCPOLY);`
		74	`ok = inflateinit();`
		75	`if(ok != FlateOk)`
		76	`sysfatal("inflateinit failed: %s", flateerr(ok));`
		77
		78	`if(argc == 0){`
		79	`Binit(&bin, 0, OREAD);`
		80	`settimes = 0;`
		81	`infile = "<stdin>";`
		82	`ok = gunzip(1, "<stdout>", &bin);`
		83	`}else{`
		84	`ok = 1;`
		85	`if(stdout)`
		86	`settimes = 0;`
		87	`for(i = 0; i < argc; i++)`
		88	`ok &= gunzipf(argv[i], stdout);`
		89	`}`
		90
		91	`exits(ok ? nil: "errors");`
		92	`}`
		93
		94	`static int`
		95	`gunzipf(char *file, int stdout)`
		96	`{`
		97	`char ofile[256], *s;`
		98	`int ofd, ifd, ok;`
		99
		100	`infile = file;`
		101	`ifd = open(file, OREAD);`
		102	`if(ifd < 0){`
		103	`fprint(2, "gunzip: can't open %s: %r\n", file);`
		104	`return 0;`
		105	`}`
		106
		107	`Binit(&bin, ifd, OREAD);`
		108	`if(Bgetc(&bin) != GZMAGIC1 \|\| Bgetc(&bin) != GZMAGIC2 \|\| Bgetc(&bin) != GZDEFLATE){`
		109	`fprint(2, "gunzip: %s is not a gzip deflate file\n", file);`
		110	`Bterm(&bin);`
		111	`close(ifd);`
		112	`return 0;`
		113	`}`
		114	`Bungetc(&bin);`
		115	`Bungetc(&bin);`
		116	`Bungetc(&bin);`
		117
		118	`if(table)`
		119	`ofd = -1;`
		120	`else if(stdout){`
		121	`ofd = 1;`
		122	`strcpy(ofile, "<stdout>");`
		123	`}else{`
		124	`s = strrchr(file, '/');`
		125	`if(s != nil)`
		126	`s++;`
		127	`else`
		128	`s = file;`
		129	`strecpy(ofile, ofile+sizeof ofile, s);`
		130	`s = strrchr(ofile, '.');`
		131	`if(s != nil && s != ofile && strcmp(s, ".gz") == 0)`
		132	`*s = '\0';`
		133	`else if(s != nil && strcmp(s, ".tgz") == 0)`
		134	`strcpy(s, ".tar");`
		135	`else if(strcmp(file, ofile) == 0){`
		136	`fprint(2, "gunzip: can't overwrite %s\n", file);`
		137	`Bterm(&bin);`
		138	`close(ifd);`
		139	`return 0;`
		140	`}`
		141
		142	`ofd = create(ofile, OWRITE, 0666);`
		143	`if(ofd < 0){`
		144	`fprint(2, "gunzip: can't create %s: %r\n", ofile);`
		145	`Bterm(&bin);`
		146	`close(ifd);`
		147	`return 0;`
		148	`}`
		149	`delfile = ofile;`
		150	`}`
		151
		152	`wbad = 0;`
		153	`ok = gunzip(ofd, ofile, &bin);`
		154	`Bterm(&bin);`
		155	`close(ifd);`
		156	`if(wbad){`
		157	`fprint(2, "gunzip: can't write %s: %r\n", ofile);`
		158	`if(delfile)`
		159	`remove(delfile);`
		160	`}`
		161	`delfile = nil;`
		162	`if(!stdout && ofd >= 0)`
		163	`close(ofd);`
		164	`return ok;`
		165	`}`
		166
		167	`static int`
		168	`gunzip(int ofd, char ofile, Biobuf bin)`
		169	`{`
		170	`Dir *d;`
		171	`GZHead h;`
		172	`int err;`
		173
		174	`h.file = nil;`
		175	`gzok = 0;`
		176	`for(;;){`
		177	`if(Bgetc(bin) < 0)`
		178	`return 1;`
		179	`Bungetc(bin);`
		180
		181	`if(setjmp(zjmp))`
		182	`return 0;`
		183	`header(bin, &h);`
		184	`gzok = 0;`
		185
		186	`wlen = 0;`
		187	`crc = 0;`
		188
		189	`if(!table && verbose)`
		190	`fprint(2, "extracting %s to %s\n", h.file, ofile);`
		191
		192	`err = inflate((void)ofd, crcwrite, bin, (int()(void*))Bgetc);`
		193	`if(err != FlateOk)`
		194	`error("inflate failed: %s", flateerr(err));`
		195
		196	`trailer(bin, wlen);`
		197
		198	`if(table){`
		199	`if(verbose)`
		200	`print("%-32s %10ld %s", h.file, wlen, ctime(h.mtime));`
		201	`else`
		202	`print("%s\n", h.file);`
		203	`}else if(settimes && h.mtime && (d=dirfstat(ofd)) != nil){`
		204	`d->mtime = h.mtime;`
		205	`dirfwstat(ofd, d);`
		206	`free(d);`
		207	`}`
		208
		209	`free(h.file);`
		210	`h.file = nil;`
		211	`gzok = Boffset(bin);`
		212	`}`
		213	`}`
		214
		215	`static void`
		216	`header(Biobuf bin, GZHead h)`
		217	`{`
		218	`char *s;`
		219	`int i, c, flag, ns, nsa;`
		220
		221	`if(get1(bin) != GZMAGIC1 \|\| get1(bin) != GZMAGIC2)`
		222	`error("bad gzip file magic");`
		223	`if(get1(bin) != GZDEFLATE)`
		224	`error("unknown compression type");`
		225
		226	`flag = get1(bin);`
		227	`if(flag & ~(GZFTEXT\|GZFEXTRA\|GZFNAME\|GZFCOMMENT\|GZFHCRC))`
		228	`fprint(2, "gunzip: reserved flags set, data may not be decompressed correctly\n");`
		229
		230	`/* mod time */`
		231	`h->mtime = get4(bin);`
		232
		233	`/* extra flags */`
		234	`get1(bin);`
		235
		236	`/* OS type */`
		237	`get1(bin);`
		238
		239	`if(flag & GZFEXTRA)`
		240	`for(i=get1(bin); i>0; i--)`
		241	`get1(bin);`
		242
		243	`/* name */`
		244	`if(flag & GZFNAME){`
		245	`nsa = 32;`
		246	`ns = 0;`
		247	`s = malloc(nsa);`
		248	`if(s == nil)`
		249	`error("out of memory");`
		250	`while((c = get1(bin)) != 0){`
		251	`s[ns++] = c;`
		252	`if(ns >= nsa){`
		253	`nsa += 32;`
		254	`s = realloc(s, nsa);`
		255	`if(s == nil)`
		256	`error("out of memory");`
		257	`}`
		258	`}`
		259	`s[ns] = '\0';`
		260	`h->file = s;`
		261	`}else`
		262	`h->file = strdup("<unnamed file>");`
		263
		264	`/* comment */`
		265	`if(flag & GZFCOMMENT)`
		266	`while(get1(bin) != 0)`
		267	`;`
		268
		269	`/* crc16 */`
		270	`if(flag & GZFHCRC){`
		271	`get1(bin);`
		272	`get1(bin);`
		273	`}`
		274	`}`
		275
		276	`static void`
		277	`trailer(Biobuf *bin, long wlen)`
		278	`{`
		279	`ulong tcrc;`
		280	`long len;`
		281
		282	`tcrc = get4(bin);`
		283	`if(tcrc != crc)`
		284	`error("crc mismatch");`
		285
		286	`len = get4(bin);`
		287
		288	`if(len != wlen)`
		289	`error("bad output length: expected %lud got %lud", wlen, len);`
		290	`}`
		291
		292	`static ulong`
		293	`get4(Biobuf *b)`
		294	`{`
		295	`ulong v;`
		296	`int i, c;`
		297
		298	`v = 0;`
		299	`for(i = 0; i < 4; i++){`
		300	`c = Bgetc(b);`
		301	`if(c < 0)`
		302	`error("unexpected eof reading file information");`
		303	`v \|= c << (i * 8);`
		304	`}`
		305	`return v;`
		306	`}`
		307
		308	`static int`
		309	`get1(Biobuf *b)`
		310	`{`
		311	`int c;`
		312
		313	`c = Bgetc(b);`
		314	`if(c < 0)`
		315	`error("unexpected eof reading file information");`
		316	`return c;`
		317	`}`
		318
		319	`static int`
		320	`crcwrite(void out, void buf, int n)`
		321	`{`
		322	`int fd, nw;`
		323
		324	`wlen += n;`
		325	`crc = blockcrc(crctab, crc, buf, n);`
		326	`fd = (int)(uintptr)out;`
		327	`if(fd < 0)`
		328	`return n;`
		329	`nw = write(fd, buf, n);`
		330	`if(nw != n)`
		331	`wbad = 1;`
		332	`return nw;`
		333	`}`
		334
		335	`static void`
		336	`error(char *fmt, ...)`
		337	`{`
		338	`va_list arg;`
		339
		340	`if(gzok)`
		341	`fprint(2, "gunzip: %s: corrupted data after byte %lld ignored\n", infile, gzok);`
		342	`else{`
		343	`fprint(2, "gunzip: ");`
		344	`if(infile)`
		345	`fprint(2, "%s: ", infile);`
		346	`va_start(arg, fmt);`
		347	`vfprint(2, fmt, arg);`
		348	`va_end(arg);`
		349	`fprint(2, "\n");`
		350
		351	`if(delfile != nil){`
		352	`fprint(2, "gunzip: removing output file %s\n", delfile);`
		353	`remove(delfile);`
		354	`delfile = nil;`
		355	`}`
		356	`}`
		357
		358	`longjmp(zjmp, 1);`
		359	`}`

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